Elektrochemische synthesen: XXII. Die kathodische reduktion von pentacarbonyl-chrom-halogenphosphanen

The cathodic reduction of the trihalophosphane complexes (CO)₅CrPX₃ (1a, X = Cl; 1b, X = Br) leads to the binuclear complexes (CO)₅ Cr(X₂PPX₂)Cr(CO)₅, (2a, X = Cl; 2b, X = Br). Reductive dehalogenation of coordinated organodihalophosphanes, (CO)₅CrPRX₂ (3a, R = Me, X = Cl; 3b, R = Ph, X = Cl; 3c, R = Me, X = Br; 3d, R = Ph, X = Br), in the presence of dimethyldisulfane yields bis(methylthio)organophosphane complexes, (CO)₅CrPR(SCH₃)₂ (5a, R = Me; 5b, R = Ph). The phosphinidene complexes (CO)₅ CrPR are discussed as the reactive intermediates.The organodibromophosphane complexes 3c and 3d can also be partially reduced in the presence of dimethyldisulfane, and (CO)₅CrPBrR(SCH₃) (7a, R = Me; 7b, R = Ph) is obtained. Radical intermediates are probable.     

Reactions of tBu2P–PLi–PtBu2 with [(Et3P)2MCl2] (M = Ni,Pd, Pt). Synthesis and Properties of [(1,2‐η‐tBu2P=P–PtBu2)M(PEt3)Cl] (M=Ni,Pd)

^tBu₂P–PLi–P^tBu₂·2THF reacts with [cis‐(Et₃P)₂MCl₂] (M = Ni, Pd) yielding [(1,2‐η‐^tBu₂P=P–P^tBu₂)Ni(PEt₃)Cl] and [(1,2‐η‐^tBu₂P=P–P^tBu2)Pd(PEt₃)Cl], respectively. ^tBu₂P– PLi–P^tBu₂ undergoes an oxidation process and the ^tBu₂P–P–P^tBu₂ ligand adopts in the products the structure of a side‐on bonded 1,1‐di‐tert‐butyl‐2‐(di‐tert‐butylphosphino)diphosphenium cation with a short P–P bond. Surprisingly, the reaction of ^tBu₂P–PLi–P^tBu₂·2THF with [cis‐(Et₃P)₂PtCl₂] does not yield [(1,2‐η‐^tBu₂P=P–P^tBu₂)Pt(PEt₃)Cl].     

Alkynylhalocarbenes. 4. Generation of (alk-1-ynyl)halocarbenes from 3-substituted 1,1,1,3-tetrahalopropanes under the action of bases

When treated with KOH under phase-transfer catalysis or with Bu^tOK, 3-substituted (alkyl or phenyl) 1,1,3-tribromo-1-fluoropropanes 1a—c exclusively generate previously unknown (alk-1-ynyl)fluorocarbenes 5a—c, which react with olefins to give 1-(alk-1-ynyl)-1-fluorocyclopropanes 6a—h in 12—69% yields. Under analogous conditions, 3-alkyl- and 3-aryl-3-bromo-1,1,1-trichloropropanes 2a—c selectively afford (alk-1-ynyl)chlorocarbenes 7a—c, which are trapped by olefins to form the corresponding 1-(alk-1-ynyl)-1-chlorocyclopropanes 8a—k in 35—70% yields. (Phenylethynyl)chlorocarbene 7a is also selectively generated from 1,1,1,3-tetrachloro-3-phenylpropane (3a) upon its treatment with Bu^tOK. With an excess of 2,3-dimethylbut-2-ene or 2-methylpropene, carbene 7a yields 1-chloro-1-(phenylethynyl)cyclopropanes 8a or 8c, respectively. In contrast, 1,1,1,3-tetrachloroheptane 3b and 3-alkyl- and 3-phenyl-1,1,1,3-tetrabromopropanes 4a,c,f react with bases in the presence of olefins to give, along with the corresponding 1-(alk-1-ynyl)-1-halocyclopropanes 8a,c,d and 11a—f, vinylidenecyclopropanes 12a,c—g, which suggests the generation, under these conditions, both (alk-1-ynyl)halocarbenes 7b and 9a—c and vinylidenecarbenes 10 and 11a—c. The composition and structures of intermediate products in the reactions of tetrahalides 1b, 2a, 2b, 3a, and 3b with Bu^tOK were determined and the mechanisms for carbene generation in these reactions were proposed.     

