
Hassan KeypourBu-Ali Sina University · Inorganic Chemistry
Hassan Keypour
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Publications (237)
Expression of concern for ‘Schiff base Mn(iii) and Co(ii) complexes coated on Co nanoparticles: an efficient and recyclable magnetic nanocatalyst for H2O2 oxidation of sulfides to sulfoxides’ by Shokoufeh Ghahri Saremi et al., RSC Adv., 2018, 8, 3889–3898, https://doi.org/10.1039/C7RA11225D.
Expression of Concern for ‘Novel Schiff base Mn(iii) and Co(ii) complexes supported on Co nanoparticles: efficient and recyclable magnetic nanocatalysts for alcohol oxidation’ by Hassan Keypour et al., RSC Adv., 2016, 6, 77020–77029, https://doi.org/10.1039/C6RA15967B.
A new hexanuclear Zn(II) complex with the ligand 2,2’-(piperazine-1,4-diyl)bis(ethan-1-amine),
[L3Zn6(OH)6[ClO4]6·3MeOH·7H2O, was synthesized. The crystal structure of this complex showed that each Zn atom is in a distorted tetrahedral coordination environment, surrounded by two nitrogen atoms from each ligand and two hydroxide groups, each of whic...
C–C coupling reactions represent a fundamental synthetic methodology widely employed in academic and industrial settings. Herein, we present a report on developing and synthesizing a heterogeneous catalyst that is environmentally compatible and has recycling capabilities. Furthermore, the utilization of this catalyst for C–C coupling reactions was...
Herein, a new catalytic nanocomposite [Co(BDC-NH2)-Pd NPs] composed of a Co(BDC-NH2) MOF has been developed. The catalyst was prepared by modifying the synthesized porous Co(BDC-NH2) MOF with decorated Pd nanoparticles. This nanocatalyst was used as a heterogeneous catalyst in the reductive degradation of organic dyes Rhodamine B and methyl orange...
To synthesize new symmetrical macroacyclic Schiff base ligands (L1 and L2), polyamine (A) was condensed with 2-formylpyridine and salicylaldehyde. Furthermore, Ni(ClO4)2.6H2O and Zn(ClO4)2.6H2O in methanol were reacted with the ligands to prepare corresponding metal complexes. The cytotoxicity of the synthesized complexes against MCF-7 and A549 ade...
In this work, a modified electrode named Au/Au NPs-PPy/l-CYs/ZIF-8 was designed and built and simultaneously doped into electropolymerized polypyrrole (PPy) film using cyclic voltammetry (CV). Scanning Electron Microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and CV were used to characterize the composite films. The PPy-(ZIF-8) modif...
Three new metal complexes have been obtained from the reaction of a new polyamine (L) with Ni(II),
Cu(II), and Co(II) ions. The X-ray structural analysis of the Cu(II) complex shows that the copper atom is
in a very distorted square pyramidal environment, coordinated by five of the six nitrogen donor atoms
of the potentially hexadentate ligand. To...
Selective oxidation of active and inactive alcohol substrates and reduction of nitroarenes is a highly versatile conversion that remains a challenge in controlling functionality and adjustments in metal-organic frameworks (MOFs). On the other hand, it offers an attractive opportunity to expand their applications in designing the next generation of...
Two new 24- and 26-membered macrocycles (L1 and L2) have been prepared from condensation
of N 1-[2-(2-aminophenoxy)ethyl]-benzene-1,2-diamine (1), N 1-(3-(2-aminophenoxy) propyl)
benzene-1,2-diamine (2) and 2,6-diformyl-4-methyl phenol in methanol. The ligands were
characterized with various spectroscopic methods such as FT-IR, 1H and 13C NMR and E...
Three symmetrical macroacyclic Schiff base complexes were prepared from a ligand derived from the condensation reaction of 1,4-bis(2-aminophenyl)piperazine and salicylaldehyde (L) with Cu(ii), Ni(ii) and Co(ii) perchlorates. The ligand and the Schiff base complexes were characterized by elemental analyses, UV-vis, FT-IR and mass spectrometry, with...
