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Synthesis, characterization and biological studies of organotin(IV) complexes with hydrazone ligand

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Four organotin(IV) complexes with general formula [RSnCln−1(TCB)] [R = Ph2, n = 2 (2); R = Me, n = 3 (3); R = Bu, n = 3 (4); R = Ph, n = 3 (5)] have been synthesized by direct reaction of thiophene-2-carboxaldehyde benzhydrazone ligand [HTCB, (1)], base and organotin(IV) chloride in absolute methanol under N2 atmosphere. All organotin(IV) complexes were characterized by elemental analyses, molar conductivity, UV–Vis, FT-IR, 1H and 13C NMR spectral studies. Among them, diphenyltin(IV) complex (2) has also been characterized by X-ray crystallography diffraction analyses. The cytotoxicity of the hydrazone ligand as well as its organotin(IV) complexes (2–5) were determined with Artemia salina. While no-choice bioassay was employed on Coptotermes sp. to evaluate the termiticidal effect of all the complexes. Besides, the ligand (1) and its organotin(IV) complexes (2–4) were also tested against five types of bacteria namely Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi.

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... The bands of ν (N-H) and ν (C=O) were absent in the spectra of the metal chloride complexes (4, 5,14,17) suggesting coordination via enol-form, by the deprotonation of the N-H proton, during the complexation process similar observation were noticed in the IR spectra of the deprotonated bis-complexes (7)(8)(9)(10)(11)(18)(19)(20)(21)(22) in which the ν (N-H) and ν (C=O) are not observed due to enolization of carbonyl group of the ligands due to complex formation. The appearance of anew ν (c-o) band in these complexes at the region 1286-1302cm -1 suggest bonding of the ligands to the metal ions through deprotonated (C-O) group (Abu Affan et al., 2009). ...
... This indicates the coordination of one of the nitrogen atom of N-N group with metal (Singh et al., 2013). This phenomenone is owing to the diminution of the lone pair electrons repulsion which come from the two adjacent nitrogen atoms, by sharing the electrons out to the metal ion (Abu Affan et al., 2009). ...
... The medium intensity band observed at 850 cm -1 in the spectrum of the ligand TCPH due to ν (C-S-C) of thiophene ring is also unaffected by coordination and remains almost at the same position in the metal complexes, which indicates the non-involvement of thiophene sulfur atom in bonding (Singh et al., 2011;Abu Affan et al., 2009). ...
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A series of metal complexes of Th(IV), UO 2 (II), Co(II), Ni(II), Cu(II) and Zn(II) with 2-acetyl furan picolinoyl hydrazone (AFPH) and 2-thiophen carboxaldehyde picolinoyl hydrazone (TCPH) have been synthesized. The complexes were characterized by elemental analyses (metal and Cl), molar conductance, magnetic susceptibility and spectral (IR, UV-Vis) measurements. The ligands act as neutral tridentate in metal chloride complexes of the general formula [ML(H 2 O)Cl 2 ], [L=AFPH, M=Co(II), Ni(II), Cu(II). L = TCPH, M = Co(II), Ni(II), Zn(II)] and [UO 2 LCl 2 ] (L = AFPH, TCPH) coordinated through carbonyl oxygen, azomethine nitrogen and pyridine nitrogen atoms. The physico _ chemical studies suggest octahedral and pentagonal bipyramidal geometries respectively. On the other hand, the ligands act as monobasic tridentate coordinated through the enolic oxygen, the azomethine nitrogen and the pyridine nitrogen atoms in the deprotonated complexes of the types [M(L-H)Cl] 2 , [L=AFPH, M=Zn(II); L=TCPH, M=Cu(II)], [Th(L-H) 2 Cl 2 ] (L=AFPH, TCPH), and [M(L-H) 2 ] [L=(AFPH, TCPH), M=Co(II), Ni(II), Cu(II), Zn(II), UO 2 (II)] forming binuclear square pyramidal and octahedral mononuclear metal complexes. Hexagonal bipyramidal geometry proposed was for the dioxouranium(VI) complexes and square antiprismatic or dodecahedral geometries for Th(IV) complexes.
... All biologically important metal ions can form complexes and the number of different chemical species which can be coordinated with these metal ions is very large. During the past few decades, a lot of scientist research groups operated through specialization in the direction of drug discovery, by studying the simplest species that use metal ions and researching them as whole compound; for example, they suggested the addition of metal ion to antibiotics to facilitate their spread throughout the body [2]. The development of drug resistance as well as the appearance of undesirable side effects of certain antibiotics has led to the search of new antimicrobial agents with the goal to discover new chemical structures which overcome the above disadvantages. ...
... From the foregoing review a number of things can be gleaned. First is the fact that further studies at molecular levels should be carried out to further elucidate on the mode of action of Ni(SHA) 2 . Conclusively, it is imperative to point out that a number of studies have been carried out on the metal complexes of Nickel nonetheless, as pointed out before some vacuum still remain. ...
... Although some of the metal complexes have also entered phase-I and phase-II clinical trials Sadler 2000, Zhang andLippard 2003), their toxicity and acquired cellular resistance following the administration of the drug are still beyond comprehension (Arjmand and Sayeed 2010). Extensive research is still underway to find an unambiguous explanation for the mode of action of organotin complexes on the molecular level, but so far, no generalized and clear-cut explanation has been reached, which would be applicable and explanatory to the activity of majority of the known organotin complexes (Affan et al. 2009, Arjmand and Sayeed 2010, Chen et al. 2011. In this review, an attempt has been made to explore those factors that affect the mode of action and therapeutic properties of organotin complexes. ...
... Bulky organic groups may enhance the dissociation of the complex to form ionic components of that complex. These bulky groups also increase the permeability of the complexes into the cells and cause casualty (Affan et al. 2009). An example is shown in Figure 6C by complex 8. ...
Article
Organotin complexes are being extensively studied and screened for their therapeutic potential. Although many recent advances and achievements in this field have been made, the exact mode of action of these complexes is yet to be unveiled. In the present review, an attempt has been made to correlate the therapeutic properties of organotin complexes with their structural features and the environment in which these interact with biological systems. The mechanism, various modes of interaction with biological systems, and physiological target sites of organotin complexes have been highlighted as well.
... They undergo easy dehydration to 1,3,4-oxadiazoles that present a variety of biological activities [33,34]. Hydrazide-hydrazones provide interesting properties in the field of supramolecular architecture [35][36][37][38][39], organic synthesis [33,40], chemo-and physical imaging [41][42][43][44], coordination [45][46][47][48][49], and in inorganic chemistry [50][51][52][53]. The numerous biologically active hydrazide-hydrazones are particularly worth paying attention to [54]. ...
... They undergo easy dehydration to 1,3,4oxadiazoles that present a variety of biological activities [33,34]. Hydrazide-hydrazones provide interesting properties in the field of supramolecular architecture [35][36][37][38][39], organic synthesis [33,40], chemo-and physical imaging [41][42][43][44], coordination [45][46][47][48][49], and in inorganic chemistry [50][51][52][53]. The numerous biologically active hydrazide-hydrazones are particularly worth paying attention to [54]. ...