Ethylene/1-hexene copolymerization by salicylaldiminato vanadium(III) complexes activated with diethylaluminum chloride

Mono salicylaldiminato vanadium（Ⅲ） complexes（1a-1f）[RN = CH（ArO）]VCl₂（THF）₂（Ar = C₆H₄（1a-1e）,R = Ph,1a;R = p-CF₃Ph,1b;R = 2,6-Me₂Ph,1c;R = 2,6-iPr₂Ph,1d;R = cyclohexyl,1e;Ar = C₆H₂tBu₂（2,4）,R = 2,6-iPr₂Ph, 1f） and bis（salicylaldiminato） vanadium（Ⅲ） complexes（2a-2f）[RN = CH（ArO）]₂VCl（THF）_x（Ar = C₆H₄（2a-2e）,x = 1 （2a-2e）,R = Ph,2a;R =p-CF₃Ph,2b;R = 2,6-Me₂Ph,2c;R = 2,6-iPr₂Ph,2d;R = cyclohexyl,2e;Ar = C₆H₂tBu₂（2,4）,R = 2,6-iPr₂Ph,x = 0,2f） have been evaluated as the active catalysts for ethylene/1-hexene copolymerization in the presence of Et₂AlCl.The ligand substitution pattern and the catalyst structure model significantly influenced the polymerization behaviors such as the catalytic activity,the molecular weight and molecular weight distribution of the copolymers etc.The highest catalytic activity of 8.82 kg PE/（mmol_V·h） was observed for vanadium catalyst 2d with two 2,6-diisopropylphenyl substituted salicylaldiminato ligands.The copolymer with the highest molecular weight was obtained by using mono salicylaldiminato vanadium catalyst 1f having ligands with tert-butyl at the ortho and para of the aryloxy moiety.     

Die Reaktion von tBu2P‐P=P(Me)tBu2 mit [Fe2(CO)9] und [(η2‐C8H14)2Fe(CO)3]

^tBu₂P‐P=P(Me)^tBu₂ reacts with [Fe₂(CO)₉] to give [μ‐(1, 2, 3:4‐η‐^tBu₂P¹‐P²‐P³‐P^4tBu₂){Fe(CO)₃}{Fe(CO)₄}] ( 1 ) and [trans‐(^tBu₂MeP)₂Fe(CO)₃]( 2 ). With [(η²‐C₈H₁₄)₂Fe(CO)₃] in addition to [μ‐(1, 2, 3:4‐η‐^tBu₂P¹‐P²‐P³‐P^4tBu₂){Fe(CO)₂PMe^tBu₂}‐{Fe(CO)₄}] ( 10 ) and 2 also [(μ‐P^tBu₂){μ‐P‐Fe(CO)₃‐PMe^tBu₂}‐{Fe(CO)₃}₂(Fe‐Fe)]( 9 ) is formed. 1 crystallizes in the monoclinic space group P2₁/c with a = 875.0(2), b = 1073.2(2), c = 3162.6(6) pm and β = 94.64(3)?. 2 crystallizes in the monoclinic space group P2₁/c with a = 1643.4(7), b = 1240.29(6), c = 2667.0(5) pm and β = 97.42(2)?. 9 crystallizes in the monoclinic space group P2₁/n with a = 1407.5(5), b = 1649.7(5), c = 1557.9(16) pm and β = 112.87(2)?.     

