Reactivity of fac-[PPN][Fe(CO)3(TePh)3]: Structure of Fe2(μTePh)2(NO)4

Addition of NOBF₄ to fac-[PPN][Fe(CO)₃(TePh)₃] in THF at ambient temperature results in formation of Fe₂(μ-TePh)₂(NO)_4l Fe₂(?TePh)₂(CO)₆ and organic products. Methylation of fac-[PPN][Fe(CO)₃- (TePh)₃] by Mel or [Me₃O][BF₄] leads to the known dimer Fe₂(μ.-TePh)₂(CO)₆ and organic products. Fe₂(μ-TePh)₂(NO)₄ crystallizes in the orthorhombic space group P bca, with a = 12.701(5) Å, b = 6.7935(16) Å, c = 21.299(9) Å, V = 1837.8(11) ų, and Z = 4. The core geometry of Fe₂(μ-TePh)₂(NO)₄ is best described as a Fe₂Te₂ planar rhombus with Te-Fe-Te bond angle 112.09(4)°. A Fe-Fe bond (length 2.827(2) Å) is proposed for Fe₂(μ-TePh)₂(NO)₄ on the basis of the 18-electron rule. The iron atom adopts a distorted tetrahedral geometry with acute bridge Fe-Te-Fe angles 67.91(3)°, and bridging Fe-Te bond of length 2.53(1) Å.     

Chelating and Tellurolate Ligand‐Transfer Studies of the Complex fac‐[Fe(CO)3(TePh)3]−: Crystal Structures of Heterodinuclear (CO)3Mn(μ‐TePh)3Fe(CO)3 and CpNi(TePh)(PPh3)

Complex fac‐[Fe(CO)₃(TePh)₃]^? was employed as a “metallo chelating” ligand to synthesize the neutral (CO)₃Mn(μ‐TePh)₃Fe(CO)₃ obtained in a one‐step synthesis by treating fac‐[Fe(CO)₃(TePh)₃]^? with fac‐[Mn‐(CO)₃(CH₃CN)₃]⁺. It seems reasonable to conclude that the d⁶ Fe(II) [(CO)₃Fe(TePh)₃]^? fragment is isolobal with the d⁶ Mn(I) [(CO)₃Mn(TePh)₃]^2? fragment in complex (CO)₃Mn(μ‐TePh)₃Fe(CO)₃. Addition of fac‐[Fe(CO)₃(TePh)₃]^? to the CpNi(I)(PPh₃) in THF resulted in formation of the neutral CpNi(TePh)(PPh₃) also obtained from reaction of CpNi(I)(PPh₃) and [Na][TePh] in MeOH. This investigation shows that fac‐[Fe(CO)₃(TePh)₃]^? serves as a tridentate metallo ligand and tellurolate ligand‐transfer reagent. The study also indicated that the fac‐[Fe(CO)₃(SePh)₃]^? may serve as a better tridentate metallo ligand and chalcogenolate ligand‐transfer reagent than fac‐[Fe(CO)₃(TePh)₃]^? in the syntheses of heterometallic chalcogenolate complexes.     

Synthese und Struktur von [Fe6(CO)12(TePh)12]

Synthesis and Structure of [Fe₆(CO)₁₂(TePh)₁₂] The reaction of [Fe(CO)₄(HgCl)₂] with PhTeSiMe₃ leads to the formation of red needles. [Fe₆(CO)₁₂(TePh)₁₂] was characterised by single crystal x‐ray structure analysis. In this compound each iron atom is coordinated octahedrally by four μ₂‐TePh groups and two terminal CO groups. The iron atoms form a six membered planar ring.     