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Laccase from pathogenic fungi participates in both the delignification and neutralization of phytoantibiotics. Furthermore, it interferes with the hormone signaling in plants and catalyzes melanization. Infections of these pathogens contribute to loss in forestry, agriculture, and horticulture. As there is still a need to expand knowledge on efficient defense strategies against phytopathogenic fungi, the present study aimed to reveal more information on the molecular mechanisms of laccase inhibition with natural and natural-like carboxylic acid semi-synthetic derivatives. A set of hydrazide-hydrazones derived from carboxylic acids, generally including electron-rich arene units that serve as a decoy substrate, was synthesized and tested with laccase from Trametes versicolor. The classic synthesis of the title inhibitors proceeded with good to almost quantitative yield. Ninety percent of the tested molecules were active in the range of KI = 8–233 µM and showed different types of action. Such magnitude of inhibition constants qualified the hydrazide-hydrazones as strong laccase inhibitors. Molecular docking studies supporting the experimental data explained the selected derivatives’ interactions with the enzyme. The results are promising in developing new potential antifungal agents mitigating the damage scale in the plant cultivation, gardening, and horticulture sectors.
... The molecule in the title hydrate, (I), was synthesised as part of an on-going study into biological studies of organotin compounds (Gielen & Tiekink, 2005; Affan et al., 2009 ). The thiourea derivative in (I) is effectively planar with the maximum deviation of any of the torsion angles from 0 or 180° being 4.6 (2)° for N4—C10—C12—C13 and -174.62 (15)° for C11—C10—C12—C13. ...
Article
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In the title compound, C(17)H(18)N(4)O(2)S·H(2)O, the thio-urea derivative is almost planar, with an r.m.s. deviation for the non-H atoms of 0.057 Å. The hydroxyl groups lie to the same side of the mol-ecule as the thione S atom, a conformation that allows the formation of intra-molecular O-H⋯S and O-H⋯N hydrogen bonds. In the crystal structure, the thio-urea and water mol-ecules self-assemble into a two-dimensional array by a combination of O(water)-H⋯O(hydrox-yl), N-H⋯O(water) and O(water)-H⋯S hydrogen bonds and C-H⋯π inter-actions.
... We have found that the strong intensity absorption peaks at 680-700 cm −1 are due to the stretching vibration of Ni-Cl bond. According to [36,37] Ni-N bonding, strong IR spectrum is found at 511.14 cm −1 and 588. 29 ...
Article
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We represent a metal complex which has been synthesized by the simple reaction with Ni(II) chloride and pyridine (as a lignd) affording a complex having the molecular formula [NiC5H5N2Cl2], characterized on the basis of elemental analyses, electronic, infrared, 1H NMR, 13C NMR spectra, magnetic susceptibility, and also aid of molar conductivity measurement. Conductivity measurement reveals nonelectrolytic nature of the complex. IR and 13C NMR spectra reveal the presence of cis- and trans-structure. On the basis of above analyses the square planar cis- and trans-structures are proposed for the prepared complex.
... For related studies on organotin compounds, see: Affan et al. (2009); Zukerman Schpector et al. (2009). For the structure of the dichloromethane solvate of the title compound, see: Cui et al. (2007). ...
Article
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Two independent but very similar mol-ecules comprise the asymmetric unit of the title compound, [Sn(CH(3))(2)(C(18)H(12)N(2)O(3))]. Each Sn atom is coordinated by two methyl groups and two O atoms and an N atom from the dinegative tridentate ligand. The resultant C(2)NO(2) donor set defines a coordination geometry inter-mediate between square-pyramidal and trigonal-pyramidal, with a small tendency towards the former. Zigzag chains running along the a axis mediated by O-H⋯N hydrogen bonding characterize the crystal packing. These are connected into layers in the ab plane by a combination of C-H⋯N and π-π [centroid-centroid distances = 3.658 (2) and 3.6740 (18) Å] inter-actions. The layers are connected along the c axis via C-H⋯O inter-actions.
... For background and recent studies on the biological activity of tin/organotin compounds, see: Gielen & Tiekink (2005); Affan et al. (2009). ...
Article
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The 13 non-H atoms comprising the title compound, C(9)H(10)N(2)O(2), are close to planar (r.m.s. deviation = 0.140 Å), with maximum deviations of 0.292 (1) and 0.210 (1) Å to either side of the least-squares plane exhibited by the hy-droxy and carbonyl O atoms, respectively. The observed conformation is stabilized by an intra-molecular O-H⋯N hydrogen bond. The conformation about the N=C double bond [1.2909 (16) Å] is E. The hy-droxy OH group also forms an inter-molecular hydrogen bond to a carbonyl O atom, and the amine H atom similarly forms an N-H⋯O hydrogen bond to a second carbonyl O atom. The result is the formation of a double layer with a flat topology. Layers stack along the a-axis direction connected by C-H⋯π inter-actions.
... In general tin(IV) chelated complexes deactivate various cellular enzymes which play important roles in different metabolic pathways for the microorganisms. However, the antibacterial activity of 1 and 2-7 are lower than reported mono-/di-organotin(IV) complexes [21,22]. ...
Article
Six new organotin(IV) complexes were synthesized by direct reaction of RSnCl3 (R = Me, Bu and Ph) or R2SnCl2 (R = Me, Bu and Ph) and 2-hydroxyacetophenone thiocarbohydrazone [H(2)APTC] under purified nitrogen in the presence of base in 1 : 2 : 1 molar ratio (metal: base: ligand). Complexes 2-7 have been characterized by elemental analyses, molar conductivity, UV-Visible, IR and H-1 NMR spectral studies. Complexes 2-7 are non-electrolytes. The molecular structure of [Me2Sn(APTC)] center dot (C2H5OH) (5) has been determined by X-ray diffraction analysis. The thiocarbohydrazone ligand (1) and 2-7 have been tested for antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi and Enterococci aeruginosa.
... Organotin compounds have a wide range of applications and they are amongst the most widely used organometallic chemicals. The organotin (IV) compounds possess significant biological activities Wu et al. 2009;Alama et al. 2009;Affan et al 2009). These compounds have been found as antitumor (Mohan et al., 1988;Ruan et al., 2011), antibacterial (Maiti et al., 1988;Gleeson et al. 2008), antifungal (Manav et al., 2000;Singh and Kaushik, 2008) and antiviral (Singh et al., 2000). ...
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Problem statement: The growing interest in the chemistry of sulphur donor ligands are due to their encouraging anticancer, antibacterial and antifungal activities as well as their widespread industrial application. Dithiocarbamates belong to this class and much attention has been paid to them. Approach: Novel organotin compounds with the molecular formula R m Sn[S 2 CN(CH 3)(C 6 H 11)] 4-m (where m = 2, R = CH 3 , C 2 H 5; m = 3, R = C 6 H 5) have been synthesized using in situ method. These compounds were characterized by elemental analysis, IR, 1 H and 13 C NMR spectroscopy. Results: Elemental analysis revealed that all compounds were of good purity. Infrared spectra of the compounds showed that the thioureide ν(C-N) band was in the region 1450-1500 cm −1 . The unsplitting band of ν(C-S) in the region 974-979 cm −1 indicated the bidentate nature of the chelated dithiocarbamato legends. The 13 C NMR chemical shift of the carbon atom in the N-CS 2 group appeared in the range of 196.29-199.82 ppm. Single crystal analysis from one of these compounds showed that the chelating mode of the dithiocarbamate groups was isobidentate. These compounds have been screened for antibacterial activity against four bacteria; Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aeruginosa and Bacillus subtilis. Only one of these compounds shows promising results against S. aureus and S. typhi. Cytotoxicity screening on human leukemic promyelocyte HL-60 cells found that two of these compounds were very active with CD 50 values of 0.87 and 0.18 µg mL −1 . Conclusion: The studied compounds were found to have the potential in biological activity especially in cytotoxicity where this possibly can be used for clinical trials after further research.