An electrode composite containing a metal organic framework (Mn-MIL-100) was prepared by linkers including gold nanoparticles/polypyrrole and cysteine. The electrocatalytic application of this nanocomposite was evaluated via the oxidation of benzylic and aliphatic alcohols under open air conditions. Various active and inactive alcohol derivatives w...
In this study, the synthesis of a novel functionalized metal-organic-framework (MOF) [Cu(BDC-NH2)@Schiff-base-Pd(ii)] catalyst via post-synthetic modification of Cu(BDC-NH2) is reported. The targeted complex was prepared by chemically attaching N,N'-bis(5-formylpyrrol-2-ylmethyl) homopiperazine via a Schiff base reaction followed by complexation wi...
The biological activities of 1,4 bis(o-aminobenzyl)-1,4diazacycloheptane (L) and the copper(II) and nickel(II) complexes, [CuL](ClO4)2 and [Ni(L)(NCMe)2](ClO4)2. NCMe, were investigated. The X-ray structural analysis of the latter complex shows that the nickel(II) ion is in a slightly distorted octahedral coordination environment coordinated by fou...
Reducing nitroarenes to their amines is among the common and vital reactions with remarkable industrial significance. This study describes an eco-friendly recyclable catalyst for reducing nitroarene. For this purpose, a new strategy was designed to synthesize a new amide-based COF through the reaction between 1,4‑diaminobenzene and trimesic acid (B...
A Pd(II) Schiff base complex as an efficient and highly heterogeneous catalyst was developed by immobilization of a palladium complex on the surface of modified Fe3O4 magnetite nanoparticles. These surface-modified nanoparticles were characterized using various techniques such asSEM, TEM, XRD, FT-IR, EDX and VSM. The palladium catalyst exhibited ef...
We prepared a novel palladium (Pd) catalyst by loading palladium chloride onto novel functionalized multi-wall carbon nanotubes (MWCNTs). The Pd( ii )/MWCNT complex efficiently and selectively catalyzed large-scale synthesis of target molecules with high yield and large turnover numbers.
Schiff base ligands can be considered key to designing fluorescent chemosensors due to their chromogenic properties. Here, we study this view and demonstrate that there is a remarkable fluorescence enhancement upon Al³⁺ addition to a new macroacyclic Schiff base ligand (H2L) compared with 15 different metal ions, while the limit of detection (LOD)...
Three symmetrical macroacyclic Schiff base complexes were prepared from a ligand derived from the condensation reaction of 1,4-bis(2-Aminophenyl)piperazine and salicylaldehyde (L) with Cu(II), Ni(II) and Co(II) perchlorates. The ligand and the Schiff base complexes were characterized by elemental analyses, FT-IR and mass spectrometry, with the stru...
A new ligand (L) containing two nitro phenyl rings as side chains was synthesized. The reaction of this ligand with copper(II) and zinc(II) metal ions gave complexes with different coordination environments. The free ligand and the metal complexes were characterized using a number of spectroscopic methods. The crystal structure of [ZnLBr]ClO4 showe...
Herein, we aim at preparing 15-membered-ring symmetrical pentaaza macrocyclic Schiff base complexes using a template approach, based on the condensation reaction of an amine containing piperazine moiety, 2,2-(piperazine1,4-diyl)dianiline, and 2,6-diacetylpyridine in 1:1 mol ratio while Cd(II), Mn(II) and Zn(II) metal ions are present. Moreover, FT-...
A number of binuclear and mononuclear macroacyclic Schiff base complexes containing piperazine moieties were synthesized. The binuclear complexes (M2L1) characterized by elemental analysis, IR and, also Ni(II) complex by a X-ray single crystal structural analysis. In this case, X-ray showed that each nickel atom is in a mer-N3O3 octahedral coordina...
A new dialdehyde N, N'-bis(5-formylpyrrol-2-ylmethyl) homopiperazine (A) was synthesized by the Mannich reaction of pyrrole 2-carbaldehyde, formaldehyde and homopiperazine in the presence of hydrochloric acid. From the direct reaction of A with 1,3-diaminopropane or 1,4- diaminobutane two new macrocyclic Schiff base ligands were obtained, L¹ and L²...
