The reaction of [Fe2(η-C5H5)2(CO)2(CNMe){CN(Me)H}]+ with AgI salts. Anion control of the reaction products

The reactions of equimolar amounts of [Fe₂(η-C₅H₅)₂(CO)₂(CNMe){CN(Me)H}]X and AgY in methanol results in a two-electron oxidation of [Fe₂(η-C₅H₅)₂(CO)₂(CNMe)₂] to give [Fe(η-C₅H₅)(CO)(CNMe)₂]BF₄ when either X⁻ or Y⁻ are the non-coordinating anion BF⁻₄, but [Fe(η-C₅H₅(CO)(CNMe)X] and [Fe(η-C₅H₅(CO)(CNMe)Y] when both X⁻ and Y⁻ are potentially coordinating anions such as NO₃⁻, Br⁻ or I⁻.     

Photochemical reactions of cationic isocyanide/carbonyl complexes of iron with selected nucleophiles

Photolysis of (η⁵-C₅H₅Fe(CO)(CNMe)₂]PF₆ in the presence of excess nucleophiles resulted in efficient substitution of the carbonyl ligand, generating the new isocyanide complexes (η⁵-C₅H₅Fe(CNMe)₂)(L)]PF₆ (L = PPh₃, AsPh₃, SbPh₃, pyridine, acetonitrile, and ethylene). Similar reactions of (η⁵-C₅H₅Fe(CO)_2)(CNMe)PF₆ led to sequential replacement of both carbony groups with the exception of L  ethylene. No evidence of photochemical isocyanide substitution was found. The same carbonyl complexes failed to reach with L thermally. In the absence of light, ethylene, pyridine, and acetonitrile complexes were found to disporportionate in the manner [η⁵-C₅H₅Fe(CNMe)(L)₂]PF₆→ [η⁵C₅H₅Fe(CNMe)₂(L)]PF₆ → [η⁵-C₅H₅Fe(CNMe)₃]PF₆ with the first rearrangement occurring much faster than the second. The new isocyanide complexes are characterized by their infrared and NMR (¹H, ¹³C) spectra.     

The reactions of AgY salts with [Fe2(η-C5H5)2(CO)4-n(CNMe)n] complexes (Y−  NO3−, BF4− or PF6−; n  0, 1 or 2). The crystal structure of [Fe(η-C5H5)2(CNMe)]BF4

The oxidative cleavage of [Fe₂(η-C₅H₅)₂(CO)_4-n(CNMe)_n] (n=0−2) by 2AgX gives mononuclear products. It is shown to be a two-electron process in most solvents but a one-electron process in acetonitrile. The two-electron oxidations proceed by way of adducts such as [Fe₂(η-C₅H₅)₂(CO)(CNMe)(μ-CO){;μ-CN(Me)AgPPh₃};]BF₄ which are isolable when n = 2, detectable when n = 1 and postulatetd when n = 0. The one-electron process gives no adducts, and 1AgX cleaves all of the substrate to [Fe(η-C₅H₅)(CO)(L)(NCMe)]⁺ and [Fe(η-C₅H₅)(CO)(L)]^. (L  CO or CNME). The latter may combine or react with added CHBr₃ to give [Fe(η-C₅H₅)(CO)(L)Br]. The structure of [Fe(η-C₅H₅)(CO)₂-(CNMe)]BF₄ has been determined by X-ray diffraction.     

Derivate des borols: IX. (η5-borol)metall-komplexe von ruthenium,osmium und rhodium

Dehydrogenating complexation of borolenes with carbonyls (Ru₃(CO)₁₂, Os₃(CO)₁₂), Wilkinson's catalyst (RhCl(PPh₃)₃) and related compounds (RuCl₂(PPh₃)₃, RuHCl(PPh₃)₃, OSCl₂(PPh₃)₃), and (η⁶-arene)ruthenium complexes (Ru(η-C₆H₆)(η⁴-C₆H₈), [Ru(η-C₆H₆)Cl₂]₂, [Ru(η-C₆-Me₆)Cl₂]₂) leads to the (η⁵-borole)metal complexes of Ru, Os, and Rh. Inter alia, the preparation of the complexes Ru(CO)₃(η⁵-C₄H₄BF) (R = Ph, OMe, Me), Os(CO)₃L (L = η⁵-C₄H₄BPh), MHClL(PPh₃)₂ (M = Ru, Os), RhClL(PPh₃)₂, and RuL(η-C₆R₆) (R = H, Me) is described. The structures of RuHClL(PPh₃)₂ and RhClL(PPh₃)₂ have been determined by X-ray diffraction analysis.     