... The spectrum of Bu 2 Sn(naphPTB) 2 exhibits an intense peak at [m/z,%intensity = 870(-3H + ), 48] corresponding to molecular ion peak while the other intense peak at [m/z,%intensity = 320, 90] corresponds to the ligand moiety. In addition to these, some weak peaks at [m/z,%intensity = 815(-H+), 11], [m/z,%intensity = 786(-H+), 18], and [m/z,%intensity = 640, 32] are also observed, which may be due to loss of respectively, one -(CH 2 ) 3 CH 3 group, two -(CH 2 ) 2 CH 3 groups, and (Bu) 2 Sn + moiety from the complex. ...
Article
Organotin complexes of the type Ph3SnL and Bu2SnL2 (where Ph = phenyl and Bu = butyl, HL = 1-phenyl-2, 4-dithiobiuret (PDTBH), 1-(3-acetylphenyl)-2, 4-dithiobiuret (AcPDTBH), 1-(4-ethoxyphenyl)-2, 4-dithiobiuret (EtOPDTBH)), have been prepared. Molar conductance studies show the nonionic behavior of the complexes. FAB mass spectra exhibit their monomeric nature. 1H NMR and 13C NMR spectra of the complexes are consistent with the proposed stoichiometry of the complexes. Infrared spectra indicate anionic bidentate coordinating behavior of the ligands. Powder X-ray diffraction patterns of the complex Ph3Sn (PDTB) are indicative of monoclinic system.
... The Sn-N2, Sn-O1 and Sn-O2 bond lengths are 2.155(2), 2.120(2) and 2.212(1) Å, respectively, which are very similar to the sum of the covalent radii of Sn-N (2.15 Å) and Sn-O (2.10 Å) [35][36][37], indicating firm bonding of N2, O1 and O2 with the tin core. ...
Article
Two new organotin(IV) complexes, [SnPh2(L)] (1) and [SnMe2(L)] (2), have been synthesized from the reaction of SnPh2Cl2 and SnMe2Cl2 with a Schiff base, 3-(3-hydroxypyridin-2-ylamino)-1-phenylbut-2-en-1-one (H2L), derived from 2-amino-3-hydroxypyridine and benzoylacetone. The new compounds have been characterized by elemental analysis, FT-IR, 1H and 119Sn NMR spectroscopy. The structures of H2L and 2 have been confirmed by X-ray crystallography. Crystals of H2L are orthorhombic with the space group P212121. This compound forms a dimer in the solid state which is held together by two intermolecular hydrogen bonds. This Schiff base exists as the keto-amine tautomeric form with one intramolecular N–H⋯O hydrogen bond. In the two complexes the Schiff base is completely deprotonated and coordinates to tin as tridentate via the imine nitrogen and phenolic and enolic oxygen atoms, and the coordination number of the tin center is five. Complex 2 crystallizes in the monoclinic space group, P21/n, and the structure is distorted square pyramidal, with the imine nitrogen in the apical position. The in vitro antibacterial activity of the Schiff base and its complexes has been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. H2L showed no activity, but the organotin(IV) complexes exhibited good activities along with the standard antibacterial drugs.
... Of interest structurally is the facile keto-enol tautomerization and availability of several potential donor sites allowing structural variety of their complexes [15]. Thus, hydrazone organotin(IV) complexes are of interest for both biological and structural reasons [16][17][18][19]. As part of our investigation dealing with organotin(IV) complexes of Schiff bases, this article presents the synthesis, structural studies, and antibacterial activities of four diorganotin(IV) complexes with two hydrazones, H 2 L a and H 2 L b (figure 1). ...
Article
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Four new diorganotin(IV) complexes, R2SnL (L = La: R = Me 1, Ph 2; L = Lb: R = Me 3, and Ph 4), have been synthesized by reaction of hydrazone ONO donors, 5-bromo-2-hydroxybenzaldehyde furan-2-carbohydrazone (H2La) and 2-hydroxynaphthaldehyde furan-2-carbohydrazone (H2Lb) with diorganotin(IV) dichloride in the presence of a base. The compounds have been investigated by elemental analysis and IR, 1H NMR, and 119Sn NMR spectroscopies. Spectroscopic studies show that the hydrazone is a tridentate dianionic ligand, coordinating via the imine nitrogen and phenolic and enolic oxygens. The structures of H2Lb and 3 have also been confirmed by X-ray crystallography. The results show that the structure of 3 is a distorted square pyramid with imine nitrogen in apical position. The in vitro antibacterial activities of ligands and complexes have been evaluated against gram-positive (Bacillus cereus and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. H2La and H2Lb show no activity but the diphenyltin(IV) complexes exhibit good activities towards two bacterial strains in comparison with standard bacterial drugs.
... For background to the biological activity of tin/organotin compounds, see: Gielen & Tiekink (2005). For related studies on organotin compounds, see: Affan et al. (2009) ...
Article
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In the title organotin compound, [Sn(C6H5)(C10H15N3O2S)Cl(H2O)], the Sn atom is coordinated by the S, O, and imine N atoms of the dinegative tridentate ligand, a chloride ligand, the ipso-C atom of a phenyl ligand and by a water mol­ecule in a distorted octa­hedral coordination environment. Coordin­ated water mol­ecules link the organotin mol­ecules by forming O—H⋯O hydrogen bonds with both carbonyl and carboxyl­ate O atoms, leading to 12-membered {⋯OCO⋯HOH⋯}2 synthons. This results in the formation of supra­molecular chains along the c axis. The chains pack in the ac plane and stack along the b axis with links between layers afforded by N—H⋯Cl hydrogen bonds.
... Among the organotin(IV) complexes (2)(3)(4)(5)(6), the diphenyltin(IV) complex (3) shows higher toxicity compare to the other complexes. This might be due to the presence of bulky phenyl groups can dissociate the complex to form ionic compounds and increase the permeability of the compound into the cell [15]. ...
Article
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Five new organotin(IV) complexes of ortho-vanillin-2-hydrazinopyridine hydrazone with formula [R n Sn-Cl 4–n (VHP)] [R = Me 2 , n = 2 (2); R = Ph 2 , n = 2 (3); R= nBu 2 , n = 2 (4); R = nBu, n = 2 (5) and R = 1, n = 0 (6)] have been synthesized by direct reaction of ortho-vanillin-2-hydrazinopyridine hydrazone [(VHP), (1)], base and organotin(IV) chloride(s) in absolute metha-nol. The hydrazone ligand [(VHP), (1)] and its organo-tin(IV) complexes (2-6) have been characterized by UV-Visible, FT-IR and 1 H NMR spectral studies. Spectroscopic data suggested that in the complexes (2-4), the ligand (1) acted as a neutral bidentate ligand and is coordinated to the tin(IV) atom via the azome-thine nitrogen and pyridyl nitrogen atoms, whereas the ligand (1) acted as a uninegative tridentate ligand and coordinated to the tin(IV) atom through phenolic-O, azomethine-N and pyridyl-N atoms in complexes (5-6). The toxicity of the ligand (1) and its organotin (IV) complexes (2-6) were determined against Artemia salina. Organotin(IV) complexes showed moderate ac-tivity against Artemia salina. The ligand (1) and its organotin(IV) complexes (2-6) were also tested against four types of bacteria namely Bacillus cereus, Staphy-lococcus aureus, Escherichia coli and Enterobacter aerogenes. All organotin(IV) complexes and the free ligand (1) showed better antibacterial activities against bacteria. Among the organotin(IV) complexes (2-6), diphenyltin(IV) complex (3) showed higher activity against the four types of bacteria.
