Ari Lehtonen

• PhD, Docent
• Lecturer at University of Turku

Redox non-innocent ligands react with metal precursors to form complexes where the oxidation states of the ligand and thus the metal atom cannot be easily defined. A well-known example of such ligands is bis(o-aminophenol) N,N′-bis(3,5-di-tertbutyl-2-hydroxy-phenyl)-1,2-phenylenediamine, previously developed by the Wieghardt group, which has a pote...

The use of dioxidomolybdenum(VI) and-tungsten(VI) complexes supported by a variety of structurally different tri-and tetradentate aminobisphenolato ligands as pre-catalysts in the epoxidation of alkenes is well established. However, under the widely used standard 1 mol-% catalyst loadings these types of complexes generally show modest activity only...

The design of molecular containers capable of selectively binding specific guest molecules presents an interesting synthetic challenge in supramolecular chemistry. Here, we report the synthesis and structure of a coordination cage assembled from Cu3I4⁻ clusters and tripodal cationic N‐donor ligands. Owing to the localized permanent charges in the l...

The design of molecular containers capable of selective binding of specific guest molecules presents an interesting synthetic challenge in supramolecular chemistry. Here, we report the synthesis and structure of a coordination cage assembled from Cu3I4– clusters and tripodal cationic N-donor ligands. Owing to the localized permanent charges in the...

Molecular molybdenum complexes with sulfur donor ligands are generally studied as soluble model compounds for molybdenum enzymes essential for life. The dioxidomolybdenum(VI) complex with tetradentate aminobisphenolate ligand undergoes a reaction with thionation reagent P2S5 or its organic derivative, Lawesson’s reagent, to yield stable Mo(IV) amin...

An amine bisphenol ligand with an ammonium iodide group in the pendant arm (H2L) reacts with V, Mo and U oxometal precursors to form oxovanadium(V), dioxomolybdenum(VI) and dioxouranium(VI) species, respectively. In methanol solutions, vanadium(V) and molybdenum(VI) form 1:1 complexes [VO(OMe)(L)]I•2MeOH and [MoO2(L)(H2O)]I•2MeOH, where the cationi...

We report here the syntheses of a diamagnetic Fe complex [Fe(HL)2] (1), prepared by reacting a redox non-innocent ligand precursor N,N'-bis(3,5-di-tert-butyl-2-hydroxy-phenyl)-1,2-phenylenediamine (H4L) with FeCl3, and its phenoxazine derivative [Fe(L')2] (2), which was obtained via intra-ligand cyclisation of the parent complex. Magnetic measureme...

A series of new cationic dioxidomolybdenum(VI) complexes [MoO2(Lⁿ)]PF6 (2-5) with the tripodal tetradentate pyridyl aminophenolate ligands HL²-HL⁵ have been synthesized and characterized. Ligands HL²-HL⁴ carry substituents in the 4-position of the phenolate ring, viz. Cl, Br and NO2, respectively, whereas the ligand HL⁵, N-(2-hydroxy-3,5-di-tert-bu...

Six known aminophenolate vanadium complexes V1–V6 were examined in 3,5-di-tert-butylcatechol (1, 3,5-DTBC) oxidation. From the complexes V1–V5 have been previously shown to demonstrate catechol oxidase-like (catecholase) behavior, catalytically oxidizing 1 to 3,5-di-tert-butyl-1,2-benzoquinone (2, 3,5-DTBQ). A critical re-evaluation of V1–V5, inclu...

Oxidovanadium complexes with organic ligands are well known to have cytotoxic or differentiating capabilities against a range of cancer cell types. Their limited use in clinical testing though has resulted largely from uncertainties about the long-term toxicities of such complexes, due in part to the speciation to vanadate ions in the circulation....

New soluble and intensely near-IR-absorbing transition metal (Ti, Zr, V, Ni) complexes were synthesized using a redox non-innocent N,N’-bis(3,5-di-tertbutyl-2-hydroxy-phenyl) -1,2-phenylenediamine (H4L) as a ligand precursor. In all the complexes, ([Ti(Lox)2, [Zr(Lox)2], [V(Lsq1)(HLox)] and [Ni(HLox)2], two organic molecules coordinate to the metal...

A series of bioinspired dioxidomolybdenum(vi), dioxidotungsten(vi) and oxidovanadium(v) complexes [MoO2(H2LSaltris)], [WO2(H2LSaltris)] and [VO(HLSaltris)]2 were prepared by the reaction of a hydroxyl-rich Schiff base proligand N-(1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl)-3,5-di-tert-butylsalicylaldimine (H4LSaltris) with metal precursors in meth...