Heterodinukleare Komplexe: Synthese und Kristallstrukturen von [RuRh(μ‐CO)(CO)4(μ‐PtBu2)(tBu2PH)], [RuRh(μ‐CO)(CO)3(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] und [CoRh(CO)4(μ‐H)(μ‐PtBu2)(tBu2PH)]

Heterobinuclear Complexes: Synthesis and X‐ray Crystal Structures of [RuRh(μ‐CO)(CO)₄(μ‐P^tBu₂)(^tBu₂PH)], [RuRh(μ‐CO)(CO)₃(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)], and [CoRh(CO)₄(μ‐H)(μ‐P^tBu₂)(^tBu₂PH)] [Ru₃Rh(CO)₇(μ₃‐H)(μ‐P^tBu₂)₂(^tBu₂PH)(μ‐Cl)₂] ( 2 ) yields by cluster degradation under CO pressure as main product the heterobinuclear complex [RuRh(μ‐CO)(CO)₄(μ‐P^tBu₂)(^tBu₂PH)] ( 4 ). The compound crystallizes in the orthorhombic space group Pcab with a = 15.6802(15), b = 28.953(3), c = 11.8419(19) Å and V = 5376.2(11) ų. The reaction of 4 with dppm (Ph₂PCH₂PPh₂) in THF at room temperature affords in good yields [RuRh(μ‐CO)(CO)₃(μ‐P^tBu₂)(μ‐dppm)] ( 7 ). 7 crystallizes in the triclinic space group P 1 with a = 9.7503(19), b = 13.399(3), c = 15.823(3) Å and V = 1854.6 ų. Moreover single crystals of [CoRh(CO)₄(μ‐H)(μ‐P^tBu₂)(^tBu₂PH)] ( 9 ) could be obtained and the single‐crystal X‐ray structure analysis revealed that 9 crystallizes in the monoclinic space group P2₁/a with a = 11.611(2), b = 13.333(2), c = 18.186(3) Å and V = 2693.0(8) ų.     

Komplexchemie P‐reicher Phosphane und Silylphosphane. XXV. Bildung und Struktur des [{cyclo‐P3(PtBu2)3}{Ni(CO)2}{Ni(CO)3}]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XXV. Formation and Structure of [{ cyclo ‐P₃(P^tBu₂)₃}{Ni(CO)₂}{Ni(CO)₃}] ^tBu₂P–P=P(R)^tBu₂ (R = Br, Me) reacts with [Ni(CO)₄] yielding [{cyclo‐P₃(P^tBu₂)₃}{Ni(CO)₂}{Ni(CO)₃}]. The two cis‐^tBu₂P substituents of the cyclotriphosphane, which results from the trimerization of the phosphinophosphinidene ^tBu₂P–P, are coordinating to a Ni(CO)₂ unit forming a five‐membered P₄Ni chelate ring. The trans‐^tBu₂P group is linked to a Ni(CO)₃ unit. The compound crystallizes in the orthorhombic space group Pbca (No. 61) with a = 933.30(5), b = 2353.2(1) and c = 3474.7(3) pm.     

Synthesis and Characterization of Alkyltris(2-pyridyl)phosphonium Salts

Alkytris(2-pyridyl)phosphonium salts [(2-Py) ₃ PR]X 1 [1a, R = Et, X = Br; 1b, R = Pr, X = Br; 1c, R = Bu, X = Br; 1d, R = CH₂Ph, X = Br; 1e, R = CH ₂ Ph, X = Cl] were synthesised from (2-Py) ₃ P and an excess of RCl. 1c and 1e were found to rapidly decompose in hot acetone to 2,2′-bipyridinium(+1) bromide 2 and (2-Py)P(O)(CH ₂ Ph)C(OH)Me ₂ 3, respectively. A reaction mechanism for both products is proposed. All compounds were fully characterized, including X-ray crystallography for 1a and 3 with 1a being the first representative of this class of compounds characterized by this technique.     

1‐Azaallyl Complexes of NiII,PdII, and TiIII

The metal complexes [Ni{N(Ar)C(R)C(H)Ph}₂) ( 2 ) (Ar = 2,6‐Me₂C₆H₃, R = SiMe₃), [Ti(Cp₂){N(R)C(Bu^t)C(H)R}] ( 3 ), M{N(R)C(Bu^t)C(H)R}I [M = Ni ( 4 a ) or Pd ( 4 b )] and [M{N(R)C(Bu^t)C(H)R}I(PPh₃)] [M = Ni ( 5 a ) or Pd ( 5 b )] have been prepared from a suitable metal halide and lithium precursor of ( 2 ) or ( 3 ) or, alternatively from [M(LL)₂] (M = Ni, LL = cod; M = Pd, LL = dba) and the ketimine RN = C(Bu^t)CH(I)R ( 1 ). All compounds, except 4 were fully characterised, including the provision of X‐ray crystallographic data for complex 5 a .     