Syntheses and Characterization of Manganese-Tellurolate Complexes by Using Chelating Metalloligand cis-[Mn(Co)4(TePh)2]− and Potential Electrophilic TeMe+ Reagent

The cis-[Mn(CO)₄(TePh)₂]^?, similar to bidentate ligand PhTe(CH₂)₃TePh, acts as a “chelating metalloligand” for the synthesis of metallic tellurolate compounds. The reaction of cis[Mn(CO)₄(TePh)₂]^? with BrMn(CO)₅ in THF leads to a mixture of products[(CO)₃,BrMn(μ-TePh)₂Mn(CO)₄]^? (1) and Mn₂(μ-TePh)₂(CO)_g (2). Complex 1 crystallizes in the triclinic space group Pl? with a = 11.309(3) Å, b = 14.780(5) Å, c = 19.212(6) Å, a = 76.05(3)° β = 72.31(3)°, γ = 70.41(3)° V = 2848(2) Å₃, Z = 2. Final R = 0.034 and R_w = 0.035 resulting from refinement of 10021 total reflections with 677 parameters, Dropwise addition of (MeTe)₂ to a solution of [Me₃O][BF₄] in CH₃CN leads to formation of [Me₂TeTeMe][BF₄], a potential MeTe⁺ donor ligand. In contrast to oxidative addition of diphenyl ditelluride to [Mn(CO)s]^? to give cis-[Mn(CO)₄(TePh)₂]^? which was thermally transformed into [(CO)₃Mn(μ-TePh)₃Mn(CO)₃]^?, reaction of [Mn(CO)₅]^?with [Me₂TeTeMe]⁺ proceeded to give the monomeric species MeTeMn(CO)₅ as initial product which was then dimerized into Mn₂(μ-TeMe)₂(CO)_g (4).     

Structure and Reactivity of Iron(0)-Phenyltellurolate [PPN][PhTeFe(CO)4]

Anionic iron(0) tetracarbonyl with terminal phenyltellurolate ligand PhTe^?, [PhTeFe(CO)₄]^?, has been synthesized and characterized. The title compound was obtained by addition of (PhTe)₂ to [PPN][HFe(CO)₄] THF solution dropwise. [PPN][PhTeFe(CO)₄] crystallizes in the monoclinic space group C c, with a = 16.119(4) Å, b = 13.141(3) Å, c = 19.880(8) Å, β = 93.04(3)°, V = 4205(2) ų, and Z = 4. The [PhTeFe(CO)₄]^? anion is a trigonal-bipyramidal complex in which the phenyltellurolate ligand occupies an axial position with Fe-Te bond length 2.630(5) Å and the Fe-Te-C(Ph) angle is 103.4(5)°. The neutral iron(0)-telluroether compound, (PhTeMe)Fe(CO)₄, was prepared by alkylation of the [PhTeFe(CO)₄]^?. Protonation of [PhTeFe(CO)₄]^?and reaction of H₂Fe(CO)₄ and PhTe)₂ ultimately lead to formation of the known dimer Fe₂(μ-TePh)₂(CO)₆ and H₂.     

Synthesis and molecular structures of heterometallic complexes [RC5H4Fe(CO)2]2 Sn(TePh)2 and their adducts with chromium and tungsten carbonyls or with trimethylplatinum iodide

Complexes [RC₅H₄Fe(CO)₂]₂Sn(TePh)₂ (R=H, Me) containing stable heterometallic Fe−Sn−Fe fragments with two phenyltellurium groups at the tin atom were synthesized from [RC₅H₄Fe(CO)₂]₂SnCl₂ (R=H, Me) and sodium phenyltelluride and their structures were established by X-ray analysis. Their chelates with tungsten tetracarbonyl, [RC₅H₄Fe(CO)₂]₂Sn(TePh)₂[W(CO)₄] (R=Me, H), and complexes with two Cr(CO)₅ fragments or dimeric trimethylplatinum iodide were synthesized and studied by X-ray analysis. Thermal decomposition of [RC₅H₄Fe(CO)₂]₂Sn(TePh)₂ complexes and their adducts with ML fragments (ML=W(CO)₄, 2 Cr(CO)₅, (Me₃PtI)₂) into inorganic tellurides of a preset mixed-metal—chalcogenide composition was studied by differential scanning calorimetry. The temperature of complete elimination of organic fragments from methylcyclopentadienyl complexes is about 100°C lower than in the case of cyclopentadienyl analogs. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1766–1772, September, 1999.     