Bench top stable transition metal (M = Co, Ni, Cu) complexes with a non-innocent ortho-aminophenol derivative were synthesized by the reaction of metal(II)acetates with a ligand precursor in 2:1 ratio. The solid-state structures reveal the formation of neutral molecular complexes with square planar coordination geometries. The Co(II) and Cu(II) com...

Reaction of [MoO2Cl2(dmso)2] with the tetradentate O2N2 donor ligand papy [H2papy = N-(2-hydroxybenzyl)-N-(2-picolyl)glycine] leads to formation of the dioxomolybdenum(VI) complex [MoO2(papy)] (1) as a mixture of cis and trans isomers. Recrystallization from methanol furnishes solid cis-1, whereas the use of a dichloromethane-hexane mixture allows...

L-proline was used to prepare chiral, tridentate amino acid phenol proligands H 2 L 1–4 . These proligands react with vanadium precursors VO(acac) 2 , VOSO 4 ∙5H 2 O and VO(OPr) 3 in methanol to form the corresponding oxidoalkoxidovanadium(V) complexes 1–4. The complexes crystallize from methanol, and are octahedrally coordinated with a general for...

The reactions between [VO(acac)2] (acac– = acetylacetonate) and the tripodal amino bisphenols 6,6′-(((2-morpholinoethyl)azanediyl)bis(methylene))bis(2,4-di-tert-butylphenol) (H2L¹) and 6,6′-(((thiophen-2-ylmethyl)azanediyl)bis(methylene))bis(2,4-di-tert-butylphenol) (H2L²) as well as the tetradentate amino phenol 2,2′-((3,5-di-tert-butyl-2-hydroxyb...

Reaction of the tridentate aminoalcohol phenol ligands 2,4-di-tert-butyl-6-(((2 hydroxyethyl)(methyl)amino)methyl)phenol (H2L¹) and 2,4-di-tert-butyl-6-(((1-hydroxybutan-2-yl)amino)methyl)phenol (H2L²) with [MoO2(acac)2] in methanol solutions resulted in the formation of [MoO2(L¹)(MeOH)] (1) and [MoO2(L²)(MeOH)] (3), respectively. In contrast, the...

[W(N2O2)(HN2O2)] (H4N2O2 = N,N′-bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,2-phenylenediamine) with a noninnocent ligand was formed by reaction of the alkoxide precursor [W(eg)3] (eg = the 1,2-ethanediolate dianion) with two equivalents of ligand. The phenol groups on one of the ligands are completely deprotonated and the ligand coordinates in a tetr...

In this contribution, we report convenient synthetic approaches for obtaining ¹⁶O/¹⁸O‐enriched dioxidometalVI complexes, MO2(L) (W, Mo), with a linear, tetradentate amine phenolate ligand N,N′‐dimethyl‐N,N′‐bis(2‐hydroxy‐3,5‐dimethylbenzyl)ethylenediamine (H2L) and describe their characterization by IR and Raman spectroscopy complemented by DFT com...

Air-stable oxidovanadium(V) complexes with tetradentate amine bisphenolate ligands were made by the reaction of VOSO4·xH2O and ligand precursors in MeOH solutions. Isolated compounds were studied as catechol oxidase models as well as catalysts for epoxidation and sulfoxidation reactions. All compounds can catalyse such oxidation reactions without n...

Sixteen molybdenum and tungsten complexes with tripodal or linear tetradentate amino bisphenol ligands were studied as catalysts for the epoxidation of cis-cyclooctene, 1-octene, styrene, limonene and α-terpineol. These complexes can be divided into different categories upon key features, i.e. central metal (Mo vs. W), side-arm donor (O vs. N), hyb...

The new aminoalcohol phenol 2,4-di-tert-butyl-6-(((2-hydroxy-2-phenylethyl)amino)methyl)phenol (H2L) was prepared by a facile solvent-free synthesis and used as a tridentate ligand for new cis-dioxomolybdenum(vi)(L) complexes. In the presence of a coordinating solvent (DMSO, MeOH, pyridine), the complexes crystallise as monomeric solvent adducts wh...

The molybdenum(VI) and tungsten(VI) complexes [MO2(L)] (M= Mo (1), W (2), H2L = bis(2-hydroxy-3,5-di-tert-butybenzyl)morpholinylethylamine)) were synthesized and the complexes were used to catalyse oxotransfer reactions, viz. sulfoxidation, epoxidation and benzoin oxidation. For comparison, the same reactions were catalysed using the known complexe...