Allylstannation of α-, β- and γ-diketones mediated by allylbutyltin halides: Bu2(CH2=CHCH2) SnCl and Bu(CH2 =CHCH2) SnCl2

Butane-2,3- (1a), pentane-2,4- (1b) and hexane-2,5-dione (1c) react with Bu₂(CH₂=CHCH₂)SnCl in the presence of water to give monoallylated keto-ols (2a, 2b) and/or diallylated diols (3a, 3b, 3c), this depending upon the employed molar ratio [diketone]/[allyltin chloride]. Bu(CH₂=CHCH₂)SnCl₂ reacts with neat 1c in a one-pot synthesis to give mixtures of heterocyclic compounds: 2,5-diallyl-2,5-dimethyltetrahydrofuran (4), and 3-chloro-1,5-dimethyl-8-oxabicyclo [3,2,1] octane (5). Compound 4 is also obtained in high yield from the corresponding diol 3c by cyclodehydration promoted by RSnCl₃ (R = Me and Bu).     

Molecular ions of 3,3′-bi(2-R-5,5-dimethyl-4-oxopyrrolinylidene) 1,1′-dioxides

The electrochemical reduction of 3,3′-bi(2-R-5,5-dimethyl-4-oxopyrrolinylidene) 1,1′-dioxides (R = CF₃, Me, Ph, Bu^t), which are cyclic dinitrons with conjugated C=C bond, in acetonitrile is an EE process producing stable radical anions and dianions, whereas the electrochemical oxidation is an EEC (R = Me, Ph) or EE process (R = Bu^t) with formation of radical cations (except for the case of R = CF₃) and dications (R = Bu^t) stable under standard conditions. Radical cations of the dioxides with R = Me, Ph, and Bu^t and radical anions of the whole series of the compounds studied, including R = CF₃, were characterized by ESR spectroscopy combined with electrochemical measurements and quantum-chemical calculations. The electrochemical behavior of the Bu^t-substituted dinitron is unique: the EE processes in the region of negative and positive potentials with formation of the dianion, radical anion, radical cation, and dication stable at T = 298 K were observed for the first time within one cycle of potential sweep in the CV curve measured in MeCN. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1148–1154, May, 2005.     

Studies on the reactivity of the clusters [Ru3(CO)8(μ-H)2(μ-PR2)2] (R=But,Cy) towards phosphine ligands

The reaction behavior of the 48e-clusters [Ru₃(CO)₈(μ-H)₂(μ-PR₂)₂] (R=Bu^t, 1a; R=Cy, 1b) towards phosphine ligands has been studied. Whereas 1a reacts spontaneously with many phosphines at room temperature, a lack of reactivity for 1b under similar conditions is observed. Thus 1a reacts with dppm (Ph₂PCH₂PPh₂) to the known 46e-cluster [Ru₃(μ-CO)(CO)₄(μ₃-H)(μ-H)(μ-PBu^t₂)₂(μ-dppm)] (2a), and the reaction of 1a with dppe (Ph₂PC₂H₄PPh₂) yields analogously [Ru₃(μ-CO)(CO)₄(μ₃-H)(μ-H)(μ-PBu^t₂)₂(μ-dppe)] (3). Reactions of 1a with dmpm (Me₂PCH₂PMe₂), dmpe (Me₂PC₂H₄PMe₂) and PBuⁿ₃, respectively, gave in each case a mixture of products which could not be characterized. Contrary to the reaction behavior at room temperature, 1b reacts with phosphines in THF under reflux yielding the novel complexes [Ru₃(CO)₆(μ-H)₂(μ-PCy₂)₂L₂] (L=Cy₂PH, 4a; L=Bu^t₂PH, 4b; L=Ph₂PH, 4c; L=P(OEt)₃, 4d). 4a is also obtained directly by the reaction of [Ru₃(CO)₁₂] with an excess of Cy₂PH. The molecular structure of 4a has been determined by a single-crystal X-ray analysis. Moreover, the thermolysis of 1a in octane affords [Ru₃(CO)₈(μ-H)₂(μ₃-PBu^t)(Bu^t₂PH)] (6) as the main product, and the thermolysis of [Ru₃(CO)₉(Bu^t₂PH)(μ-dppm)] (7) yields 2a to a considerable extent. Treatment of 1a with carbon tetrachloride leads to [Ru₃(CO)₇(μ-H)(μ-PBu^t₂)₂(μ-Cl)] (8) as the main product.     