A new platinum Schiff base complex, [C17H28N4OPt]Cl2 (1) was prepared from the condensation of a polyamine containing piperazine moiety, (1,4-bis(3-aminopropyl)piperazine) and 2-hydroxy-benzaldehyde (H2L), in the presence of Pt²⁺ ion and examined by mass, FT-IR, elemental analysis ¹H-NMR and ¹³C-NMR. The structure of the metal complex has been conf...
In this research, synthesis and characterization of a novel Schiff base Cu (II) complex immobilized on Fe3O4@SiO2 nanoparticles are reported. Then, the catalytic activity of these nanoparticles as magnetic recyclable nanocatalyst was explored for the one-pot three-component synthesis of quinolin-5-one, chromene-3-carbonitrile and phthalazine-5,10-d...
Three new Zn(II), Cd(II) and Mn(II) macrocyclic Schiff base complexes have been prepared via the Mn(II), Cd(II), and Zn(II) templated [1+1] cyclo condensation of phtalaldehyde with an asymmetrical diamine, 2-((4-(2-((2-amino benzyl)amino)ethyl)piperazine-1-yl)methyl)aniline. The complexes have been characterized by elemental analysis, IR, ESI-MS, a...
In this article, the synthesis of a novel and highly efficient recyclable and reusable heterogeneous nanocatalyst has been reported via the functionalizing of the Fe3O4‐magnetized graphene oxide nanosheets with the N6‐Schiff base Cu (II) complex (GO/Fe3O4@SPNC). The structure of this novel nanocatalyst was determined by different analytical techniq...
A hexadentate, asymmetric tripodal scorpionate type ligand, [[N1-Pyridin-2-ylmethyl-N1-[2-(4-pyridine-2-ylmethyl-piperazine-1-yl)-ethyl]-ethane-1,2-diamine]] (L) has been prepared. To form this ligand, the direct reductive amination of a carbonyl compound by NaBH4 was used for the synthesis of tertiary amine. The complexes [MnL])ClO4(2, [CdL])ClO4(...
Generation of the positive CN ion and the corresponding direct cyanation are both extremely important for cyanation of aromatic compounds. Hereby, we would like to report the simultaneous use of the new Pd nano-catalyst as well as the three types of the N-arylsulfonyl cyanamides (A, B and C) as potent reagents for the in situ generation of the posi...
Macroayclic complexes of Ni(II), Cu(II) and Co(II) were synthesized via the reaction of 1,4-bis(o-aminobenzyl)-1,4-diazacycloheptane (L) with the respective metal salts. The polyamine ligand and the corresponding complexes were characterized by mass spectrometry, elemental analysis and FT-IR and for [CuL](ClO4)2(2), by a single crystal X-ray struct...
Recent studies about innovations in GO/N ‐Ligand‐Cu Nano‐Composites have been done. Graphene‐Oxide is improved with N ¹,N ³‐bis (pyridin‐2‐ylmethyl)propane‐1,3‐diamine and after that is matched with copper (Cu). The chemical composition and the structure of the catalyst were analyzed by TGA/DTG, EDX, XRD, FT‐IR, TEM, and SEM. The results demonstrat...
In this research study we designed and synthesized CoII(macrocyclic Schiff base ligand containing 1,4‐diazepane) immobilized on Fe3O4 nanoparticles as a novel, recyclable, and heterogeneous catalyst. The nanomaterial was fully characterized using various techniques such as Fourier‐transform infrared spectroscopy, scanning electron microscopy, trans...
Three macroacyclic Schiff base complexes have been obtained by the reaction of a previously known Schiff base ligand, 2-((Z)-(2-((4-((Z)-2-((Z)-2-hydroxy-3-methoxybenzylideneamino)benzyl)piperazin-1-yl)methyl)phenylimino)methyl)-6-methoxyphenol (H2L), and Mn(II), Zn(II) and Cd(II) ions in mixture of ethanol and methanol solvents. The resultant comp...