Low-cost metallate salts Na2MO4·2H2O (M = molybdenum, tungsten) react with a tridentate amine bisphenol bis(2-hydroxy-3-tert-butyl-5-methylbenzyl)methylamine (H2ONOtBu) under ambient conditions in acidic methanol solutions. The reactions lead to the formation of isostructural dioxo complexes [MO2(ONOtBu)(MeOH)]·MeOH in convenient yields. Spectral d...

Dioxotungsten(VI) complexes with tetradentate amino bisphenolates were converted into the corresponding Cs-symmetric amino bisphenolate disulphido complexes by a reaction with either Lawesson’s reagent or P2S5. Further reaction with diethyl acetylenedicarboxylate leads to the formation of diamagnetic tungsten(IV) dithiolene compounds. The syntheses...

The synthesis of four molybdenum and tungsten complexes bearing tetradentate tripodal amino bisphenolate ligands with either hydroxyethylene (1a) or hydroxyglycolene (1b) substituents is reported. The molybdenum dioxo complexes [MoO2L] (L = 2a, 2b) and tungsten complexes [WO2L] (3a, 3b) were synthesized using [MoO2(acac)2] and [W(eg)3] (eg = 1,2-et...

The reaction of VO(acac)2 (acac(-) = acetyl acetonate) with tripodal glycine bisphenol H3L(1) under an ambient atmosphere yields a hexacoordinated vanadium(iv) complex [V(acac)(L(1))] (). The corresponding reactions with tripodal 2-propanolamine bisphenol H3L(2) and potentially pentadentate ethoxyethanolamine bisphenol H3L(3) lead to the oxidation...

The oxomolybdenum(VI) complex [MoOCl(L)] with a tetradentate glycine bisphenol ligand (H3L) was prepared by reaction of [MoO2Cl2(DMSO)2] with a ligand precursor in hot toluene. The product was isolated in moderate yield as separable cis and trans isomers along with the third minor component, [MoO2(HL)]. The solid-state structure of trans-[MoOCl(L)]...

The syntheses, crystallographic structures, magnetic properties, and theoretical studies of two heptacoordinated molybdenum complexes with N,N'-bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,2-phenylenediamine (H4N2O2) are reported. A formally molybdenum(VI) complex [Mo(N2O2)Cl2(dmf)] (1) was synthesized by the reaction between [MoO2Cl2(dmf)2] and H4N2O2...

MoVI complexes with novel ditopic diaminotetraphenol ligands have been prepared by using a one-pot procedure in methanol or DMSO with [MoO2(acac)2] (acac = acetylacetonate) as the molybdenum source. The complexes were characterised with X-ray diffraction, NMR spectroscopic studies, elemental analysis and IR spectroscopy. In the solid state, the com...

Oxidomolybdenum(VI) complex [MoOCl(Ln)] with a tetradentate O3N-type aminoalc. bis(phenol) was prepd. as two separable isomers. These complexes can catalyze the epoxidn. of cis-cyclooctene and sulfoxidn. of tolyl Me sulfide as well as the oxo-transfer reaction between PPh3 and DMSO.

Aminobisphenols with side-arm donors are versatile tetradentate ligands that effectively coordinate to the metal ions in a tripodal fashion. Most of the metal ions form electrically neutral isolable complexes with aminobisphenolates with different side chains. However, some anionic complexes and zwitterions are also described. The coordination geo...

Tungsten(VI) complexes of the type [W(NPh)Cl3(L)] (L=chelating phenolate) were studied as catalyst precursors for ROMP of 2-norbornene, dicyclopentadiene and 5-vinyl-2-norbornene. These compounds form active catalysts when treated by ethyl magnesium bromide. Moreover, polymerisations can be run under ambient atmosphere without complicated inert atm...

The reactions between [VO(acac)2] (acac– = acetylacetonate ion) or [VO(OPr)3] and trianionic tetradentate N,N-bis(2-methylene-4,6-alkylphenolate)aminoethanolate ligands, [L13– (4,6-dimethyl), L23– (4-methyl, 6-tert-butyl), L33– (4-tert-butyl, 6-methyl), L43– (4,6-di-tert-butyl)], afford mononuclear complexes [VO(L1)] (1) and [VO(L2)] (2) with a tri...

The reaction of WOCl(4) with 2,4-di-tert-butyl-6-((isopropylamino)methyl)phenol followed by the reaction with phenyl isocyanate leads to the formation of imidotungsten(VI) complex [W(NPh)Cl(3)(OC(6)H(3)(CH(2)NH-i-Pr)-2-t-Bu(2)-4,6)] 4 with a chelating aminophenolate ligand. When the same procedure was applied using aminophenols with bulkier substit...