... Among the organotin(IV) complexes (2)(3)(4)(5)(6), the diphenyltin(IV) complex (3) shows higher toxicity compare to the other complexes. This might be due to the presence of bulky phenyl groups can dissociate the complex to form ionic compounds and increase the permeability of the compound into the cell [15]. ...
... 19 ). The methyl group are further away from one another providing enough room for oxygen atom of the adjacent molecule to interact with Sn atom (Fig. 3) [31]. ...
Article
Organotin(IV) derivatives ONO schiff base Dimeric Supramolecular Antifungal Antibacterial Antileishmanial Antiurease a b s t r a c t The paper describes the synthesis and structural characterization of six new diorganotin(IV) compounds 1e6, [R 2 SnL] and a monoorganotin(IV) derivative, C 4 H 9 SnClL (7). Here L ¼ N 0 -(5-bromo-2-oxidobenzylidene)-N-(oxidomethylene)hydrazine ligand with ONO tridentate chelation capability and R ¼ CH 3 (1), C 2 H 5 (2), n-C 4 H 9 (3), C 6 H 5 (4), C 8 H 17 (5), tert-C 4 H 9 (6), The packing diagram offers a supra-molecular structure for 1 and a dimeric structure for 4 with distorted square-pyramidal and distorted trigonal geometry, respectively. The different geometry of 1 than 4 can be attributed to the presence of intermolecular non-covalent Sn—O and Sn—H interactions in the former. The antifungal, antibacterial, antiurease and antileishmanial activities of these complexes proved them to be active biologically and may be formulated as new metal-based drugs in future. Ó 2011 Elsevier B.V. All rights reserved.
... Hydrazone derivatives have been widely investigated for their biological activity [2][3][4][5]. Recently, the crystal structures of a number of hydrazone derivatives have been reported [6][7][8][9]. ...
Article
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C15H12Cl2N2O3, monoclinic, Clcl (no. 9), a = 10.845(2) angstrom, b = 12.773(2) angstrom, c = 10.853(2) angstrom, beta = 96.688(2)degrees, V = 1493.1 angstrom(3), Z = 4, R-gt(F) = 0.041, wR(ref)(F-2) = 0.081, T = 298 K.
... Hydrazone derivatives have been widely investigated for their biological properties1234. In recent years, the crystal structures of anumber of hydrazone derivatives have been reported5678. In the present work, an ew hydrazone derivative, N'-(5-bromo-2- hydroxy-3-methoxybenzylidene)-4-nitrobenzohydrazide monohydrate (see theFigure), was prepared and structurally characterized. ...
Article
C15H14BrN3O6, monoclinic, P2(1)/n (no. 14), a = 4.546(2) angstrom, b = 13.831(3) angstrom, c = 26.124(2) angstrom, beta = 91.146(2)degrees, V = 1642.1 angstrom(3), Z = 4, R-gt(F) = 0.0704, wR(ref)(F-2) = 0.1827, T = 298 K.
... UV-Vis spectra of the compounds 1-5 exhibited three absorption bands near 265-275, 408-412 and 475-497 nm, respectively. The new band observed at 475-479 nm indicates ligand to metal charge transfer[43]. ...
... The CH_N proton exhibits a sharp singlet at δ 8. 36-8.55 in the spectra of the ligands, is shifted slightly downfield in the spectra of the complexes in the region δ 9.13-9.61. This observation indicates the involvement of C_N chromophore in coordination [41,42]. In addition, the spectra of the hydrazone ligands show two signals in the region δ 11.40-11.98, is attributed to the ortho and para positions of phenolic OH respectively. ...
... All biologically important metal ions can form complexes and the number of different chemical species which can be coordinated with these metal ions is very large. During the past few decades, a lot of scientist research groups operated through specialization in the direction of drug discovery, by studying the simplest species that use metal ions and researching them as whole compound; for example, they suggested the addition of metal ion to antibiotics to facilitate their spread throughout the body [2]. ...
... In industrial applications, they are largely employed as catalysts in reactions to produce esters [15], polyesters [16,17] and lactones [18] at high yields. Furthermore, organotin compounds also show a wide range of important biological applications [19,20], for example, they have been demonstrated to have significant antitumor [21,22], antifungal [23,24], antiviral [25], and antibacterial [26,27] activities. ...
Article
Cobalt(II), nickel(II), copper(II) and zinc(II) complexes with 2-acetylthiophene benzoylhydrazone have been synthesized and characterized by elemental analyses, magnetic susceptibility measurements, electronic, IR, NMR and ESR spectral techniques. The molecular structures of ligand and its copper(II) complex have been determined by single crystal X-ray diffraction technique. The Cu(II) complex possesses a CuN2O2 chromophore with a considerable delocalization of charge. The structure of the complex is stabilized by intermolecular π–π stacking and C–H⋯π interactions. Hatbh acts as a monobasic bidentate ligand in all the complexes bonding through a deprotonated C–O− and >CN groups. Electronic spectral studies indicate an octahedral geometry for the Ni(II) complex while square planar geometry for the Co(II) and Cu(II) complexes. ESR spectrum of the Cu(II) complex exhibits a square planar geometry in solid and in DMSO solution. The trend g||>g⊥>2.0023 indicates the presence of an unpaired electron in the dx2-y2 orbital of Cu(II). The electro-chemical study of Cu(II) complex reveals a metal based reversible redox behavior. The Ni(II) complex shows exothermic multi-step decomposition pattern of the bonded ligand. The ligand and its most of the metal complexes show appreciable corrosion inhibition properties for mild steel in 1M HCl medium. [Co(atbh)2] complex exhibited the greatest impact on corrosion inhibition among the other compounds.
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Synthesis, characterization, and antioxidant activity of diphenyltin(IV) di-2-nitrobenzoate (2), dibutyltin(IV) di-2-nitrobenzoate (4), and triphenyltin(IV) 2-nitrobenzoate (6) using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) method has been successfully carried out. All compounds were well characterized by some spectroscopy techniques of UV, IR, NMR and based on physical technique by microelemental analysis. The result showed that diphenyltin(IV) di-2-nitrobenzoate was the most active in the antioxidant activity test, with an IC 50 value of 8.6 μg/mL compared to the other compounds in which the dibutyltin(IV) di-2-nitrobenzoate and triphenyltin(IV) 2-nitrobenzoate have IC 50 values of 12.29 μg/mL and 27.28 μg/mL, respectively, which indicated that compounds 6 and 9 were categorized active antioxidant activity. However the IC 50 values of these compounds were higher than the positive control, ascorbic acid with IC 50 value of 0.66 μg/mL.
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Divalent Co, Ni and Cu hydrazone complexes containing [N'-(phenyl(pyridine-2-yl)methylidene) benzohydrazide] ligand were synthesised and characterised. Interactions of these complexes with DNA revealed an intercalative mode of binding between them. Further, all the hydrazone chelates showed moderate ability to cleave pUC19 DNA. Synchronous fluorescence spectra proved that the interaction of metal complexes with bovine serum albumin (BSA) resulted in a conformational change of the latter. Assay on the cytotoxicity of the above complexes against HeLa tumor cells and NIH 3T3 normal cells revealed that the complexes are toxic only against tumor cells but not to normal cells. In all the biological assays, the complex with copper ion as the metal center showed enhanced activities than the other two.