The reactions of AgI electrophile with [Fe2(η-C5H5)2(CO)2(L){CN(Me)H}]+ and [Fe2(η-C5H5)2(CO)2{CN(Me)H}2]2+ salts (L = CO or CNMe)

The protonated species [Fe₂(η-C₅H₅)₂(CO)₂(η-CO){μ-CN(Me)H}]X, [Fe₂(η-C₅H₅)₂(CO)(CNMe)(μ-CO){μ-CN(Me)H}][X], and [Fe₂(η-C₅H₅)₂(CO)₂{η-CN(Me)H}₂][X]₂ react with one equivalent of AgY. The Ag⁺ and one H⁺ act together as a two-electron oxidant. Silver metal is precipitated quantitatively and the substrates cleaved to give mono-nuclear products of the type (a) [Fe(η-C₅H₅)(CO)(L)X] and [Fe(η-C₅H₅(CO)(L)Y] or (b) Fe(η-C₅H₅(CO)(L)(CNMe)][X] (L = CO, CNMe). If X⁻ and Y⁻ are both coordinating anions such as NO₃⁻, I⁻, or Br⁻ or the solvent is MeCN products of type (a) are usually obtained with X = Y = MeCN⁺ if acetonitrile is used as the solvent. However, if either X⁻ or Y⁻ is a non-coordinating anion such as BF₄⁻ or PF₆⁻ and methanol is the solvent, the products are usually those of type (b). When X⁻ = [p-MeC₆H₄SO₃]⁻, both types of products are obtained in significant amounts. If two equivalents of Ph₃P are added to the methanol solution of [Fe₂(η-C₅H₅)₂(CO)₂{-CN(Me)H}₂[BF₆]₂, no reaction takes place until the third equivalent of AgNO₃ has been added. The products have been isolated and characterized by analysis and infrared spectroscopy. The previously unreported [Fe₂(η-C₅H₅)₂(CO)(CNMe)(η-CO){η-CN(Me)H}] X salts are described for X⁻ = BF₄⁻, PF₆⁻, Br⁻ · 2H₂O, I⁻ · H₂O, NO₃⁻ · 0.5H₂O, and p-MeC₆H⁴SO₃⁻.     

The reactions of [Fe2(η-C5H5)2(CO)4−n(CNMe)n] (n = 0–4) complexes with halogens and mercury(II) salts

Halogens, X₂, and HgY₂ (X = Cl, Br, I; Y = X, F, NO₃, BF₄) cleave the metalmetal bonds in [Fe₂(η-C₅H₅)₂(CO)_4−n(CNMe)_n] complexes (n = 0–4). Typically, e.g., when n = 2, X₂ electrophiles give [Fe(η-C₅H₅)(CO)(CNMe)X] (a) and [Fe(η-C₅H₅)(CO)(CNMe)₂]X (b) in relative yields which depend on X, the reaction solvent and n, but HgY₂ give equimolar amounts of [Fe(η-C₅H₅)(CNMe)₂Y] (c and [Fe(η-C₅H₅)(CO)₂HgY] only. Hg(CN)₂ reacts more slowly than other HgY₂, and [Hg(PPh₃)₂I₂] does not react at all. It is suggested that the reactions which give rise to products of type (a), (b) or (c) are all two-electron oxidation which proceed by way of adducts containing μ-CA → X₂ or μ-CA → HgX₂ groups (Ca = CO or CNMe). One of these adducts has been isolated, namely [Fe₂(η-C₅H₅)₂(CNMe)₂{μ-CN(Me)HgCl₂}₂] · CHCl₃.     