Dioxomolybdenum(VI) and oxotungsten(VI) complexes with a new amine bisphenol ligand (H2L) are reported. The ligand which carries a neutral nitrogen atom, two phenolic oxygen atoms and a thiophene side-arm was synthesized by a simple one-pot Mannich reaction. Further reaction with [MoO2(acac)2] yielded a monomeric molybdenum complex [MoO2(L)(MeOH)]...

Dioxomolybdenum(VI) complex [MoO2Cl2(dmso)2] reacts with a series of tetradentate O3N-type aminoalcohol–bisphenol ligands to form oxomolybdenum(VI) complexes of type [MoOCl(Ln)]. The reaction of H3L1 produces [MoOCl(L1)] as two separable isomers, whereas the reaction of H3L2 or H3L3 yields a single product. The X-ray analyses of cis- and trans-[MoO...

A new dioxomolybdenum(VI) complex with a chiral tetradentate ligand (N,N-bis(2-hydroxy-3,5-dimethylbenzyl)-N',N'-dimethyl-3-phenylpropane-1,2-diamine) is reported. The tripodal ligand contg. two nitrogen atoms and two phenolic oxygen atoms was synthesized starting from a chiral diamine precursor. Further reaction with [MoO2(acac)2] yielded a monome...

The reactions of trans-[MoO(ONOMe)Cl2] 1 (ONOMe=methylamino-N,N-bis(2-methylene-4,6-dimethylphenolate) dianion) and trans-[MoO(ONOtBu)Cl2] 2 (ONOtBu=methylamino-N,N-bis(2-methylene-4-methyl-6-tert-butylphenolate) dianion) with PhNCO afforded new imido molybdenum complexes trans-[Mo(NPh)(ONOMe)Cl2] 3 and trans-[Mo(NPh)(ONOtBu)Cl2] 4, respectively. A...

The reaction between tungsten(VI) complex [W(eg)3] (eg=1,2-ethanediolato dianion) and a phenolic ligand precursor 2,4-di-tert-butyl-6-(((2-hydroxyethyl)(methyl)amino)methyl)phenol (H2L) affords a monomeric oxotungsten complex [WO(eg)(L)]. This complex reacts further with Me3SiCl, which leads to the displacement of ethanediolato ligand from the comp...

W(VI) and Mo(VI) complexes [MO(L1)Cl2] and [M(X)(L2)Cl3] (X = O, NPh) with tridentate aminobis(phenolate) ligand L1 = methylamino-N,N-bis(2-methyl-4,6-dimethylphenolate) and bidentate aminophenolate ligand L2 = 2,4-di-tert-butyl-6-((dimethylamino)methyl)phenolate were prepd. and characterized. These complexes are principally stable in open atm. und...

The syntheses and crystal structures of four new uranyl complexes with [O,N,O,N′]-type ligands are described. The reaction between uranyl nitrate hexahydrate and the phenolic ligand [(N,N-bis(2-hydroxy-3,5-dimethylbenzyl)-N′,N′-dimethylethylenediamine)], H2L1 in a 1:2 molar ratio (M to L), yields a uranyl complex with the formula [UO2(HL1)(NO3)]·CH...

Dioxomolybdenum(VI) complex [MoO2(Heg)2] (H2eg=1,2-ethanediol) reacts with phenolic ligand precursors tris(2-hydroxy-3,5-dimethylbenzyl)amine (H3LMe) and tris(2-hydroxy-3,5-di-tert-butylbenzyl)amine (H3LtBu) to form oxomolybdenum(VI) complexes of type [MoO(LR) (Heg)]. The Heg ligand can be replaced by other alcohols (i.e. 2-aminoethanol, 2-amino-2-...

Oxotungsten(VI) complex cis-[WO(LtBu)Me2] (LtBu = methylamino-N,N-bis(2-methylene-4-methyl-6-tert-butylphenolate) dianion) was prepd. by the transmetallation reaction of [WO(LtBu)Cl2] (either cis or trans isomer) with Me magnesium iodide. This unexpectedly stable dialkyl complex can be activated by Et2AlCl to catalyze the ring-opening metathesis po...

The dioxidotungsten(VI) and -molybdenum(VI) complexes [WO2(O2NOMe)] (1), [MoO2(O2NOMe)] (2) and [{MoO2(O2NMe)}2] (3) [O2NOMe methoxyethylamino-N,N-bis(2-methylene-4,6-dimethylphenolate) dianion, O2NMe = methylamino-N,N-bis(2-methylene-4,6-dimethylphenolate) dianion] can react with chloride sources (Me3SiCl, SOCl2) to form resultant monooxido dichlo...