Photoassisted synthesis of mixed-metal clusters: [PPN] [CoOs3(CO)13], H2RuOs3(CO)13, and H2FeOs3(CO)13

The utility of photochemical methods for the directed synthesis of mixed-metal metal clusters has been explored. The 366 nm photolysis of a solution containing [PPN] [Co(CO)₄] (PPN = (Ph₃P)₂N⁺) and Os₃(CO)₁₂ gives the new cluster [PPN][CoOs₃(CO)₁₃] in 33% yield. Irradiation of a mixture of Fe(CO)₅ and H₂Os₃(CO)₁₀ yields H₂FeOs₃(CO)₁₃ in 95% yield, and photolysis of Ru₃(CO)₁₂ in the presence of H₂Os₃(CO)₁₀ gives the new cluster H₂RuOs₃(CO)₁₃. Details of these syntheses, their probable mechanisms, and the characterization of the new compounds are discussed.     

Oxidative Addition of Diphenyl Disulfide/Thiophenol to [Mn(CO)5]−: Crystal Structure of cis-[Mn(CO)4(SPh)2]−

Oxidative addition of diphenyl disulfide to the coordinatively unsaturated [Mn(CO)₅]^? led to the formation of low-spin, six-coordinate cis-[Mn(CO)₄(SPh)₂]^?. The complex cis-[PPN][Mn(CO)₄(SPh)₂] crystallized in monoclinic space group P2₁/c with a = 9.965(2) Å, b = 24.604(5) Å, c = 19.291(4) Å, β = 100.05(2)°, V = 4657(2)ų, and Z = 4; final R = 0.036 and R_w = 0.039. Thermal transformation of cis-[Mn(CO)₄(SPh)₂]^? to [(CO)₃Mn(μ-SPh)₃Mn(CO)₃]^? was completed overnight in THF at room temperature. Additionally, reaction of [Mn(CO)₅]^? and PhSH in 1:2 mole ratio also led to cis-[PPN](Mn(CO)₄(SPh)₂]. Presumably, oxidative addition of PhSH to [Mn(CO)₄]^? was followed by a Lewis acid-base reaction to form cis-[Mn(CO)₄(SPh)₂]^? with evolution of H₂.     

Synthese gemischt chalkogenido‐verbrückter Dirheniumkomplexe vom Typ Re2(μ‐ER)(μ‐E′R′)(CO)8 (E,E′ = S,Se, Te; R,R′ = org. Rest)

Synthesis of Mixed Chalcogenido‐Bridged Dirhenium Complexes of the Type Re₂(μ‐ER)(μ‐E′R′)(CO)₈ (E, E′ = S, Se, Te; R, R′ = org. Residue) Hydrido sulfido bridged complexes Re₂(μ‐H)(μ‐SR)(CO)₈ (R = Ph, naph, Cy) react with the base DBU to give the salts [DBUH][Re₂(μ‐SR)(CO)₈]. Upon addition of electrophiles R′E′Br (E′R = SPh, SePh, TePh) to the in situ prepared salts mixed chalcogenido bridged complexes Re₂(μ‐SR)(μ‐E′R′)(CO)₈ were formed. The structures of the new compounds Re₂(μ‐SCy)(μ‐SePh)(CO)₈ and Re₂(μ‐Snaph)(μ‐TePh)(CO)₈ were determined by single crystal X‐ray analyses. For the preparation of analogous selenido tellurido bridged complexes Re₂(μ‐SePh)(μ‐TeR)(CO)₈ the novel hydrido selenido bridged complex Re₂(μ‐H)(μ‐SePh)(CO)₈ was prepared from Re₂(CO)₈(NCMe)₂ and PhSeH. Its structure was determined by single crystal X‐ray analysis. Subsequent deprotonation with DBU gave in situ [DBUH][Re₂(μ‐SePh)(CO)₈] which upon addition of RTeBr (R = Ph, Buⁿ, Bu^t) formed the desired complexes Re₂(μ‐SePh)(μ‐TeR)(CO)₈. The reaction with Bu^tTeBr also yielded the novel spirocyclic complex (μ₄‐Te){Re₂(μ‐SePh)(CO)₈}₂ in low amounts. It was identified by single crystal X‐ray analysis. Re₂(μ‐SePh)(μ‐TeBu^t)(CO)₈ is oxidised in chloroform in the presence of air to give the novel complex (μ‐Te–Te‐μ){Re₂(μ‐SePh)(CO)₈}₂. All mixed chalcogenido bridged dirhenium complexes were proved to be dynamic in solution by ¹³C NMR spectroscopy. The dynamic behaviour is based on the fast and permanent inversion of the sulfido and selenido bridges. The tellurido bridges are rigid on the time scale of ¹³C NMR spectroscopy.     