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Some new diorganotin(IV) derivatives formulated as R2SnL (where R = Me, Bu, Ph and Oct) were obtained upon treatment of diorganotin(IV) precursors with acylhydrazones [H2La = N’-(2-hydroxy-3-methoxybenzylidene)furan-2-carbohydrazide, H2Lb = N’-(5-chloro-2-hydroxybenzylidene)furan-2-carbohydrazide and H2Lc = N’-(2-hydroxy-5-nitrobenzylidene)furan-2-carbohydrazide] derived from Schiff base condensation of furan-2-carbohydrazide and substituted salicylaldehydes in methanol in appropriate molar ratio. The enolic tridentate chelating mode of the acylhydrazones towards the diorganotin moieties [R2Sn(IV)]²⁺ was ascertained by micro-analysis and various spectroscopic techniques viz., Fourier-transform infrared (FT-IR), multinuclear (¹H, ¹³C and ¹¹⁹Sn) magnetic resonance (NMR) and electrospray ionization mass (ESMS) spectrometry. The single crystal X-ray diffraction investigation of Me2SnLb and Ph2SnLb demonstrates that they crystallize in monoclinic space groups ‘P 21’ and ‘P 21/c’ respectively, and comprised of crystallographically discrete 2 and 4 molecules in their respective unit cells. Both mononuclear complexes adopt a highly distorted square-pyramidal geometry (SP) wherein the imine nitrogen preferably occupies the apical site whereas the more electronegative enolic and phenolic oxygen atoms of the ligand and two carbon atoms of the methyl/phenyl groups of the organotin(IV) moiety align themselves equatorially around the five-coordinated tin center in a square plane. Diorganotin(IV) derivatives were also analyzed in air by thermo-gravimetric (TG, DTG and DTA) techniques to elucidate their thermal stability and decomposition trends.
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2012): Synthesis, spectral and structural investigations, theoretical studies, and antibacterial activity of 4-(2-hydroxynaphthalen-3-ylamino)pent-3-en-2-one and its diphenyltin(IV) complex, Journal of Coordination Chemistry, 65:10, 1712-1723 This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any
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a b s t r a c t Three new transition metal complexes of the type ML 2 (where M = Ni(II), Co(II) or Cu(II); HL = N 0 -[phenyl(pyridin-2-yl)methylidene]furan-2-carbohydrazide]) have been prepared by treating [NiCl 2 (PPh 3) 2 ], [CoCl 2 (PPh 3) 2 ] or [CuCl 2 (PPh 3) 2 ] with N 0 -[phenyl(pyridin-2-yl)methylidene]furan-2-car-bohydrazide derived from furoic acid hydrazide and 2-benzoyl pyridine wherein the hydrazone ligand (L) coordinated to the respective metal ions in 1:2 stoichiometry to mononuclear octahedral complex. The crystal structure of the complexes [NiL 2 ] (1), [CoL 2 ] (2) and [CuL 2 ] (3) solved using single crystals revealed a distorted octahedral geometry around the metal ion involving the coordination of an azome-thine nitrogen, a pyridine nitrogen and an enolic oxygen derived from deprotonation of the ligand. From the bioinorganic application point of view, a detailed work on the binding of the complexes 1, 2 and 3 with CT DNA as well as BSA was undertaken along with DNA cleavage. In vitro assay on the antioxidant activity of the above complexes and hydrazone ligand revealed that they possess significant antioxidant activity. However, among the newly synthesized hydrazone complexes, complex 3 having coordinated Cu 2+ ion in its molecular structure exhibited superior activity in all the biological studies in comparison with the other two complexes possessing nickel and cobalt ions with same ligand (L).
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The Schiff bases H2L, H2L, and H2L have been prepared from the reaction of 2-amino-4-chlorophenol with acetylacetone, benzoylacetone, and dibenzoylmethane, respectively. Organotin(IV) complexes [SnPh2(L)] (1), [SnPh2(L)] (2), [SnPh2(L)] (3), and [SnMe2(L)] (4) have been synthesized from the reaction of SnPh2Cl2 and SnMe2Cl2 with these Schiff bases. The synthesized complexes have been characterized by elemental analysis and FT-IR, H, C, and Sn NMR spectroscopy. Spectroscopic data suggest the Schiff bases are completely deprotonated and coordinated tridentate to tin via imine nitrogen and phenolic and enolic oxygen atoms; the coordination number of tin is five. Thermal decomposition of the complexes has been studied by thermogravimetry. The in vitro antibacterial activities of the Schiff bases and their complexes have been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. H2L, H2L, and all complexes exhibited good activities and have potential as drugs.
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A series of mononuclear organotin(IV) complexes of the types, R3SnL {R = C4H9 (1), C6H11 (2), CH3 (3) and C6H5 (4)}, R2SnClL {R = C4H9 (5), C2H5 (7) and CH3 (9)} and R2SnL2 {R = C4H9 (6), C2H5 (8) and CH3 (10)}, have been synthesized, where L = 4-(4-methoxyphenyl)piperazine-1-carbodithioate. The ligand-salt and the complexes have been characterized by Raman, FT-IR and multinuclear NMR (1H, 13C and 119Sn) spectroscopy and elemental microanalysis (CHNS). The spectroscopic data substantiate coordination of the ligands to the organotin moieties. The structures of complexes 4 and 6 have been determined by single-crystal X-ray diffraction and illustrate the asymmetric bidentate bonding of the ligand. The packing diagrams indicate O···H and π···H intermolecular interactions in complex 4 and intermolecular S2C···H interactions in complex 6, resulting in layer structures for both complexes. A subsequent antimicrobial study indicates that the compounds are active biologically and may well be the basis for a new class of fungicides.
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Three novel binuclear diorganotin(IV) derivatives formulated as (R2Sn)2L (where R = Me, Bu and Ph) of a new symmetrical adipodihyrazone ligand, 1,6-bis(5-hydroxy-3-methyl-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl)hexane-1,6-dione (H4L) derived from the Schiff base condensation of adipic acid dihydrazide and benzoylacetone in a 1:2 M ratio were synthesized. The micro-analysis and various spectroscopic techniques viz., infrared (IR), multinuclear (¹H, ¹³C and ¹¹⁹Sn) magnetic resonance (NMR) spectroscopy and electrospray ionization mass (ESMS) spectrometry were employed to establish the chelating mode of the dihyrazone ligand towards the diorganotin moieties [R2Sn(IV)]²⁺. The single crystal X-ray diffraction analysis of complex, (Me2Sn)2L reveals that it crystallizes in monoclinic space group ‘P 21/n’ and consists of crystallographically discrete molecules. The complex has been investigated to prefer a highly distorted trigonal-bipyramidal geometry (TBP) over the square-pyramidal geometry (SP) around each tin centre wherein the more electronegative enolic and benzoylic oxygen atoms of the ligand are aligned axially, and two carbon atoms of the methyl groups attached to the tin metal atom and the imine nitrogen atom of the ligand aligned themselves equatorially around the tin centre in a trigonal plane. Thermal decomposition patterns of the dimethyl- and diphenyltin(IV) derivatives in air were also investigated by TG, DTG and DTA techniques.