Aminobis(phenol) ligands H2L = QN(CH2(2-OH-3,5-R2C6H2))2 (Q = Me2NCH2CH2-, 2-pyCH2-, MeOCH2CH2-; R = Me, tBu) were used in the prepn. of new tungsten and molybdenum complexes. Treatment of [W(eg)3] (eg = 1,2-ethanediolate dianion) with H2L under hydrolytic conditions in a CHCl3/MeOH mixt. gave the cis-dioxotungsten(VI) complexes [WO2(L)] in good yi...

Trisdiolatotungsten(VI) complex [W(eg)(3)] (eg = 1,2-ethanediolato dianion) reacts in refluxing toluene solution with phenolic ligand precursors tris(2-hydroxy-3,5-dimethylbenzyl)amine (H3LMe) and tris(2-hydroxy-3,5-di-tert-butylbenzyl)amine (H3LtBu) to form monomeric oxotungsten(VI) complexes [WO(L-Me)(Heg)] and [WO(L-tBu)(Heg)], respectively. The...

The reaction of tris(1,2-ethanediolate)tungsten(VI) with tetradentate diaminobis(phenol)s (H 2ONNO R) in the presence of water yields dioxotungsten(VI) complexes of type WO 2(ONNO R). These complexes can catalyse ROMP of norbornene when activated by Et 2AlCl. They can also catalyse oxotransfer reaction between DMSO and benzoin. Two new tungsten(VI)...

The reactions of tridentate ligands, bis(2-hydroxy-3,5-dimethylbenzyl)methylamine (H2ONOMe) and bis(2-hydroxy-3-tert-butyl-5-methylbenzyl)methylamine (H2ONOtBu) with [MoO2(acac)2] (1) in methanol lead to the precipitation of monomeric dioxomolybdenum(VI) complexes [MoO2(ONOMe)(MeOH)]·MeOH (2a) and [MoO2(ONOtBu)(MeOH)]·MeOH (2b), respectively. Ident...

The reaction between trisdiolatotungsten(VI) complex [W(eg)(3)] (1) (eg = 1,2-ethanediolato dianion) and phenolic ligand precursor methylamino-N,N-bis(2-methylene-4,6-dimethylphenol) (H(2)L(Me)) or methylamino-N,N-bis(2-methylene-4-methyl-6-tert-butylphenol) (H(2)L(tBu)) affords monomeric oxotungsten complex [WO(eg)(L(Me))] (2) or [WO(eg)(L(tBu))]...

The synthesis, characterization and applications of heteroatom-substituted group 4 bis(indenyl)metallocene complexes is reviewed. In recent years, an increasing number of group 4 metallocenes with electronically modified cyclopentadienyl ligands have been reported with, in some cases, considerably altered catalytic properties. This microreview focu...

Addition of two equivalents of tris(2-hydroxy-3,5-dimethylbenzyl)amine (H3Lig) to the solution of MoO2(acac)2 in MeOH results in the formation of anionic complex, which precipitates as LigH4[MoO2Lig], a yellow crystalline solid. Crystal structure determinations reveal that the asymmetric unit consists of one [MoO2Lig]− anion, one H4Lig+ cation and...

Reaction of monomeric tungsten(VI) complex [W(eg)3] (1) (eg=1,2-ethanediolate dianion) with either one or 2 equiv. of 2,2′-methylenebis(6-alkylphenol) [alkyl=Me (H2L1), iPr (H2L2), tBu (H2L3)] provides heteroleptic complexes [W(eg)2(Ln)] (2) and [W(eg)(Ln)2] (3), respectively. Sterically hindered ligand precursor H2L3, which bear bulky tert-butyl g...

A 1:1 complex between copper(II) chloride and cis-1,3-cyclohexanediol has been synthesized and its crystal structure determined. The structure is composed of two different dinuclear [CuCl2(c-13chd)]2 units in which the copper(II) ions are surrounded by the two oxygen atoms of the diol and the two halide ions in a distorted cis-square planar arrange...

The reaction of bulky ligand precursor 2,2′-methylenebis(4-methyl-6-tert-butylphenol) (H2mbp) or 2,2′-ethylidenebis(4,6-di-tert-butylphenol) (H2ebp) with trisdiolatotungsten(VI) complex [W(eg)3] 1 (eg=ethanediolate dianion) provides heteroleptic complexes [W(mbp)(eg)2] 2 or [W(ebp)(eg)2] 3, respectively. Sterically less hindered 2,2′-dihydroxy-1,1′...