Nucleophilic attack on cluster-bound acetylide ligands derived from the iron ketenylidene, [Fe3(CO)9(CCO)]2−

Reaction of the iron ketenylidene (PPN)₂[Fe₃(CO)₉CCO] [PPN =bis (triphenylphosphine)nitrogen(+1)] with trifluoroacetic anhydride forms a highly electrophilic acetylide cluster (PPN)[Fe₃(CO)₉CCOC(O)CF₃] (lc), analogous to the known compounds (PPN)[Fe₃(CO)₉CCOR] [R=Et, (Ia); Ac, (Ib)] prepared from the reaction of ethyl triflate and acetyl chloride on the ketenylidene. Reaction of phosphines and (Ib, c) yield phosphonium acetylides [Fe₃(CO)₉CCPR₃] [(II),R=Ph], with loss of (PPN)[CH₃CO₂] or (PPN)[CF₃CO₂]. Additionally, (Ic) and triphenylarsine react to give an analogous arsonium acetylide [Fe₃(CO)₉CCAsPh₃] (III). No reaction occurs when an excess of arsine is added to (Ib). The reaction of (Ib, c) with anionic nucleophiles is reported, including reaction of Na[CpFe(CO)₂] and (Ib) to afford an unusual metallated acetylide cluster (PPN) [Fe₃(CO)₉CCFe(CO)₂Cp] (IV). Clusters (II), (III), and (IV) are spectroscopically characterized and a single crystal x-ray structure determination of (IV) is reported. (PPN)[Fe₃(CO)₉CCFe(CO)₂Cp] (IV) crystallizes in the monoclinic space group P2₁/n;a=17.793(2) Å;b=16.108(3) Å;c=18.157(3) Å;=107.62(1)⁰;V=4959(3) ų;Z=4. Refinement of 469 variables on 5981 observed [I>3(I)] reflections converged toR=3.5% andRw=4.7%.     

Übergangsmetall-Silyl-Komplexe, 44. Darstellung der zweikernigen Silyl-Komplexe (CO)3(R3Si)Fe(μ-PR′R′′)Pt(PPh3)2 durch oxidative Addition von (CO)3(R′R′′HP)Fe(H)SiR3 an (C2H4)Pt(PPh3)2

Transition Metal Silyl Complexes, 44. — Preparation of the Binuclear Silyl Complexes (CO)₃(R₃Si)Fe(μ-PR′R′′)Pt(PPh₃)₂ by Oxidative Addition of (CO)₃(R′R′′HP)Fe(H)SiR₃ to (C₂H₄)Pt(PPh₃)₂ The complexes (CO)₃(R′R′′HP)Fe(H)SiR₃ ( 1 ) [PHR′R′′ = PHPh₂, PH₂Ph, PH₂Cy; SiR₃ = SiPh₃, SiPh₂Me, SiPhMe₂, Si(OMe)₃] react with Pt(C₂H₄)(PPh₃)₂ to give the dinuclear, silyl-substituted complexes (CO)₃(R₃Si)Fe(μ-PR′R′′)Pt(PPh₃)₂ ( 2 ) in high yields. Upon reaction of 2 (R = R′ R′′ = Ph) with CO, the PPh₃ ligand at Pt being trans to the PPh₂ bridge is exchanged, and (CO)₃(Ph₃Si)Fe(μ-PPh₂)Pt(PPh₃)CO ( 3 ) is formed. Complex 3 is characterized by an X-ray structure analysis. The rather short Fe — Si distance [233.9(2) pm] and the infrared spectrum of 3 indicate that the Fe — Pt bond is quite polar.     