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A new hydrazide Shiff base ligand GHL1 (5-bromo-2-hydroxybezylidene)-3,4,5-trihydroxybenzohydrazide) was prepared by refluxing of trihydroxybenzhydrazide with an ethanolic of 5-bromo-2-hydroxybenzaldehyde. The ligand reacted with Ni(II), Cu(II), Zn(II) and Cd(II) (acetate salts). All the complexes were characterized by elemental analysis, molar conductivity, TGA, UV-Vis and FT-IR spectral studies. All the complexes have octahedral geometry except Ni(II) complex which has tetrahedral geometry. KEY WORDS: Hydrazone complexes, Schiff base ligand, Spectral studies Bull. Chem. Soc. Ethiop. 2012, 26(1), 95-101.DOI: http://dx.doi.org/10.4314/bcse.v26i1.10
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A series of metal complexes of Co(II), Ni(II), Cu(II) and Zn(II) with 2-amino benzoic acid thiophen-2-ylmethylene hydrazide (Habth) and 2-hydroxy benzoic acid thiophen-2-ylmethylene hydrazide (Hhbth) have been synthesized. The complexes were characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, electronic, IR, NMR, ESR spectra and thermal studies (TGA and DTA). Molecular structure of the Habth ligand was determined by single crystal X-ray diffraction technique. Habth acts as a monobasic bidentate ligand in all its complexes bonding through a deprotonated CO− and CN groups whereas, Hhbth acts as a monobasic bidentate in its Co(II) and Ni(II) complexes, bonding through a deprotonated CO− and CN groups and as monobasic tridentate in Cu(II) and Zn(II) complexes bonding through CO, CN and deprotonated (CO)− groups with the metal ion. Electronic spectra suggest a square planar geometry for Co(II), Ni(II) and Cu(II) complexes of Habth and Co(II) and Ni(II) complexes of Hhbth. However, the Cu(II) and Zn(II) complexes of Hhbth have octahedral geometry. The ESR spectra of Cu(II) complex of Hhbth in the solid state and in DMSO frozen solution show axial signals and suggest the presence of unpaired electron in dx2-y2dx2-y2 orbital of Cu(II). The Cu(II) complex of Habth in solid state shows isotropic signal, whereas, axial signal in DMSO frozen solution in the range of tetragonally distorted octahedral geometry due to interactions of DMSO molecules at axial positions. Thermal studies of some of the metal complexes show a multi-step decomposition pattern of bonded ligands in the complex.
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Complexes [Cu(2AcPh)Cl]·2H2O (1), [Cu(2AcpClPh)Cl]·2H2O (2), [Cu(2AcpNO2Ph)Cl] (3), [Cu(2BzPh)Cl] (4). [Cu(2BzpClPh)Cl] (5) and [Cu(2BzpNO2Ph)Cl] (6) were obtained with 2-acetylpyridine-phenylhydrazone (H2AcPh), 2-acetylpyridine-para-chloro-phenylhydrazone (H2AcpClPh), 2-acetylpyridine-para-nitro-phenylhydrazone (H2AcpNO2Ph), 2-benzoylpyridine-phenylhydrazone (H2BzPh), 2-benzoylpyridine-para-chloro-phenylhydrazone (H2BzpClPh) and 2-benzoylpyridine-para-nitro-phenylhydrazone (H2BzpNO2Ph). The hydrazones showed poor antibacterial effect against Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa but demonstrated significant antifungal activity against Candida albicans. Upon coordination to copper(II) the antibacterial and antifungal activities appreciably increased. H2AcpClPh, H2BzpClPh and their copper(II) complexes (2) and (5), respectively, were as active as fluconazole against C. albicans.
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The chemistry of chalcones has generated intensive scientific studies throughout the world. Especially interest has been focused on the synthesis and biodynamic activities of chalcones. The name “Chalcones” was given by Kostanecki and Tambor1. These compounds are also known as benzalacetophenone or benzylidene acetophenone. In chalcones, two aromatic rings are linked by an aliphatic three carbon chain. Chalcone bears a very good synthon so that variety of novel heterocycles with good pharmaceutical profile can be designed.
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The title compound, C15H12N2O2S, is a P21/c polymorph of a previously reported P21/n polymorph [Büyükgüngör et al. (2004 ▶). Acta Cryst. E60, o1414-o1416]. The dihedral angle between the benzo-thia-zole (r.m.s. deviation = 0.010 Å) and the benzene ring of 7.86 (6)° compares with 10.76 (10)° in the literature structure. The meth-oxy substituent is almost coplanar with the benzene ring to which it is attached [C-O-C-C torsion angle = 178.31 (14)°] and the conformation about the imine bond [1.287 (2) Å] is E. There is an intra-molecular O-H⋯N hydrogen bond and the hy-droxy O and thio-ether S atoms are syn. In the crystal, columns are formed along the b axis as centrosymmetric dimeric aggregates, mediated by C-H⋯O inter-actions and linked by π-π inter-actions between the thia-zole and benzene rings [centroid-to-centroid distance = 3.8256 (10) Å].
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Two binary copper(II) and nickel(II) complexes viz., [Cu(L)(HL)]NO 3.H2O (1) and [Ni(L)(HL)]NO3.H2O (2) of hydrazone Schiff base ligand (where L/HL = N'-[phenyl(pyridin-2- yl)methylidene]benzohydrazone) have been synthesized and characterized. Both the complexes (1) and (2) and ligand (HL) are structurally characterized using single crystal X-ray diffraction technique. They crystallize in monoclinic crystal system in the space group P21/n. The observed trends in spin-Hamiltonian parameters g∥>g⊥>2.03 indicates a dx 2-y2 ground state in complex (1). In the absorption spectra in 100% DMSO, complex (2) exhibits a d-d transition at ∼900 nm, which is assigned to ν1 band (3A2g→ 3T2g in octahedral parentage). Superoxide dismutase activities of both complexes reveal the dismutation of superoxide (O 2-).
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The ligand, N'-(phenyl-pyridin-2-yl-methylene)-thiophene-2-carboxylic acid hydrazide (Hpmtc) derived from thiophene-2-carboxylic acid hydrazide and 2-benzoyl pyridine, and its metal complexes with Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized. These compounds are characterized by elemental analyses, magnetic susceptibility measurements, IR, NMR and UV-Vis spectral studies. The molecular structures of Hpmtc and its Co(II) (1), Ni(II) (2), Cu(II) (3) and Zn(II) (4) complexes are finally determined by X-ray crystallography. Various spectral and single-crystal X-ray diffraction studies suggest that Hpmtc coordinates with metal ions as a monobasic tridentate ligand forming mononuclear distorted octahedral complexes of the type [M(pmtc)2]. The molecular structures of the complexes are stabilized by CH⋯N, CH⋯O intermolecular H-bonding, and CH⋯π and π⋯π interactions. The DNA binding experiment of the complexes 1, 3 and 4 by UV-Vis absorption, and EB-DNA displacement by fluorescence spectroscopy, reveal an intercalative mode of binding between CT-DNA (calf-thymus DNA) and the metal complexes. These complexes exhibit a moderate ability to cleave pBR322 plasmid DNA. A comparative bovine serum albumin (BSA) protein binding activity of the complexes 1, 3 and 4 has also been determined by UV-Vis absorption and fluorescence spectroscopy. The DNA binding and protein binding studies suggest that the complex 3 exhibits more effective binding activity (Kb=5.54×10(5) and Kq=1.26×10(6)M(-1), respectively) than complexes 1 and 4. However, the complex 1 shows better hydrolytic DNA cleavage activity compared to 3 and 4 complexes.
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A facile stepwise synthesis of 2, 5-disubstituted 1, 3, 4-oxadiazoles proceeding via oxidative cyclization of N-acylhydrazones is reported. The reaction is efficiently promoted by 2, 3-dichloro-5, 6-dicyano-1, 4- benzoquinone (DDQ) to afford the desired products mostly in high yields and in relatively short times. The final 1, 3, 4-oxadiazole derivatives are also synthesized directly from acid hydrazides and aldehydes in a one-pot procedure. The substrate scope and limitations of the reported transformation are discussed in detail.