Tungsten(VI) complexes of the type trans-[WCl2(diol)(OAr)2] were studied as catalyst precursors for ROMP of norbornene and dicyclopentadiene. These compounds form active catalysts when treated by simple Grignard reagents, such as methyl magnesium iodide or neophyl magnesium chloride. Moreover, polymerisations can be run under ambient atmosphere wit...

Two oxotungsten(VI) complexes of the type [WOCl2(OAr)2] (OAr=OC6H3tBu-2-Me-6 or OC6H2tBu-2-Br-4-Me-6) were prepared by the reaction of WOCl4 with 2 equiv. of phenolic ligand precursors in a refluxing toluene solution. Both compounds form monomeric units, in which the tungsten ion has adopted a square pyramidal coordination geometry with the oxo l...

Coordinated phenoxide groups in [W(eg)(2)(mephe)(2)] (2a) and [W(eg)(2)(prphe)(2)] (2c) (eg = ethanediolate dianion; mephe = OC(6)H(3)Me(2)-2,6; prphe = OC(6)H(3)(i)Pr(2)-2,6) undergo reaction with Br(2), leading to substitution at the para position of the phenyl rings and formation of the complexes [W(eg)(2)(OC(6)H(2)R(2)-2,6-Br-4)(2)] (2b, R = Me...

Bisdiolatotungsten(VI) complexes of the type [W(diol)(2)(phe)(2)] and [W(diol)(2)(biphe)] (diol = aliphatic diolate dianion, phe = substituted phenolate, biphe = substituted biphenolate) were studied as catalyst precursors for ring opening metathesis polymerization of norbornene and dicyclopentadiene. These compounds form active catalysts when acti...

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and...

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and...

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Racemic 6,6′-disubstituted-1,1′-bi-2-naphthols H2X2bino (X=H, Br) and corresponding binaphthyl acetates react with trisdiolatetungsten(VI) complexes [W(eg)3] and [W(eg)(pin)2] (eg=ethanediolate dianion, pin=pinacolate dianion) forming heteroleptic complexes [W(X2bino)(diolato)2]. The X-ray crystal structure determinations confirmed that the isolate...

Treatment of the zwitterionic amine tricarbollides of general formula 7-L-nido-7,8,9-C3B8H10 (1) (where L = Me2HN (1c) and ButH2N (1d)) with [(eta 5-C5H5)Fe(CO)2]2 in refluxing mesitylene resulted in the formation of a mixture of the known compounds [2-(eta 5-C5H5)-9-X-closo-2,1,7,9-FeC3B8H10] (2) (where X = H2N (2a), Me2N (2c), and ButHN (2d)) and...

Treatment of the zwitterionic amine tricarbollides of general formula 7-L-nido-7,8,9-C3B8H10 (1) (where L = Me2HN (Ic) and Bu'H2N (Id)) with [(eta(5)-C5H5)Fe(CO)(2)](2) in refluxing mesitylene resulted in the formation of a mixture of the known compounds [2-(eta(5)-C5H5)-9-X-closo-2, 1,7,9-FeC3B8H10] (2) (where X = H2N (2a), Me2N (2c), and Bu'HN (2...

The continued and evolving significance of boron chemistry to the wider chemical community is demonstrated by the international and interdisciplinary nature of the research reported in this book. Contemporary Boron Chemistry encompasses inorganic and organic compounds as well as polymers, solid-state materials, medicinal aspects and theoretical stu...

The synthesis and characterisation of four monomeric cis-dioxomolybdenum(VI) complexes involving Schiff base ligands is described. Ligands were obtained by condensation of salicylaldehyde with substituted aminoethanols. [MoO2(acac)2] reacted with the prepared ligands forming six-coordinated cis-dioxoMo(VI) complexes. X-ray diffraction studies confi...

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and...

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and...

Mo trioxides MoO3 or MoO3·2H2O reacted with alc. ethers (HOROR') to form [MoO2(OROR')2] where HOROR' = 2-methoxyethanol (Hmet) or tetrahydropyran-2-methanol (Hpyr). In these compds. the MoVI has a distorted octahedral coordination geometry. The reaction of [MoO2(pyr)2] with the ditertiary diol 1,1'-bicyclohexane-1,1'-diol (H2bicy) in MeCN soln. pro...