Reactivity of titanium imidazolin-2-iminato complexes with 2,6-diisopropylaniline and 2-{(2,6-diisopropylphenyl)-iminomethyl}pyrrole

Abstract

We report the reactions of imidazolin-2-iminato titanium complexes [(Im^RN)Ti(NMe₂)₃] (R = Mes, 2b; R = Dipp, 2c; Mes = mesityl, Dipp = 2,6-diisopropylphenyl) with 2,6-diisopropylaniline in a 1:3 molar ratio to yield the titanium imido complexes of composition [(Im^RNH)Ti = N(^Dipp)(HN^Dipp)₂] (R = Mes, 3b; R = Dipp, 3c) in good yield by the Ti-Niminato bond cleavage at 60 °C. In contrast, the reaction of [(Im^RN)Ti(NMe₂)₃] with 2,6-diisopropylaniline in a 1:1 molar ratio afforded mono-substituted products [(Im^RN)Ti(NMe₂)₂(HN^Dipp)] (R = Mes, 4b; R = Dipp, 4c) in good yield. The reaction of [(Im^RN)Ti(NMe₂)₃] with the iminopyrrole ligand [2-(2,6-iPr₂C₆H₃-N = CH)C₄H₃NH] (N^DippPyH) in a 1:1 ratio afforded mixed ligands, titanium complexes [(Im^RN)Ti(NMe₂)₂(N^Dipp-Py)] (R = tBu, 5a; R = Dipp, 5c) with imidazolin-2-iminato and iminopyrrolide ligands. Molecular structures of 3b, 3c, 4c, 5a, and 5c were determined by single-crystal X-ray analysis. The solid-state structures of 3b and 3c clearly indicate the formation of true Ti = N double bonds, measuring 1.730(2) Å and 1.727(1) Å, respectively. The solid-state structures of 5a and 5c reveal the formation of five-coordinate titanium complexes.     

Synthesis and reactivity of asymmetrically substituted ansa-bridged zirconocene complexes: X-ray crystal structures of [Zr{R(H)C(η-C5Me4)(η-C5H4)}Cl2] (R = Bu, Bu) and [Zr{Bu(H)C(η-C5Me4)(η-C5H4)}(CH2Ph)2]

The dialkyl complexes, (R = Prⁱ, R′ = Me (2a), CH₂Ph (3a); R = Buⁿ, R′ = Me (2b), CH₂Ph (3b); R = Bu^t, R′ = Me (2c), CH₂Ph (3c); R = Ph, R′ = Me (2d), CH₂Ph (3d)), have been synthesized by the reaction of the ansa-metallocene dichloride complex, [Zr{R(H)C(η⁵-C₅Me₄)(η⁵-C₅H₄)}Cl₂] (R = Prⁱ (1a), Buⁿ (1b), Bu^t (1c), Ph (1d)), and two molar equivalents of the alkyl Gringard reagent. The insertion reaction of the isocyanide reagent, CNC₆H₃Me₂-2,6, into the zirconium-carbon σ-bond of 2 gave the corresponding η²-iminoacyl derivatives, [Zr{R(H)C(η⁵-C₅Me₄)(η⁵-C₅H₄)}{η²-MeCNC₆H₃Me₂-2,6}Me] (R = Prⁱ (4a), Buⁿ (4b), Bu^t (4c), Ph (4d)). The molecular structures of 1b, 1c and 3b have been determined by single-crystal X-ray diffraction studies.     