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A series of new nickel(II) and copper(II) hydrazone complexes 1{14, containing a bidentate NO-donor hydrazone ligand, derived from 4-nitrobenzoylhydrazide and several aliphatic and aromatic aldehydes were synthesized, and their chemical structures were con�rmed by means of FT-IR, UV-Vis, 1H and 13C NMR, mass spectral data, conductance measurements, and elemental analyses. The spectral data of the newly synthesized complexes show the formation of a 1:2 [metal:ligand] ratio. The ligands and their complexes were also investigated for their possible in vitro antimicrobial activities against S. aureus, S. epidermidis, E. coli, K. pneumonia, P. aeruginosa, P. mirabilis, E. faecalis, and C. albicans. Among the fourteen new complexes synthesized, complex Cu(L4)2 (7) containing a direct aromatic moiety in the ligand (HL7) was found to be most active against selected test microorganisms.
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Reaction of tin tetrachloride with 2-pyridineformamide thiosemicarbazone (H2Am4DH) and its N(4)-methyl (H2Am4Me), N(4)-ethyl (H2Am4Et) and N(4)-phenyl (H2Am4Ph) derivatives gave [Sn(2Am4DH)Cl3] (1), [Sn(2Am4Me)Cl3] (2), [Sn(2Am4Et)Cl3] (3) and [Sn(2Am4Ph)Cl3] (4) as products, in which an anionic thiosemicarbazone coordinates to the metal centre along with three chloride ions. The crystal structures of 1 and 2 were determined. The thiosemicarbazones were moderately active against Candida albicans and Pseudomonas aeruginosa. Upon coordination to tin(IV) the antimicrobial activity of the thiosemicarbazones increases. The studied compounds proved to be toxic to Artemia salina, suggesting that they could present cytotoxic activity against solid tumors.
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A new series of diorganotin(IV) complexes has been synthesized by the reaction of R2SnCl2 (R = Me, Bu and Ph) with O,N,O-tridentate carbohydrazone ligand derived from carbohydrazide. Three diorganotin(IV) complexes of carbohydrazone-bis(salicylaldehyde) ligand [H 4CBS, (1)] with R2SnCl2 have been synthesized by refluxing in the presence of base in 1:2:1 molar ratio (metal:base:ligand). All the complexes (2-4) have been characterized by different physicochemical techniques like molar conductivity measurements, elemental analyses, UV-visible, IR and 1H NMR spectral studies. All complexes (2-4) are non electrolytic in nature. Among them, diphenyltin(IV) complex (4) has also been characterized by X-ray crystallography diffraction analyses. In the solid state, the carbohydrazone ligand (1) exists as the keto tautomer. But in solution in the presence of base and organotin(IV) chloride(s), it is converted to the enol tautomer and is coordinated to the tin atom in its deprotonated enolate form. X-ray crystallographic analysis shows that the diphenyltin(IV) complex, [Ph 2Sn(H2CBS)] (4), is five-coordinate and has a distorted trigonal-bipyramidal geometry with the ligand coordinated to the tin(IV) as a tridentate dinegative fashion through its phenolic-O, enolic-O and imine-N atoms. The general bond length order is: oxo < phenolato < enolato. The Sn-O (enolato) bond is longer than Sn-O (phenolato) bond by -0.095 Å and is identical with Sn-O (carboxylate) bond. The crystal of [Ph 2Sn(H2CBS)] (4) is triclinic with space group P-I with a = 8.514(2)Å, b = 12.505(3)Å, c = 12.794(4)Å, α = 105.169(4)°, β= 107.639(4)°, γ = 96.232(4)°, V = 1226.5(6) Å3, Z = 1 and Dcalc = 1.541 mg/m 3. The IR, UV and 1H NMR data are consistent with all the diorganotin(IV) derivatives having similar geometry.
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A series of mono- and dimethyltin(IV) complexes with N-salicylidene- and N-pyridoxylidene acylhydrazines have been prepared and characterized by IR, UV-vis, 1H NMR and mass spectral techniques. The X-ray crystal structure of monochloro-monomethyl [(N-salicylidene-p-methoxybenzoylhydrazinato)ONO(−2) ]tin (IV) methanol has been determined. In this complex the hydrazone dianion acts as a tridentate ligand and the tin(IV) is six-coordinated in a distorted octahedral geometry with the phenolic oxygen, azomethine nitrogen, amidate oxygen and methyl carbon occupying the equatorial plane while the chloride and methanol oxygen lie in the axial positions. The two molecules in the unit cell are connected by NHO bonds. The structure of both mono- and dimethyltin(IV) complexes in different solvents as well as the effect of solvents on the 1H NMR spectra of dimethyltin(IV) complexes are discussed.
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A chiral Schiff base N-(S)-2-(6-methoxylnaphthyl)-propanoyl-N′-(2-hydroxylbenzylidene)hydrazine (H2L) has been synthesized. Reaction of H2L with Cu(OAc)2·H2O led to the formation of a metal complex {[CuL]·H2O·2DMF}∞ (1). In complex 1, the potential dinegative tridentate L2− ligand acting as tetradentate bridging ligand coordinate to two metal ions so as to form a novel infinite metal–organic coordination chain structure. The enantiomerically pure ligand H2L presents two different sets of signals in the 1H NMR spectrum either in chloroform solution or in dimethylsulfoxide solution, showing the presence of both (E) and (Z) isomers. The X-ray structural investigations of H2L revealed that it is the fully extended E-configuration in the solid state.
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Four tridentate dibasic ONO donor hydrazone ligands derived from the condensation of benzoylhydrazine with either 2-hydroxyacetophenone or its para substituted derivatives (H2L1–4, general abbreviation H2L) have been used as primary ligands and 8-hydroxyquinoline (Hhq, a bidentate monobasic ON donor species) has been used as auxiliary ligand. The reaction of [VIVO(acac)2] with H2L in methanol followed by the addition of Hhq in equimolar ratio under aerobic condition afforded the mixed-ligand oxovanadium(V) complexes of the type [VVO(L)(hq)] (1–4) in excellent yield. The X-ray structure of the compound [VVO(L4)(hq)] (4) indicates that the H2L4 ligand is bonded with vanadium meridionally in a tridentate dinegative fashion through its deprotonated phenolic-O, deprotonated enolic-O and imine-N atoms. The V–O bond length order is: oxo
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In this paper, we report the synthesis and the characterization of a novel series of lanthanide (III) complexes with two potentially hexadentate ligands.The ligands contain a rigid phenanthroline moiety and two flexible hydrazonic arms with different donor atom sets (NNN′N′OO and NNN′N′N″N″, respectively for H2L1 (2,9-diformylphenanthroline)bis(benzoyl)hydrazone and H2L2 (2,9-diformylphenanthroline)bis(2-pyridyl)hydrazone).Both nitrate and acetate complexes of H2L1 with La, Eu, Gd, and Tb were prepared and fully characterized, and the X-ray crystal structure of the complex [Eu(HL1)(CH3 COO)2]·5H2O is presented.The stability constants of the equilibria Ln3++H2L1=[Ln(H2L1)]3+ and Ln3++(L1)2−=[Ln(L1)]+ (Ln=La(III), Eu(III), Gd(III), and Tb(III)) are determined by UV spectrophotometric titrations in DMSO at t=25 °C. The nitrate complexes of H2L2 with La, Eu, Gd and Tb were also synthesized, and the X-ray crystal structures of [La(H2L2)(NO3)2(H2O)](NO3), [Eu(H2L2)(NO3)2](NO3) and [Tb(H2 L2)(NO3)2](NO3) are discussed.