Regiospecificity in the reaction of [Fe2(η-C5H5)2(CO)4-n(CNMe)n] (n  02) with mercury(II) halides

The reactions of [Fe₂(η-C₅H₅)₂(CO)₂(L)(CNMe)] (L  CO or CNME) with HgX₂ (X  Cl, Br or I) give [Fe(η-C₅H₅)(CO)₂HgX] and [Fe(η-C₅H₅)(L)-(CNMe)X] as the sole products in ca. quantitative yields; this is consistent with the previously proposed mechanism for the reactions of electrophiles with polynuclear metal carbonyl derivatives.     

Synthese d'une phosphine contenant du titane(II), (η5-C5H5)[η7-C7H6P(C6H5)2]Ti,ET DEcomplexes heterobimetalliques

Reaction of chlorodiphenylphosphine with (η⁵-C₅H₅)(η⁷-C₇H₆Li)Ti gave (η⁵-C₅H₅)[η⁷-C₇H₆P(C₆H₅)₂]Ti in good yields. This novel phosphinetitanium (II) derivative displaced one carbonyl of metal carbonyl complexes [Ni(CO)₄, Fe(CO)₅ and Mo(CO)₆] to afford heterobimetallic complexes containing low valent titanium, and behaved as a poor electron-donating phosphine.     

Use of the Cationic Fragments [Ru(η5-C5H5) (MeCN)3]+ and [M(η6-C6H5R)(MeCN)3]+ (M=Os, Ru; R=H, Me) as Ionic Coupling Reagents in the Synthesis of the Clusters [Os4M2(CO)12(η6-C6H5R)], [Os4M(CO)12(η6-C6H6)(Au2dppm)] and [Os5Ru(CO)15(η5-C5H5)(AuPPh3)]*

The clusters [H₂Os₄M(CO)₁₂eta⁶-C₆H₆)] (M=Os, Ru) may be deprotonated to generate anions [Os₄M(CO)₁₂eta⁶-C₆H₆)]^2- which react with [M′eta⁶-C₆H₅R) (MeCN)₃]²⁺(M^′=Os, Ru; R=H, Me) to give the bicapped tetrahedral clusters [Os₄(CO)₁₂MM′eta⁶-C₆H₅R)₂]. Whereas [Os₄(CO)₁₂M₂eta⁶-C₆H₆)₂] (M=Os, Ru) have one Meta⁶-C₆H₆) unit in a site connected to three other metals, {3}, and one in a site connected to four other metals, {4}, [Os₄(CO)₁₂OsRueta⁶-C₆H₆)₂] has the Rueta⁶-C₆H₆) unit in the {3} site irrespective of whether the Os or Ru anion is capped. Coupling of these anions with Au₂dppm yields [Os₄M(CO)₁₂eta⁶-C₆H₆)(Au₂dppm)] (M=Os, Ru), which have the arene ligand in the axial site of a trigonal bipyramid and the digold unit capping two faces. Reduction of [H₂Os₅(CO)₁₅] with K/Ph₂CO and coupling with [Rueta⁵-C₅H₅)(MeCN)₃]²⁺yields the monoanion [Os₅(CO)₁₅Rueta⁵-C₅H₅)]^? which reacts with [AuPPh₃]⁺ generating [Os₅(CO)₁₅Rueta⁵-C₅H₅)(AuPPh₃)] with the “Ru(C₅H₅)” unit in the terminal {3} site.     

Di- and poly-nuclear transition metal complexes as catalysts for the metal carbonyl substitution reaction. The role of supported metals and metal oxides as catalyst promoters