Reactions between 7-L-nido-7,8,9-C3B8H10 compds. (L = ButNH2, Me2NH) and [NMe3H]+[7,8-C2B9H12]- in the presence of NaH, followed by the addn. of anhyd. CoCl2 and prolonged heating in diglyme at reflux, resulted in the isolation of mixed-ligand 12-vertex cobaltacarboranes [closo-(9-R2N-1,7,9-C3B8H10)-commo-2,(3')-Co-(1',2'-C2B9H11)] (I, R = H, Me)....

Reaction of OsO4 with one equiv. of PPh3 in the presence of the tertiary diols, 2,3-dimethyl-2,3-butanediol (H2pin) and 1,1'-bicyclohexane-1,1'-diol (H2bicy), afforded the new oxoosmium(VI) complexes [OsO(diol)2]. The mol. structures of [OsO(pin)2], [OsO(bicy)2] and its adduct [OsO(bicy)2]·H2bicy·PPh3O were detd. by x-ray crystallog. [on SciFinder(...

Tungsten (VI) complex [W(eg)3] (eg=ethanediolate dianion) reacts with phenyl acetates leading to the displacement of one or three diolato ligands. Two types of phenoxides, [W(O–C6H4R-4)6] (R=H, Me, Cl) and [W(eg)2 (OC6H3R2′-2,6)2] (R′=Me, i Pr) are formed, depending on the nature of phenyl group. The X-ray crystal structure determinations of [W(OC6...

The compound Re2O7, Re2O7·2H2O or [ReO3(OSiMe3)] reacted with H2diol to form complexes having the general formula [ReO3(Hdiol)] where H2diol = 2,3-dimethylbutane-2,3-diol (H2pin) or 1,1′-bicyclohexane-1,1′-diol (H2bicy). In the case of H2pin the complex [ReO3(Hpin)]·H2pin is formed initially in the reaction of rhenium(VII) oxides with an excess of...

Air- and moisture stable tungsten(VI) calixarene complex was prepared from [W(eg)3] (H2eg = 1,2–ethanediol) and H4tbcalix (p–tert–butylcalix[4]arene) by a ligand exchange reaction. X-ray structure of [W(tbcalix)(eg)] reveals that tungsten ion is octahedrally surrounded by six oxygen atoms. The reaction of the obtained complex with thionyl chloride...

The title compound, [WOCl(C6H12O2)(C6H13O2)], is a neutral complex in which the central tungsten(VI) cation is bonded to one chloro, one ore, one diolato and one hydrogendiolato ligand resulting in a distorted octahedron around the W-VI atom. Adjacent complex molecules are linked into dimers by O-H...Cl hydrogen bonds.

The synthesis and characterization of three siloxy-substituted zirconocene complexes rac- and meso-ethylenebis[1-(tert-butyldimethylsiloxy)indenyl]zirconium dichlorides (3a,3b) and rac-ethylenebis[1-(tert-butyldimethylsiloxy)-4,5,6,7-tetrahydroindenyl]zirconium dichloride (4) are reported. The molecular structures of 3b and 4 have been determined a...

The synthesis and characterization of an unbridged metallocene catalyst precursor bis[2-(tert-butyldimethylsiloxy)-4,7-dimethylindenyl]zirconium dichloride (3) is reported. The solid state structure of 3 reveals two different rotamers in the asymmetric unit corresponding to a C1 symmetric, `central/lateral:gauche'-like conformation, and a C2 symmet...

The synthesis and molecular structure of rac-[ethylenebis(2-(thexyldimethylsiloxy)indenyl)]zirconium dichloride (4), is reported. In combination with methylaluminoxane (MAO), 4 forms an active catalyst system for homogeneous polymerization of ethylene and propylene. The high activity of 4/MAO is retained at low [Al]:[Zr] ratios [(150–250):1]. Decre...

The synthesis and characterization of 1- and 2-triisopropylsiloxy substituted bis(indenyl) zirconocenes is reported. The mol. structures of rac-[ethylenebis(2-(triisopropylsiloxy)-1-indenyl)]zirconium dichloride (6) and rac-[ethylenebis(2-(triisopropylsiloxy)-4,5,6,7-tetrahydro-1-indenyl)]zirconium dichloride (8) were detd. and reveal that complex...

Re2O7, Re2O7·2H2O or [ReO3(OSiMe3)] reacted with H2diol to form [ReO3(Hdiol)] where H2diol = 2,3-dimethylbutane-2,3-diol (H2pin) or 1,1'-bicyclohexane-1,1'-diol (H2bicy). In the case of H2pin [ReO3(Hpin)]·H2pin is formed initially in the reaction of rhenium(VII) oxides with an excess of pinacol. The hydrogen bonded free pinacol mol. can be removed...