Reaction Behavior of Decacarbonyldimetalates(2‐) (M = Cr and Mo) towards the Nitrosyl Carbonyls of Iron and Cobalt

The reaction of the nitrosyl carbonyl complexes [Fe(NO)₂(CO)₂] and [Co(NO)(CO)₃] with the decacarbonyldimetalates [M₂(CO)₁₀]^2– (M = Cr and Mo) in THF as the solvent at room temperature was investigated. Thereby a substitution of one nitrosyl ligand towards carbon monoxide was observed in each case. Both reactions afforded the known metalate complexes [Fe(NO)(CO)₃]^– and [Co(CO)₄]^–, respectively. These species were isolated as their corresponding PPN salts [PPN⁺ = bis(triphenylphosphane)iminium cation] in nearly quantitative yields. The products were unambiguously identified by their IR spectroscopic and elemental analytic data as well as by their characteristic colors and melting points.     

Zinkselenid- und Zinktelluridcluster mit Phenylselenolat- und Phenyltellurolatliganden. Die Kristallstrukturen von [NEt4]2[Zn4Cl4(SePh)6], [NEt4]2[Zn8Cl4Se(SePh)12], [Zn8Se(SePh)14(PnPr3)2], [HPnPr2R]2[Zn8Cl4Te(TePh)12] (R = nPr,Ph) und [Zn10Te4(TePh)12(PR3)2] (R = nPr,Ph)

Zincselenide- and Zinctellurideclusters with Phenylselenolate- and Phenyltellurolateligands. The Crystal Structures of [NEt₄]₂[Zn₄Cl₄(SePh)₆], [NEt₄]₂[Zn₈Cl₄Se(SePh)₁₂], [Zn₈Se(SePh)₁₄(PⁿPr₃)₂], [HPⁿPr₂R]₂[Zn₈Cl₄Te(TePh)₁₂] (R = ⁿPr, Ph), and [Zn₁₀Te₄(TePh)₁₂(PR₃)₂] (R = ⁿPr, Ph) In the prescence of NEt₄Cl ZnCl₂ reacts with PhSeSiMe₃ or a mixture of PhSeSiMe₃/Se(SiMe₃)₂ to form the ionic complexes [NEt₄]₂[Zn₄Cl₄(SePh)₆] 1 or [NEt₄]₂[Zn₈Cl₄Se(SePh)₁₂] 2 respectively. The use of PⁿPr₃ instead of the quarternary ammonia salt leads in toluene to the formation of crystalline [Zn₈Se(SePh)₁₄(PⁿPr₃)₂] 3 . Reactions of ZnCl₂ with PhTeSiMe₃ and tertiary phosphines result in acetone in crystallisation of the ionic clusters [HPⁿPr₂R]₂[Zn₈Cl₄Te(TePh)₁₂] (R = ⁿPr 4 , Ph 5 ) and in THF of the uncharged [Zn₁₀Te₄(TePh)₁₂(PR₃)₂] (R = ⁿPr 6 , Ph 7 ). The structures of 1–7 were obtained by X-ray single crystal structure. ( 1 : space group P2₁/n (No. 14), Z = 4, a = 1212,4(2) pm, b = 3726,1(8) pm, c = 1379,4(3) pm β = 99,83(3)°; 2 space group P2₁/c (Nr. 14), Z = 4, a = 3848,6(8) pm, b = 1784,9(4) pm, c = 3432,0(7) pm, β = 97,78(3)°; 3 : space group Pnn2 (No. 34), Z = 2, a = 2027,8(4) pm, b = 2162,3(4) pm, c = 1668,5(3) pm; 4 : space group P2₁/c (No. 14), Z = 4, a = 1899,8(4) pm, b = 2227,0(5) pm, c = 2939,0(6) pm, β = 101,35(3)°; 5 : space group space group P2₁/n (No. 14), Z = 4, a = 2231,0(5) pm, b = 1919,9(4) pm, c = 3139,5(6) pm, β = 109,97(4)°; 6 : space group I4₁/a (No. 88), Z = 4, a = b = 2566,0(4) pm, c = 2130,1(4) pm; 7 : space group P1¯ (No. 2), Z = 2, a = 2068,4(4) pm, b = 2187,8(4) pm, c = 2351,5(5) pm, α = 70,36°, β = 84,62°, γ( = 63,63°)     