Various di- and poly-nuclear transition metal complexes have been investigated as catalysts for the metal carbonyl substitution reaction. The complexes [{(η⁵-C₅H₄R)Fe(CO)₂} ₂] (R = H, Me, CO₂Me, OMe, O(CH₂)₄OH) and [{(η⁵-C₅H₅)-Ru(CO)₂} ₂] are active catalysts for a range of substitution reactions including the probe reaction [Fe(CO)₄(CNBu^t)] + Bu^tNC → [Fe(CO)₃(CNBu^t)₂] + CO. [{(η⁵-C₅Me₅)Fe(CO)₂}₂] is catalytically active only on irradiation with visible light. For [{η⁵-C₅H₅)Fe(CO)₂}₂] and a range ofisocyanides RNC ( R = Bu^t, C₆H₅CH₂, 2,6-Me₂C₆H₃), catalyst modification by substitution with isocyanide is a major factor influencing the degree of the catalytic effects observed, e.g. [{(η⁵-C₅H₅)Fe(CO)(CNBu^t)}₂] is approximately 35 times as active as [(η⁵-C₅H₅)₂FE₂(CO)₃(CNBu^t)] for the [Fe(CO)₄(CNBu^t)] → [Fe(CO)₃(CNBu^t)₂] conversion. Mechanistic studies on this system suggest that the catalytic substitution step probably involves a rapid intermolecular attack of isonitrile, possibly on a labile catalyst-substrate radical intermediate such as {[Fe(CO)₄(CNR)][(η⁵-C₅H₅)Fe(CO)₂]}; or on a reactive radical cation such as [Fe(CO)₄(CNR)]⁺ generated via electron transfer between the substrate and the catalyst. Other transition metal complexes which also catalyze the substitution of CO by isocyanide in [Fe(CO)₄(CNR)] (and [M(CO)₆] (M = Cr, Mo, W), [Mn₂(CO)₁₀], [Re₂(CO)₁₀]) include [Ru₃(CO)₁₂], [H₄Ru₄(CO)₁₂], [M₄(CO)₁₂] (M = Co, Ir) and [Co₂(CO)₈]. These reactions conform to the general mechanistic patterns established for [{(η⁵-C₅H₅)Fe(CO)₂}₂], suggesting a similar mechanism. A range of materials, notably PtO₂, PdO and Pd/C, act as promoters for the homogeneous di- and poly-nuclear transition metal catalysts, and can even be used to induce activity in normally inactive dimer and cluster complexes e.g. [Os₃(CO)₁₂]. This promotion is attributed to at least three possible effects: the removal of catalyst inhibitors, a catalyzed substitution of the homogeneous catalyst partner, and a possible homogeneous-heterogeneous interaction which promotes the formation of catalytic intermediates.     

Metallacyclic complexes with ortho-silylated triphenylphosphine ligands, LnOs(κ(Si,P)-SiMe2C6H4PPh2), derived from thermal reactions of the coordinatively unsaturated trimethylsilyl, methyl complex, Os(SiMe3)(Me)(CO)(PPh3)2

Reaction between Os(SiCl₃)Cl(CO)(PPh₃)₂ and five equivalents of MeLi produces a colourless intermediate, tentatively formulated as the lithium salt of the six-coordinate, dimethyl, trimethylsilyl-containing complex anion, Li[Os(SiMe₃)(Me)₂(CO)(PPh₃)₂]. Reaction of this material with ethanol releases methane and gives the red, coordinatively unsaturated methyl, trimethylsilyl-containing complex, Os(SiMe₃)(Me)(CO)(PPh₃)₂ (1). An alternative synthesis of 1 is to add one equivalent of MeLi to Os(SiMe₃)Cl(CO)(PPh₃)₂, which in turn is obtained by adding three equivalents of MeLi to Os(SiCl₃)Cl(CO)(PPh₃)₂. Treatment of 1 with p-tolyl lithium, again gives a colourless intermediate which may be Li[Os(SiMe₃)(Me)(p-tolyl)(CO)(PPh₃)₂], and reaction with ethanol gives the red complex, Os(SiMe₃)(p-tolyl)(CO)(PPh₃)₂ (3). Complexes 1 and 3 are readily carbonylated to Os(SiMe₃)(Me)(CO)₂(PPh₃)₂ (2) and Os(SiMe₃)(p-tolyl)(CO)₂(PPh₃)₂ (4), respectively. Heating Os(SiMe₃)Cl(CO)(PPh₃)₂ in molten triphenylphosphine results only in loss of the trimethylsilyl ligand and formation of the previously known complex containing an ortho-metallated triphenylphosphine ligand, Os(κ²(C,P)-C₆H₄PPh₂)Cl(CO)(PPh₃)₂. In contrast, heating the five-coordinate osmium-methyl complex, Os(SiMe₃)(Me)(CO)(PPh₃)₂ (1), in the presence of triphenylphosphine results mainly, not in tetramethylsilane elimination, but in ortho-silylation as well as ortho-metallation of different triphenylphosphine ligands giving, Os(κ²(Si,P)-SiMe₂C₆H₄PPh₂)(κ²(C,P)-C₆H₄PPh₂)(CO)(PPh₃) (5). A byproduct of this reaction is the non-silicon containing di-ortho-metallated complex, Os(κ²(C,P)-C₆H₄PPh₂)₂(CO)(PPh₃) (6). A similar reaction occurs when Os(SiMe₃)(Me)(CO)(PPh₃)₂ (1) is heated in the presence of tri(N-pyrrolyl)phosphine producing Os(κ²(Si,P)-SiMe₂C₆H₄PPh₂)(κ²(C,P)-C₆H₄PPh₂)(CO)[P(NC₄H₄)₃] (7) but a better synthesis of 7 is to treat 5 directly with tri(N-pyrrolyl)phosphine. Heating the six-coordinate complex, Os(SiMe₃)(Me)(CO)₂(PPh₃)₂ (2), gives two complexes both containing ortho-metallated triphenylphosphine, one with loss of the trimethylsilyl ligand, giving the known complex, Os(κ²(C,P)-C₆H₄PPh₂)H(CO)₂(PPh₃), and the other with retention of the trimethylsilyl ligand, giving Os(SiMe₃)(κ²(C,P)-C₆H₄PPh₂)(CO)₂(PPh₃) (8). Crystal structure determinations for 5, 6, 7 and 8 have been obtained.     