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A series of new diorganotin and triorganotin(IV) heterocyclicdicarboxylates [(nBu3Sn)2(2,5-pdc)]∞ (1), {[(2-FC6H4CH2)3Sn]2(2,5-pdc)}∞ (2), {[(2-ClC6H4CH2)3Sn]2(2,5-pdc)}∞ (3), {[(4-CNC6H4CH2)3Sn]2(2,5-pdc)}∞ (4), {[(4-ClC6H4CH2)3Sn]2(2,5-pdc)}∞ (5), [(Ph)2Sn(2,6-pdc)(H2O)]∞ (6), {[nBu3Sn(2,6-pdc)SnnBu3]2(H2O)2}·C2H3N (7) and {[Ph3Sn(2,3-pdz)SnPh3]2(H2O)} (8) have been obtained by reactions of diorganotin(IV) and triorganotin (IV) oxide with 2,6 or 2,5-H2pdc (pdc=pyridinedicarboxylate) or 2,3-H2pdz (pdz=pyrazinedicarboxylate). Complexes 1–8 were characterized by elemental, IR and NMR spectra analyses. The crystal and molecular structures of compounds 1, 6, 7 and 8 have been determined by X-ray single crystal diffraction. Compound 1 has 2D network structures. Compound 6 has 1D polymeric chain and 3D framework supramolecular structures due to the coordinated water molecules. Compound 7 has a monomeric structure, but the supramolecular structures are network.
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A series of organotin (IV) compounds of the type [R3SnL]2, R is Me (1), Bu (2), [R2SnL]2, R is Ph (3), Me (4), Bu (5), L is pyruvic acid thiophene-2-carboxylic hydrazone, and R2SnL, R is Me (6), Bu (7), Ph (8), L is salicylaldehyde thiophene-2-carboxylic hydrazone have been synthesized in 1:1 molar ratio. All compounds were characterized by elemental analysis, IR, 1H NMR, 13C NMR and 119Sn NMR spectra. The crystal structure of compounds 1, 3, 4, 8 have been determined by X-ray single crystal diffraction analyses, study found that the compounds 1 and 3 are rendered one-dimensional chain structure and the tin atoms are five-coordinated in a distorted trigonal-bipyramidal geometry. The compound 4 has a dimeric structure and the central tin atom is rendered seven-coordinate in a distorted pentagonal-bipyramid configuration. While the compound 8 is a monomer in which the tin atom adopts five-coordinated in distorted trigonal-bipyramidal geometry.
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A new diorganotin(IV) complex, Me2Sn[5-Br-(2-OC6H4CH=N–N=C(O)Ph)] (1) has been synthesised from dimethyltin(IV) dichloride and a Schiff base derived from 5-bromosalicylaldehyde and benzoyl hydrazide. The complex has been characterised by elemental analysis, and FT-IR and NMR spectroscopies. Molecular structure has been confirmed by single-crystal X-ray diffraction analysis. Complex 1 crystallises in triclinic system, space group P-1 (no. 2) with a=7.562(6), b=9.980(8), c=11.899(8) Å; α=81.08(6)°, β=72.71(5)°, γ=79.64(6)°; Z=2. The ligand N′-(5-bromo-2-hydroxybenzylidene)benzoylhydrazone (H2L) coordinates to the metal centre in enolate form via the phenolic O, imino N and enolic O atoms. The central tin atom is in distorted trigonal bipyramidal geometry with two oxygen atoms of the ligand in axial positions, while the imino nitrogen atom of the ligand and two methyl groups on tin occupy the equatorial sites.
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Bacteria have several attributes which make them attractive for use in bioassay procedures, and they are well suited for use as a primary biological monitoring system for detecting chemical toxicity. A chemical's toxicity to bacteria is normally measured in terms of inhibition of growth rate, oxygen consumption, ATP level, dehydrogenase activity, and colony formation on agar plate. This paper describes the assessment of chemical inhibition to the mixed bacterial populations by a modified agar plate technique and discusses the potential application of this method in other related areas. Refs.
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The Fusarium mycotoxins fumonisin B(1) (FB(1)) (1) and B(2) (FB(2)) (2), their hydrolysed analogues HFB(1) (3) and HFB(2) (4) and the recently discovered fumonisin derivatives N-palmitoyl-HFB(1) (5) and N-carboxymethyl-FB(1) (6) were compared for their toxicity in a short term bioassay using brine shrimp (Artemia salina). The brine shrimp were hatched in artificial sea water and exposed to the fumonisins in microwell plates with a mortality endpoint after 48 hours. LC(50) values were calculated after Probit transformation of the resulting data. Of the substances tested, fumonisin B(1) emerged to be the most toxic whereas its N-carboxymethyl analogue was 100-fold less effective. The hydrolysed fumonisins showed a four- to sixfold reduced toxicity compared to FB(1). N-Palmitoyl-HFB(1) had a higher LC(50) value than its precursor HFB(1). The brine shrimp assay proved to be a convenient and rapid system for toxicity assessment of this group of mycotoxins.
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In this study, the anti-termitic activities of 11 essential oils from three species of coniferous tree against Coptotermes formosanus Shiraki were investigated using direct contact application. Results demonstrated that at the dosage of 10 mg/g, the heartwood and sapwood essential oils of Calocedrus macrolepis var. formosana and Cryptomeria japonica and the leaf essential oil of Chamaecyparis obtusa var. formosana had 100% mortality after 5 d of test. Among the tested essential oils, the heartwood essential oil of C. macrolepis var. formosana killed all termites after 1 d of test, with an LC(50) value of 2.6 mg/g, exhibiting the strongest termiticidal property. The termiticidal effect of heartwood essential oil was due to its toxicity and its repellent action.
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Keeping in view the chemotherapeutic of the sulfa-drugs, Schiff base namely 2-thiophene carboxaldehyde-sulfametrole (HL) and its tri-positive and di-positive metal complexes have been synthesized and characterized by elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance, mass spectra, UV-vis and thermal analysis (TGA and DrTG). The low molar conductance values suggest the non-electrolytic nature of these complexes. IR spectra show that HL is coordinated to the metal ions in a tetradentate manner through hetero five-membered ring-S and azomethine-N, enolic sulfonamide-OH and thiadiazole-N, respectively. Zn(II), Cd(II) and UO2(II) complexes are found to be diamagnetic (as expected). The proposed general formulae of the prepared complexes are [M2X4(HL)(H2O)4] (where M=Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), X=Cl, [Fe2Cl6(HL)(H2O)2], [(FeSO4)2(HL)(H2O)4] and [(UO2)2(HL) (NO3)4].H2O. The thermal behaviour of these chelates shows that the hydrated complexes loss water of hydration in first step in case of uranium complexes followed loss coordinated water followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as DeltaE*, DeltaH*, DeltaS*, and DeltaG* are calculated from the DrTG curves using Coats-Redfern method. The antimicrobial activity of the obtained products was performed using Chloramphenicol and Grisofluvine as standards, indicate that in some cases metallation increase activity than the ligand.
Article
Five novel organotin(IV) derivatives have been synthesized by refluxing trimethyl, triethyl, tributyl, and triphenyl and tribenzyltin chloride with Schiff base derived from salicylaldehyde and adenine. These compounds were characterized by spectroscopic (IR, (1)H, (13)C, (119)Sn-NMR, (119m)Sn Mössbauer) techniques and elemental analysis. Based on these results, trigonal bipyramidal geometry is suggested. The synthesized compounds were also treated with various microorganisms and found to be active.
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