Cycloaddition of C60 fullerene to stable 2-RSO2-benzonitrile oxides

The interaction of stable 2-RSO₂-benzonitrile oxides1a−c (R=Ph, Bu^t, or PhMeN) with C₆₀ fullerene proceeds at the double (6,6)-bond of fullerene as the [3+2] cycloaddition to form the corresponding isoxazolines2a−c. The molecular structure of compound2b was established by X-ray structural analysis. The interaction of C₆₀ fullerene with 2-(5-methyl-4-nitrothiophene)carbonitrile sulfide, which was obtained by thermolysis of 5-(5′-methyl-4′-nitro-2′-thienyl)1,3,4-oxathiazol-2-one, affords only unstable products. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 118–126, January, 1997.     

Photolysis of some unsymmetrical phosphinic azides in methanol: Relative migratory aptitudes of alkyl groups and phenyl in the curtius-like rearrangement

When an alkylphenylphosphinic acid PRhP(O)N₃ (R = Me, Et, Prⁱ, or Bu^t) is photolysed in MeOH either the alkyl or phenyl group can migrate from P to N in the Curtius-like rearrangement. The composition of the product shows that migration of the alkyl group R is preferred. However, the preference is not great and decreases as R changes Bu^t→Prⁱ→Et→Me (approx. migratory aptitudes relative to Ph: 2.1, 1.7, 1.3 and 1.2 respectively), probably because the PhP bond is better able to assume the correct conformation for Ph migration when R is less bulky. For t-butylmethylphosphic azide there is very little preference for migration of Bu^t relative to Me. Small amounts of unrearranged products such as Bu^tPhP(O)NHOMe and Bu^tPhP(O)NH₂ are generally produced in the photolyses, together with the methyl phosphinates RPhP(O)OMe (major product when R = Me) resulting from (non-photochemical) solvolysis of the azide.     

Sekundäre Phosphinchalkogenide. VII. Synthese von Bis(tert.-butylphosphino)ethan,ButHPCH2CH2PHBut,und 1-tert.-Butylphosphino-2-diphenylphosphino-ethan,Ph2PCH2CH2PHBut,sowie deren sekundäre Phosphinchalkogenide

Secondary Phosphine Chalcogenides. VII. Synthesis of Bis(tert.-butylphosphino)thane, Bu^tHPCH₂CH₂PHBu^t, and 1-tert.-Butylphosphino-2-diphenylphosphinoethane, Ph₂PCH₂CH₂PHBu^t, as well as their Secondary Phosphine Chalcogenides The reaction of Cl₂PCH₂CH₂PCl₂ with Bu^tMgCl gives Bu^tClPCH₂CH₂PClBu^t which is either hydrolysed to yield Bu^tH(O)PCH₂CH₂P(O)HBu^t or reduced to give Bu^tHPCH₂CH₂PHBu^t. This phosphine reacts with sulfur or selenium to give Bu^tH(E)PCH₂CH₂P(E)HBu^t (E = S, Se). Treatment of Ph₂PCH₂CH₂Cl with LiPHBu^t results Ph₂PCH₂CH₂PHBu^t which is oxidized to give Ph₂(E)PCH₂CH₂P(E)HBu^t (E = O, S, Se). The Ph₂P group appears to be oxidized primarily. The compounds obtained are characterized by means of I.R. ¹H and ³¹P-N.M.R. spectroscopy.     

The alkoxides of zirconium and hafnium: direct electrochemical synthesis and mass-spectral study. Do “M(OR)4”, where M=Zr,Hf, Sn,really exist?

The direct electrochemical synthesis of zirconium (1a) and hafnium (1b) alkoxides, M(OPrⁱ)₄·PrⁱOH, Zr(OBuⁱ)₄·BuⁱOH (4a) and M(OR)₄, where R=Et (2a,b), Buⁿ (3a), Bu^s (5a), C₂H₄OMe (6a,b) has been carried out by anodic oxidation of metals in anhydrous alcohols in the presence of LiCl as a conductive additive to give quantitative yields. The solubility polytherms and dissociation pressure of1a,b have been investigated. It has been proved by means of chemical analysis, X-ray powder, and IR spectral studies that the desolvation of 1a,b and Sn(OPrⁱ)₄·PrⁱOH (1c) is accompanied by the formation of amorphous oxocompounds M₃O(OPr_i)₁₀. On the basis of¹H NMR data it has been proved that the structure of the latter is analogous to that of known triangular cluster molecules M₃(₃-O)(₃-OR)(-OR)₃(OR)₆, where M=Mo, W, U. Mass-spectral data and the determined physicochemical characteristics of1–5 permit to conclude that the samples of composition M(OR)₄, where M=Zr, Hf, and2,3,5 contain tri- and tetranuclear oxocomplexes M₃O(OR)₁₀ and M₄O(OR)₁₄ respectively, along with Zr(OR)₄ oligomers of different molecular complexity.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 752–760, April, 1995.     