Photochemical reactions of allyl and crotyl halides with cyclopentadienyl-chromium, -molybdenum and -tungsten complexes

[MoCl(CO)₃(η⁵-C₅H₅)] on photolysis with allyl or crotyl halides C₅H₄RX gives Mo^IV complexes [MoX₂(CO)(η³-C₃H₄R)(η⁵-C₅H₅)] (R = H, X = Cl, Br, I; R = Me, X = Cl, Br). [WCl(CO)₃(η⁵-C₅H₅)] under similar conditions gives trihalides [WX₃(CO)₂(η⁵-C₅H₅)] (X = Cl, Br) on reaction with C₃H₅Cl and C₃H₅Br while [WCl(CO)₃(η⁵-C₅H₄SiMe₃)] and [CrI(CO)₃(η⁵-C₅H₅)] react with allyl chloride to give [WCl₃(CO)₂(η⁵-C₅H₄SiMe₃)] and [CrCl₂(η⁵-C₅H₅)] respectively.     

Die thermische reaktion von C5H5(CO)2FeNa mit benzimidchloriden C6H5(Cl)CNR

η⁵-C₅H₅(CO)₂FeNa reacts with the benzimide chlorides C₆H₅(Cl)CNR (R  CH(CH₃)₂, C₆H₅) in boiling THF to give the η¹-iminoacyl complexes η⁵-C₅H₅ (CO)₂Fe[η¹-C(C₆H₅)NR]. Alternatively, the new Fe complexes [η⁵-C₅H₅(CO)Fe$\text{C(C}{}_6\text{H}{}_5\text{)N(CH}{}_3\text{)C(C}{}_6\text{H}{}_5\text{)N}$CH₃PF₆ (IV) and [η⁵-C₅H₅(CO)₂FeC(C₆H₅)N(CH₃)C(C₆H₅)NCH₃]PF₆ (V) are formed under the same conditions, if R  CH₃. Hudrolysis of the CN single bond of the ligand in V, not stabilized by a chelate effects as in IV, results in the formation of [η⁵-C₅H₅(CO)₂FeC(C₆H₅)NHCH₃]PF₆ (VII). Reaction of η⁵-C₅H₅(CO)₂ with N-benyzylbenzimido chloride yields η⁵-C₅H₅(CO)₂FeCH₂C₆H₅ as the only isolated product.     

Reactions of transition metal σ-acetylide complexes: IX. Preparation and properties of some cycloheptatrienylvinylidene complexes

Addition of [C₇H₇][PF₆] to iron, ruthenium or osmium alkynyl complexes has given eight cationic cycloheptatrienylvinylidene derivatives [M{C C(C₇H₇)R}(L)₂ (η-C₅H₅)][PF₆] (M = Fe, Ru or Os; R = Me, Pr, Ph or C₆F₅; L = PPh₃, L₂ = dppm or dppe; but not all combinations). With Fe(C₂Ph)(CO)₂(η-C₅H₅), only [Fe(CO)₂(thf)(η-C₅H₅)][PF₆] was obtained. Reactions of the new complexes are characterised by loss of the C₇H₇ group. The NMR spectra and FAB mass spectra are described in detail.     