The preparation of Manganese(III), Zinc(II) and Platinum(II) macroacyclic complexes drived from a previously known Schiff base ligand (H2L) and corresponding metal ions is described. While manganese and zinc formed complexes with the ligand, the reaction of K2PtCl4 resulted in hydrolysis of the ligand and the formation of the Pt(II) complex with th...
By the reaction of 1-Fluoro-2-nitrobenzene with homopiperazine, the new polyamine 2,2′-(1,4 -diazepane -1,4-diyl)dianiline (A) was prepared. The N4O2 Schiff base ligands were synthesized from condensation of polyamine A with 2-hydroxybenzaldehyde (H2L¹) or 2‑hydroxy-3-methoxybenzaldehyde (H2L²). Four macroacyclic Schiff-base complexes were obtained...
The aim of the present research is to develop a novel nano-magnetic catalyst based on Co complex. EDX analysis showed that 0.08 mmol Co is loaded per g of the catalyst. The characterization of the prepared catalyst was done according to the Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), field emission s...
A symmetrical macroacyclic Schiff base ligand, L, has been prepared from the condensation of 2-((4-(2-aminobenzyl)-1,4-diazepan-1-yl)methyl) benzenamine (A) with 2-formylpyridine. Its copper complex was synthesized by the reaction of ligand with Cu(ClO4)2·6H2O in methanol. The characterization of the product by elemental analyses, IR, EI–MS, ¹H and...
Two potentially N6O2 macroacyclic Schiff base ligands (H2L¹ and H2L²) were derived from the condensation of a new polyamine, 2,2′-(4,4′-(propane-1,3-diyl)bis(piperazine-4,1-diyl))diethanamine (A), with 2-Hydroxy- benzaldehyde or 2-hydroxy-3-methoxybenzaldhyde respectively. In the presence of appropriate metal ions, six manganese (II), zinc (II) and...
In this paper, a new symmetrical, potentially hexadentate N4O2, macroacyclic Schiff base ligand (H2L) was derived from the condensation of a polyamine, 2,2′-((1,4-diazepane-1,4-diyl)bis(methylene))dianiline (A), with 2-hydroxybenzaldehyde. Three Schiff base complexes were prepared by direct reaction of H2L with Cu(II), Zn(II) and Co(II) ions in equ...
A novel Cu (II) Schiff‐base complex immobilized on core‐shell magnetic Fe3O4 nanoparticles (Fe3O4@SPNC) was successfully designed and synthesized. The structural features of these nanoparticles were studied and confirmed by using various techniques including FT‐IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (T...
In this work, two new symmetrical, potentially N6O2 coordinating, macroacyclic Schiff base ligands (H2L¹ and H2L²) were derived from the condensation of a newly synthesized polyamine, 2,2′-(ethane-1,2-diylbis(piperazine-4,1-diyl))bis(ethan-1-amine) (A), with 2-hydroxybenzaldehyde and 2-hydroxy-3-methoxybenzaldhyde respectively. Six macroacylic Schi...
Two new symmetrical macroacyclic Schiff base ligands, L ¹ and H 2 L ² have been prepared from the condensation of 2-((4-(2-aminobenzyl)-1,4-diazepan-1-yl)methyl) benzenamine (A) with 2-formylpyridine and 2-hydroxy-3-methoxybenzaldehyde, respectively. Metal complexes were synthesized by the reaction of the ligands with Ni(ClO 4 ) 2 ·6H 2 O, Cu(ClO 4...
Here we report a number of novel macrocyclic Schiff base complexes with a homopiperazine skeleton. These symmetrical pentaaza macrocyclic Schiff base complexes were prepared via a template approach, based on the condensation reaction of an amine containing homopiperazine moiety and 2,6-diacetylpyridine or 2,6-pyridine dicarboxaldehyde in 1:1 mol ra...
A molybdenum complex was immobilized on Schiff-base-modified magnetic and non-magnetic particles by covalent linkage. The characterizations of the obtained materials were carried out by means of TG–DTG, SEM, TEM, VSM, XPS, IR, and Raman microprobe techniques. All of them exhibited efficient activities in the oxidation of sulfides to sulfoxides by u...