Binary and ternary oxorhenium(V) complexes: synthesis,characterization, and crystal structure

A series of anionic five-coordinate binary oxorhenium(V) complexes with dithiolato ligands, Bu₄N[ReO(L¹)₂] (1a), Bu₄N[ReO(L²)₂] (1b), and Bu₄N[ReO(L³)₂] (1c), and a series of neutral octahedral ternary oxorhenium(V) complexes of mixed dithiolato and bipyridine ligands, [ReO(L¹)(bpy)Cl] (2a), [ReO(L²)(bpy)Cl] (2b), and [ReO(L³)(bpy)Cl] (2c) (where L¹H₂ = ethane-1,2-dithiol, L²H₂ = propane-1,3-dithiol, L³H₂ = toluene-3,4-dithiol, and bpy = 2,2′-bipyridine), were isolated and characterized by physicochemical and spectroscopic methods. The solid state structure of 1c was established by X-ray crystallography. All the mononuclear oxorhenium(V) complexes are diamagnetic. The redox behavior of all the complexes has been studied voltammetrically.     

Synthesis, characterisation and redox behaviour of isocyanide incorporated, chalcogen stabilised mixed-metal clusters

Room temperature reaction of a benzene solution of [Cp₂Mo₂Fe₂(CO)₇(μ₃-E)(μ₃-E^′)] (EE^′=Se₂ (1), STe (2), SeTe (3)) with PrⁱNC or Bu^tNC resulted in the formation of iron bonded isocyanide clusters [Cp₂Mo₂Fe₂(RNC)(CO)₆ (μ₃-E)(μ₃-E^′)], [E=E^′=Se, R=Prⁱ (5) or Bu^t (9); E=S, E^′=Te, R=Prⁱ (6a, 6b) or R=Bu^t (10a, 10b); E=Se, E^′=Te, R=Prⁱ (7a, 7b) or R=Bu^t (11a, 11b)] and molybdenum bonded isocyanide clusters [Cp₂(RNC)Mo₂Fe₂(CO)₆(μ₃-E)(μ₃-E^′)], [E=E^′=Se, R=Prⁱ(13) or Bu^t (17); E=S, E^′=Te, R=Prⁱ (14) or R=Bu^t, (18); E=Se, E^′=Te, R=Prⁱ (15) or R=Bu^t (19)]. Two isomers (a and b) were detected by ¹H NMR spectroscopy for the mixed-chalcogen clusters 6, 7, 10 and 11, where the isocyanide group is bonded to an iron atom. Thermolytic reaction conditions were necessary for the reaction of [(η⁵-C₅H₅)₂Mo₂Fe₂(CO)₇(μ₃-Te)₂] (4) with Prⁱ NC or Bu^t NC to give [Cp₂Mo₂Fe₂(RNC)(CO)₆(μ₃-Te)₂] (R=Prⁱ (8) or R=Bu^t, (12)) and [Cp₂(RNC)Mo₂Fe₂(CO)₆(μ₃-Te)₂] (R=Prⁱ (8)). Compounds 5-19 have been characterised by IR and ¹H and ¹³C NMR spectroscopy. The Se- and Te-bridged compounds have been further characterised by ⁷⁷Se and ¹²⁵Te NMR spectroscopy. The structures of compounds 12 and 14 were determined by single crystal X-ray diffraction methods. Redox properties of the mixed-metal clusters, 2, 6, 8, 12 and 14 have been studied by cyclic voltammetry in the potential range ±2.5 V at 298 K, using a platinum working electrode.