The tris(triphenylphosphine)osmium zerovalent complexes Os(CO)2(PPh3)3, .Os(CO)(CNR)(PPh3)3, Os(CO)(CS)(PPh3)3, Os(CS)(cNR)(PPh3)3 and derived compounds

Detailed procedures for the syntheses of Os(CO)₂(PPh₃)₃, Os(CO)(CNR)-(PPh₃)₃ (R = p-tolyl), Os(CO)(CS)(PPh₃)₃ and Os(CS)(CNR)(PPh₃)₃, together with the derived complexes Os(CO)₂(CS)(PPh₃)₂, Os(CO)(CS)(CNR)(PPh₃)₂, Os(η²-C₂H₄)(CO)(CNR)(PPh₃)₂, Os(η²-C₂H₄)(CO)(CS)(PPh₃)₂, Os(η²CS₂)(CO)₂-(PPh₃)₂, Os(η²CS₂)(CO)(CS)(PPh₃)₂, Os(η²-CS₂)(CO)(CNR)(PPh₃)₂, Os(η²PhC₂Ph)(CO)₂(PPh₃)₂ and OsH(C2Ph)(CO)₂(PPh₃)₂ are described.     

Binding energies and bonding nature of MX(CO)(PH3)2(C60) (M = Rh or Ir; X = H or Cl): Theoretical study

IrH(CO)(PH₃)₂(C₆₀), IrCl(CO)(PH₃)₂(C₆₀), and RhH(CO)(PH₃)₂(C₆₀) were theoretically investigated with DFT and MP2 to MP4(SDQ) methods.  Because the DFT method considerably underestimates the binding energy compared to the MP2 method, their binding energies were evaluated by the ONIOM(MP4(SDQ):UFF) method.  The binding energy decreases in the order IrH(CO)(PH₃)₂(C₆₀) (59.4) > RhH(CO)(PH₃)₂(C₆₀) (48.2) > Pt(PH₃)₂(C₆₀) (47.2) > IrCl(CO)(PH₃)₂(C₆₀) (43.0), where in parentheses are the binding energy (in kcal/mol) calculated with the ONIOM(MP4(SDQ):UFF) method and that of Pt(PH₃)₂(C₆₀) was calculated with the same method and the same basis sets in our previous work.  This decreasing order is interpreted in terms of the d_π orbital energy, the d orbital expansion, the presence of the empty d_σ orbital, and the distortion energy of the metal fragment induced by the complexation; for instance, the d_π orbital is at higher energy and more expands in IrH(CO)(PH₃)₂ than in the Rh analogue, which leads to the larger binding energy of IrH(CO)(PH₃)₂(C₆₀) than that of the Rh analogue. IrCl(CO)(PH₃)₂ is less favorable than IrH(CO)(PH₃)₂ because of the lower energy of d_π orbital.  Although the π-back donation is stronger in IrCl(CO)(PH₃)₂(C₆₀) than in RhH(CO)(PH₃)₂(C₆₀), the binding energy of IrCl(CO)(PH₃)₂(C₆₀) is smaller than that of RhH(CO)(PH₃)₂(C₆₀) due to the larger distortion energy of the IrCl-(CO)(PH₃)₂ moiety.  Although the d_π orbital of Pt(PH₃)₂ is at higher energy than that of IrH-(CO)(PH₃)₂, the binding energy of IrH(CO)(PH₃)₂(C₆₀) is larger than that of Pt(PH₃)₂(C₆₀) because the distortion energy is large and the d_σ orbital is doubly occupied in Pt(PH₃)₂(C₆₀).  It is also noted that these binding energies are much larger than those of the ethylene analogues like those of the Pt(0) complexes, which is reasonably interpreted in terms that the LUMO of C₆₀ is at much lower energy than those of ethylene.     