In order to investigate the stoichiometry and stability of a
Li+ complex with new heptadentate (N7) macrocyclic Schiff base Schiff
base having two pyridyl units as pendant arms (MSb) in Acetonitrile and
Methanol mixture (50:50), Lithium-7 NMR spectroscopy was employed. A
competitive 7Li NMR method was also used to probe the complexation of
Li+, Na+...
The Fe3O4 magnetic nano-particles were prepared, coated with tetraethyl orthosilicate (TEOS), functionalized with 3-chloropropyltrimethoxysilane (CPTMS), further functionalized with 2,2′-(piperazine-1,4-diylbis(methylene) dianiline (PDMD) and the corresponding Pd complex synthesized as a novel nano-magnetic heterogeneous catalyst (Fe3O4@SiO2@[email...
The synthesis of two known unsymmetrical N-capped tripodal amines, 3-((2-aminoethyl)(pyridine-2-ylmethyl)amino)propane-1-ol (3) and 3-((3-aminopropyl)(pyridine-2-ylmethyl)amino)propane-1-ol (4) is reported. They feature a longer 3-hydroxypropyl arm than in previously employed analogues (2-hydroxyethyl and ethylamino arms or 2-hydroxyethyl and propy...
Trigonal-prismatic structures among different transition metal complexes according to the Cambridge Structural Database (CSD) are rare. The number of trigonal prisms throughout the transition-metal series is less than 1% of all six-coordinate metal centers and only 0.4% of cobalt complexes. Herein we report a novel macroacyclic Schiff base complexe...
In this paper, an effective and selective heterogeneous catalyst was produced by immobilization of manganese and cobalt Schiff base-complexes on Co magnetite nanoparticles (MNP). The catalysts Co@SiO2[(EtO)3Si–L³]/M (M = Mn(III) and Co(II)) were synthesized using Co@SiO2 core–shell nanoparticles and amino-functionalized Co@SiO2. The Schiff base lig...
The new Cd(II) macrocyclic Schiff-base complexes were prepared via the metal templated [1 + 1] cyclocondensation of 2,2'-(piperazine-1,4-diylbis (methylene))dianiline (A) and 2,6-pyridinedicarbaldehyde or 2,6-diacetylpyridine. The products were characterized by elemental analysis, mass spectrometry and spectroscopic methods such as: FT-IR, ¹H and ¹...
Two macrocyclic Schiff base ligands (L¹, L²) and their related reduced forms (L³ and L⁴) have been prepared. In the presence of nickel(II) perchlorate in methanol, the reinforced macrobicyclic salts containing hexahydropyrimidine cation moiety have been developed. Here, it seems that Ni(II) perchlorate acts as oxidizing agent converting methanol to...
In this study, a PVC membrane electrode modified with a Cd Schiff base complex was constructed as a novel, sensitive and selective structured carrier for checking trace amounts of mefenamic acid in real samples. A novel macrocyclic Schiff base complex ([CdL²Cl]ClO4·2H2O) was synthesized via the Cd(II) templated [1 + 1] cyclocondensation of 2,9-dica...
The synthesis of two unsymmetrical N-capped tripodal amines, 2-((4-aminobutyl)(pyridin-2-ylmethyl)amino)ethanol (3) and 3-((2-aminoethyl)(pyridin-2-ylmethyl)amino)propan-1-ol (4) is reported for the synthesis of new tripodal Ni complexes. They feature a longer, 3-hydroxypropyl or butylamino arm than that in the analogues previously employed for syn...
Two new Schiff base ligands, H2L¹ and H2L², have been prepared from the condensation of 2-hydroxybenzaldehyde or 2-hydroxy-3-methoxybenzaldehyde with 2,2'-(piperazine-1,4-diylbis (methylene))dianiline (A¹), respectively. In the presence of appropriate metal ions and in methanolic/ethanolic solution four Cobalt (III) and Copper (II) macroacyclic Sch...
The new diamine 2,2'-(piperazine-1,4-diylbis(methylene))dianiline (A¹) was synthesized by reaction of 2-nitrobenzylchloride and piperazine. Its corresponding Mn(II) and Zn(II) macrocyclic Schiff-base complexes were prepared via the metal templated [1+1] cyclocondensation of this diamine and 2,6-diacetylpyridine or 2,6- pyridinedicarbaldehyde. The d...