Reactivity of Cyanide and Thiocyanate Towards the Nitrosyl Carbonyl [Co(CO)3(NO)]

The reaction of equimolar amounts of [Co(CO)₃(NO)] and [PPN]CN, PPN⁺ = (PPh₃)₂N⁺, in THF at room temperature resulted in ligand substitution of a carbonyl towards the cyanido ligand presumably affording the complex salt PPN[Co(CO)₂(NO)(CN)] as a reactive intermediate species which could not be isolated. Applying the synthetic protocol using the nitrosyl carbonyl in excess, the title reaction afforded unexpectedly the novel complex salt PPN[Co₂(μ-CN)(CO)₄(NO)₂] ( 1 ) in high yield. Because of many disorder phenomena in crystals of 1 the corresponding NBu₄⁺ salt of 1 has been prepared and the molecular structure of the dinuclear metal core in NnBu₄[Co₂(μ-CN)(CO)₄(NO)₂] ( 2 ) was determined by X-ray crystal diffraction in a more satisfactory manner. In contrast to the former result, the reaction of [PPN]SCN with [Co(CO)₃(NO)] yielded the mononuclear complex salt PPN[Co(CO)₂(NO)(SCN-κN)] ( 3 ) in good yield whose molecular structure in the solid was even determined and its composition additionally confirmed by spectroscopic means.     

(Carbonyl)Iron‐Selenolates: New Synthetic Methods and Reactions with Electrophiles. Crystal Structures of [(CO)6Fe2(μ‐SeR)2]; R = Me3SiCH2 and p‐O2NC6H4CH2, {(CO)6Fe2[μ‐η2‐Se,Se′‐o‐(SeCH2C6H4CH2Se)]}, and [(CO)6Fe2(μ‐SeFe(CO)2cp)2]

The reactions of Fe(CO)₅ or Fe₃(CO)₁₂ with NaBEt₃H or KB[CH(CH₃)C₂H₅]₃H, respectively and treatment of the resulting carbonylates M₂Fe(CO)₄, M = Na, K with elemental selenium in appropriate ratios lead to the formation of M₂[Fe₂(CO)₆(μ‐Se)₂]. Subsequent reactions with organo halides or the complex fragment cpFe(CO)₂⁺, cp = η⁵‐C₅H₅ afforded the selenolato complexes [Fe₂(CO)₆(μ‐SeR)₂], R = CH₂SiMe₃ ( 1 ), CH₂Ph ( 2 ), p‐CH₂C₆H₄NO₂ ( 3 ), o‐CH₂C₆H₄CH₂ ( 4 ) and cpFe(CO)₂⁺ ( 5 ) in moderate to good yields. A similar reaction employing Ru₃(CO)₁₂, Se and p‐O₂NC₆H₄CH₂Br leads to the formation of the corresponding organic diselenide. The X‐ray structures of 1 , 3 , 4 and 5 were determined and revealed butterfly structures of the Fe₂Se₂ cores. The substituents in 1 , 3  and 5 adopt different conformations depending on their steric demand. In 4 , the conformation is fixed because of the chelate effect of the ligand. The Fe–Se bond lengths lie in the range 235 to 240 pm, with corresponding Fe–Fe bond lengths of 254 to 256 pm. The ⁷⁷Se NMR data of the new complexes are discussed and compared with the corresponding data of related complexes.     