Übergangsmetall-substituierte acylphosphane und phosphaalkene: XI. Phosphaalkenyl-, disilylphosphido- und diacylphosphidokomplexe des dicarbonylpentamethylcyclopentadienylosmium. Zur kenntnis von [(η5-C5Me5)Os(CO)2]2

The reaction of Os₃(CO)₁₂ with C₅Me₅H in boiling decalin gives the complexes (η⁵-C₅Me₅)(CO)₂OsH and [(η⁵-C₅Me₅)(CO)₂Os]₂. Both compounds were converted into (η⁵-C₅Me₅)(CO)₂OsP(SiMe₃)₂ (III) via the intermediate form (η⁵-C₅-Me₅)(CO)₂OsBr. Complex III was treated with ArC(O)Cl (Ar = Ph, 2,4,6-Me₃C₆H₂) to give mixtures of the phosphaalkenyl complexes (η⁵-C₅Me₅)(CO)₂OsPC(OSiMe₃)(Ar) (IVa, b) and the diacylphosphido complexes (η⁵-C₅Me₅)(CO)₂-OsP[C(O)Ar]₂ (Va, b). Pivaloyl chloride underwent reaction with III to give complex Vc as the only product. The synthesis of the complexes IVa, b includes an E/Z isomerization process.     

Synthesis and structures of fulvene-bridged diruthenium complexes

Three diruthenium carbonyl complexes, namely (η ³:η ⁵-C₅H₄C(CH₂)₂)Ru₂(CO)₅ (1), (η ³:η ⁵-C₅H₄C(CHCH₂)(C₂H₅))Ru₂(CO)₅ (2), and (η ¹:η ⁵-C₅H₄C₅H₈)Ru₂(CO)₆ (3), were obtained from the reactions of C₅H₄C(Me)₂, C₅H₄C(Et)₂, and C₅H₄C(CH₂)₄, respectively, with Ru₃(CO)₁₂ in refluxing xylene. The complexes were characterized by elemental analysis, IR and ¹H NMR spectra. Single-crystal X-ray diffraction analysis for complexes 1 and 2 revealed that the fulvene ligands bridge two ruthenium atoms in η ³:η ⁵ fashion.     

Synthesis and structures of bridged biscyclopentadienyl diiron complexes

Three diiron carbonyl complexes, namely [(η ⁵-C₅H₄)(η ³-C(CH₂)₂)]Fe₂(CO)₅ (1), [(C₂H₅)₂C(η ⁵-C₅H₄)₂]Fe₂(μ-CO)₂(CO)₂ (2), and [(CH₂)₄C(η ⁵-C₅H₄)(η ⁵-C₅H₃)(C₅H₉)]Fe₂(μ-CO)₂(CO)₂ (3), have been synthesized by the reactions of C₅H₄C(Me)₂, C₅H₄C(Et)₂, and C₅H₄C(CH₂)₄, respectively, with Fe(CO)₅ in refluxing xylene. The complexes have been characterized by elemental analysis, IR, and ¹H NMR spectra. The molecular structures of the complexes have been determined by single-crystal X-ray diffraction. The structures of the complexes indicate that fulvenes can be bound to transition metal centers by diverse modes.     

Derivative des borols: VI. Dehydrierende komplexierung von borolenen mit carbonylmetallen: (borol)metall-komplexe von mangan,eisen und cobalt

The reaction of 2-borolenes and 3-borolenes C₄H₆BR (R = Ph, Me, C₆H₁₁, OMe) with Mn, Fe, and Co carbonyls leads to dehydrogenating complexation with formation of simple, i.e. C-unsubstituted (η⁵-borole)metal complexes. Thus, Mn₂(CO)₁₀ gives the triple-decked complexes (μ-η⁵-C₄H₄BR)[Mn(CO)₃]₂ (R = Ph, OMe). By irradiation of Fe(CO)₅ the half-sandwich complexes Fe(CO)₃ (η⁵-C₄H₄BR) (R = Ph, Me, C₆H₁₁, OMe) are formed, whereas Co₂(CO)₈ yields the dinuclear complexes (μ-CO)₂[Co(CO)(η⁵-C₄H₄BR)]₂ (Co-Co) (R = Ph, Me). A low-temperature X-ray structure determination of Fe(CO)₃(η⁵-C₄H₄BPh) is described in detail.