A copper catalyst has been explored as an efficient and recyclable catalyst to effect Sonogashira and Suzuki cross-coupling reactions. After modification of 2-(((piperazin-1-ylmethyl)imino)methyl)phenol (PP) on the surface of amorphous silica-coated iron oxide (Fe3O4@SiO2@Cl) magnetic core–shell nanocomposite, copper(II) chloride was employed to sy...
The reaction of 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine (bptz) with the respective cadmium halides results in the formation of tetranuclear [Cd4(bptz)2(H2O)2(μ3-Cl)2(μ-Cl)2Cl4] (1), coordination polymer {[Cd(μ-bptz)Br2]·DMSO}n (2) and mononuclear [Cd(bptz)2I2] (3). To interpret the UV–vis spectra of the compounds measured in the solution phase and als...
A new asymmetrical tripodal amine, [H3L2]Br3 containing morpholine moiety was
prepared from reacting of one equivalent of N-(3-aminopropyl)morpholine and two equivalents
of tosylaziridine, followed by detosylation with HBr/CH3COOH. The products were characterized
by various spectroscopic methods such as FAB-MS, elemental analysis, 1H and 13C NMR sp...
In this study, a new glassy carbon electrode chemically modified with multi-walled carbon nanotubes (MWCNTs) and core-shell structured Fe3O4@[(EtO)3Si–L] was constructed and used for the sensitive and selective electrochemical determination of trace amounts of citalopram (CT). New Schiff base functionalized magnetic Fe3O4 nanoparticle was prepared...
In this study, efficient and highly selective heterogeneous catalysts were developed by immobilization of manganese and cobalt Schiff base complexes on Co magnetite nanoparticles (MNPs). Firstly, [email protected]2 core-shell nanoparticles were synthesized through a one-pot reaction. Secondly, the [email protected]2 was amino-functionalized using 3...
A novel and task-specific nano-magnetic Schiff base ligand with phosphate spacer using 2-aminoethyl dihydrogen phosphate instead of usual coating agents, i.e. tetraethoxysilane and 3-aminopropyltriethoxysilane, for coating of nano-magnetic Fe3O4 is introduced. The nano-magnetic Schiff base ligand with phosphate spacer as a novel catalyst was synthe...
A Pd(II) Schiff base complex as an efficient and highly heterogeneous catalyst was developed by immobilization of a palladium complex on the surface of modified Fe3O4 magnetite nanoparticles. These surface-modified nanoparticles were characterized using various techniques such as transmission electron microscopy, X-ray diffraction, thermogravimetri...
Three new dinuclear copper complexes were synthesized via condensation reaction of three new unsymmetrical N-capped tripodal amines and 2,6-diformyl-4-methylphenol, in the presence of copper(II) perchlorate. The solid-state structure of the dinuclear complex, [Cu2L1](ClO4)2, has been determined by X-ray crystallography, showing that the CuII center...
A new macrocyclic Schiff base ligand, L, was synthesized by condensation reaction of 1,4-bis(2-formylphenyl)homopiperazine and 1,4-diaminobutane in acetonitrile. The Schiff base ligand was characterized by using elemental analyses, FT-IR, 1 H, 13 C NMR and mass spectroscopic techniques. The metal (II) complexes [ML], were synthesized from the react...
In this study fullerene functionalized using oleum (H2SO4 center dot SO3), followed by the hydrolysis of the intermediate cyclosulfated fullerene as well as an oxidizing agent was employed to functionalize the fullerenes. Ruthenium was then added by the impregnation method or deposited on the functionalized fullerene. Subsequent to this step, Respo...
Two new symmetrical Mn(II) and Cd(II) pentaaza macrocyclic Schiff base complexes were prepared via templated [1 + 1] cyclocondensation of 2,6 diacetylpyridine and an amine containing homopiperazine moiety in the presence of related metal ions. These complexes have been characterized by elemental analysis, IR spectra, EI-MS, conductivity measurement...