{1,1′‐(Dimethylsilylene)bis[methanechalcogenolato]}diiron Complexes [2Fe2E(Si)] (E=S,Se, Te) – [FeFe] Hydrogenase Models

(Bis‐selenolato) and (bis‐tellurolato)diiron complexes [2Fe2E(Si)] were prepared and compared with the known (bis‐thiolato)diiron complex A to assess their ability to produce hydrogen from protons. Treatment of [Fe₃(CO)₁₂] with 4,4‐dimethyl‐1,2,4‐diselenasilolane ( 1 ) in boiling toluene afforded hexacarbonyl{μ‐{[1,1′‐(dimethylsilylene)bis[methaneselenolato‐κSe : κSe]](2 ?)}}diiron(Fe? Fe) ( 2 ). The analog bis‐tellurolato complex hexacarbonyl{μ‐{[1,1′‐(dimethylsilylene)bis[methanetellurolato‐κTe : κTe]](2 ?)}}diiron(Fe? Fe) ( 3 ) was obtained by treatment of [Fe₃(CO)₁₂] with dimethylbis(tellurocyanatomethyl)dimethylsilane, which was prepared in situ. All compounds were characterized by NMR, IR spectroscopy, mass spectrometry, elemental analysis and single‐crystal X‐ray analysis. The electrocatalytic properties of the [2Fe2X(Si)] (X=S, Se, Te) model complexes A, 1 , and 2 towards hydrogen formation were evaluated.     

Reaktionen von Cyclostibanen (RSb)n [R = (Me3Si)2CH,n = 3; Me3CCH2, n = 4, 5] mit den Übergangsmetallcarbonyl‐Komplexen [W(CO)5(thf)], [CpxMn(CO)2(thf)], [CpxCr(CO)3]2 und [Co2(CO)8]; Cpx = MeC5H4

Reactions of Cyclostibanes, (RSb)_n [R = (Me₃Si)₂CH, n = 3; Me₃CCH₂, n = 4, 5] with the Transition Metal Carbonyl Complexes [W(CO)₅(thf)], [Cp^xMn(CO)₂(thf)], [Cp^xCr(CO)₃]₂, and [Co₂(CO)₈]; Cp^x = MeC₅H₄ (RSb)₃ [R = (Me₃Si)₂CH] reacts with [W(CO)₅(thf)], [Cp^xMn(CO)₂(thf)], or [Co₂(CO)₈] to give [(RSb)₃W(CO)₅] ( 1 ), [RSb{Mn(CO)₂Cp^x}₂] ( 2 ) or [RSbCo(CO)₃]₂ ( 3 ). The reaction of (R′Sb)_n (n = 4, 5; R′ = Me₃CCH₂) with [Cp^xCr(CO)₃]₂ leads to [(R′Sb)₄{Cr(CO)₂Cp^x}₂] ( 4 ); Cp^x = MeC₅H₄, thf = Tetrahydrofuran.     

Reactions of RSe− (R = Me,Ph) Groups in [RSeFe(CO)4I and [RSeCr(CO)5−]

The anionic [MeSeFe(CO)₄] and [MeSeCr(CO)₅] complexes were synthesized by reaction of [PPN][HFe(CO)₄] and [PPN][HCr(CO)₅] with MeSeSeMe respectively via nucleophilic cleavage of the Se-Se bond. The ease of cleavage of the Se-Se bond follows the nucleophilic strength of metal-hydride complexes. Methylation of [RSeCr(CO)₅^?] by the soft alkylating agent MeI resulted in the formation of neutral (MeSeMe)Cr(CO)₅ in THF at 0°C. In contrast, the [ICr(CO)₅^?] was isolated at ambient temperature. Reaction of [MeSeFe(CO)₄^?] or [MeSeCr(CO)₅^?] with HBF₄ yielded (CO)₃Fc(μ-SeMe)₂Fe(CO)₃ dimer and anionic [(CO )₅Cr (μ-SeMe)Cr(CO)₅^?] respectively, and no neutral (HSeMe)Fe(CO)₄ and (HSeMe)Cr(CO)₅ were detected spectrally (IR) even at low temperature. Reaction of NOBF₄ or [Ph₃C][BF₄] and [MeSeCr(CO)₅^?] resulted in the neutral monodentate (MeSeSeMe)Cr(CO)₅ complex. Addition of 1 equiv CpFe(CO)₂I to 2 equiv [MeSeCr(CO)₅^?] gave CpFe(CO)₂(SeMe) and the anionic [(CO)₅Cr(μ-SeMe)Cr(CO)₅^?] in THF at ambient temperature.     