Treatment of 4,7-dimethyl-2-indanone with tert-butyldimethylchlorosilane gave 2-(tert-butyldimethylsiloxy)-4,7-dimethylindene which was deprotonated and treated with ZrCl2 to give bis[2-(tert-butyldimethylsiloxy)-4,7-dimethylindenyl]zirconium dichloride (I). X-ray structure anal. of I revealed two rotamers in the asym. unit corresponding to a C1 sy...

The synthesis and characterization of two new Si-C bridged ansa-bis(fluorenyl) and ansa-bis(octahydrofluorenyl) zirconocene complexes, (Flu-CH2-SiMe2-Flu)ZrCl2 (3) and (FluH8-CH2-SiMe2-FluH8)ZrCl2 (4) is reported. Compd. 3, in combination with methylaluminoxane (MAO), forms an active catalyst system for homogeneous polymn. of ethylene. The mol. str...

Ethylene and propylene were polymerized over the siloxy-substituted bis(indenyl) ansa-metallocenes, rac-[ethylenebis(2-(tert-butyldimethylsiloxy)indenyl)]zirconium dichloride (1), rac-[ethylenebis(2-(tert-butyldimethylsiloxy)-4,5,6,7-tetrahydroindenyl)]zirconium dichloride (2), and rac-[ethylenebis(2-(tert-butyldimethylsiloxy)indenyl)]hafnium dichl...

Three tungsten complexes were investigated as precursors to silica-supported tungsten oxide catalysts. The catalytic properties of the active catalysts in propene metathesis is reported. 15 refs., 1 fig., 2 tab.

Diss. -- Turun yliopisto.

A W(VI) complex [WCl2(pin)2] (1) [H2pin = pinacol (2,3-dimethylbutane-2,3-diol)] reacted with H2O forming dimeric [W2O3(pin)2(Hpin)2], but in the presence of tripropylamine [(NPr3H)2Cl]2[W6O19] (2) was formed. The reaction of 1 with H2pin led to [W(pin)3] and with phenol (PhOH) to [W(pin)2(OPh)2] (3). The structures of 2 and 3 were confirmed by x-r...

The title compd., [W(C3H5ClO2)(C6H12O2)2], is a mononuclear complex in which the central W(VI) cation is surrounded by six O donors of three chelating diolato ligands. The WO6 unit adopts a distorted octahedral geometry. Crystallog. data and at. coordinates are given.

The tungsten(VI)diolato complex, [W(eg)(pin)2] (H2eg = 1,2-ethanediol, H2pin = 2,3-dimethyl-2,3-butanediol) forms adducts with phenol and aniline. X-ray structural studies and spectral measurements (UV and IR) show that the formation of those adducts is due to hydrogen bonding between OH or NH2 groups of adductant and diolato oxygen atoms. The effe...

The substitution of a diolato ligand by two chlorides around a tungsten(VI) centre was carried out by thionyl chloride in dichloromethane. The preparation and structure of cis-[WCl2(pin)2] (pin = 2,3-dimethyl-2,3-butanediolato) is described.

Neutral W(VI) complexes [W(eg)(pin)2] (2) and [W(pin)3] (3) (eg = 1,2-ethanediolato ligand, pin = 2,3-dimethyl-2,3-butanediolato ligand) were prepd. from [W(eg)3] (1) and H2pin by a diol exchange reaction. The x-ray crystal structures of the compds. were detd. In both complexes, the central W atom of the monomer is octahedrally coordinated by six O...

Dinuclear complexes [W2O3L2(HL)2][H2L = 2,3-dimiethylbutane-2,3-diol (H2pin), trans-cycloheptane-1,2-diol (H2chpd) or trans-cyclooctane-1,2-diol (H2cocd)] were prepared in high yield by hydrolysis of [W(eg)(pin)2](H2eg = ethane-1,2-diolate), [W(chpd)3] and [W(cocd)3] in alcoholic solution. X-Ray diffraction studies showed that each tungsten(VI) ion...

The catalyst comprises an aftertreated W complex, which contains diol ligands and hydrocarbon ligands, which latter are benzenes substituted with a lower alkyl group. Stirring 0.613 g WCl6, 0.994 g (Bu)4N+ nitrate, 3.10 mmol pinacol in 25 mL PhMe at reflux for 6 h, sepg. the lower orange soln., adding 10.0 mL THF, 3.1 mmol Mg, and 3.1 mmol Br mesit...