Komplexe mit Antimon‐Liganden: [tBu2(Cl)SbW(CO)5], [tBu2(OH)SbW(CO)5], O[SbPh2W(CO)5]2, E[SbMe2W(CO)5]2 (E = Se,Te), cis‐[(Me2SbSeSbMe2)2Cr(CO)4]

Complexes Containing Antimony Ligands: [^tBu₂(Cl)SbW(CO)₅], [^tBu₂(OH)SbW(CO)₅], O[SbPh₂W(CO)₅]₂, E[SbMe₂W(CO)₅]₂ (E = Se, Te), cis‐[(Me₂SbSeSbMe₂)₂Cr(CO)₄] Syntheses of [^tBu₂(Cl)SbW(CO)₅] ( 1 ), [^tBu₂(OH)SbW(CO)₅] ( 2 ), O[SbPh₂W(CO)₅]₂ ( 3 ), Se[SbMe₂W(CO)₅]₂ ( 4 ), cis‐[(Me₂SbSeSbMe₂)₂Cr(CO)₄] ( 5 ) Te[SbMe₂W(CO)₅]₂ ( 6 ) and crystal structures of 1 – 5 are reported.     

Insertion Reactions of [ReH(CO)5–n(PMe3)n] Complexes (n = 2–4) with aldehydes,CO2, and activated acetylenes

The complexes of the type [ReH(CO)_5–n(PMe₃)_n] (n = 4, 3) were reacted with aldehydes, CO₂, and RC?CCOOMe (R = H, Me) to establish a phosphine-substitutional effect on the reactivity of the Re–H bond. In the series 1–3 , benzaldehyde showed conversion with only 3 to afford a (benzyloxy)carbonyltetrakis(trimethylphosphine)rhenium complex 4 . Pyridine-2-carbaldehyde allowed reaction with all hydrides 1–3 . With 1 and 2 , the same dicarbonyl[(pyridin-2-yl)methoxy-O, N]bis(trimethylphosphine)rhenium 5b was formed with the intermediacy of a [(pyridin-2-yl)methoxy-O]-ligated species and extrusion of CO or PMe₃, respectively. The analogous conversion of 3 afforded the carbonyl[(pyridin-2-yl)methoxy-O,N]tris(trimethylphosphine)rhenium ( 1 ) 7b . While 1 did not react with CO₂, 2 and 3 yielded under relatively mild conditions the formato-ligated [Re(HCO₂)(CO)(L)(PMe₃)₃] species ( 8 (L = CO) and 9 (L = PMe₃)). Methyl propiolate and methyl butynoate were transformed, in the presence of 1 , to [Re{C(CO₂Me)?CHR}(CO)₃(PMe₃)₂] systems ( 10a (R = H), and 10b (R = Me)), with prevailing α-metallation and trans-insertion stereochemistry. Similarly, HC≡CCO₂Me afforded with 2 and 3 , the α-metallation products [Re{C(CO₂Me)?CH₂}(CO)(L)(PMe₃)₃] 11 (L = CO) and 12 (L = PMe₃). The methyl butyonate insertion into 2 resulted in formation of a mixture of the (Z)- and (E)-isomers of [Re{C(CO₂Me)?CHMe} (CO)₂(PMe₃)₃] ( 13a , b ). In the case of the conversion of 3 with MeC?CCO₂Me, a Re–H cis-addition product [Re{(E)-C(CO₂Me)?CHMe}(CO)(PMe₃)₄] ( 14 ) was selectively obtained. Complex 11 was characterized by an X-ray crystal-structure analysis.