Cobalt metallocycles: IV. Ring opening of cobaltacyclopentadienes by addition of SiH,SH,NH and CH to the diene moiety

Cobaltacyclopentadiene complexes, (η⁵-C₅H₅)(PPh₃)($\text{CoCR}{}^1\text{CR}{}^2\text{CR}{}^2\text{C}$R¹) (R¹, R² =; Ph, Me, CO₂Me), reacted with RH (RH: triethylsilane, thiocresol, dimethyl- and ethylene-thiourea, pyrrole, thiophene) to give diene complexes, (η⁵-C₅H₅)(η⁴-HCR¹CR²CR²CR¹R)Co, or uncomplexed, highly substituted butadiene derivatives, HCR¹CR²CR²CR¹R. The reaction with thiourea proceeded catalytically in the presence of excess of diphenylacetylene although turn-over of the catalyst was small.     

Structure,spectral properties and interconversions of bis-niobocenes and their dianions. The crystal and molecular structure of [(η5-C5H4SiMe2OSiMe2-η5 : η1-C5H3)2Nb2H2] [Na(OEt2)2]2

Electron-acceptor properties of bis-niobocenes (η⁵-C₅H₄Y)(H)$\text{Nb(η}{}^5\text{: η}{}^1\text{-C}{}_5\text{H}{}_3\text{X)}{}_2\text{N}$b(H)(η⁵-C₅H₄Y) with X  Y  H and XY  SiMe₂OSiMe₂have been investigated. Bis-niobocenes are shown to readily add two electrons forming stable salts of the corresponding dianions [(η⁵-C₅H₄Y)(H)Nb(η⁵ : η¹- C₅H₃X)₂Nb(H)(η⁵-C₅H₄Y)]^2-. The surplus electrons can be removed to give quantitative regeneration of initial neutral bis-niobocenes. The crystal and molecular structure of the title compound has been determined; R  0.044, interatomic distance are Nb…Nb 3.93, NbH 1.62, average NbC(π) 2.36, NbC(σ) 2.31 Å, other distances correspond to the usually observed values. Unlike the neutral bis-niobocenes, there is no direct metalmetal bond in the dianionic structures. This conclusion is supported by electronic spectra of neutral and dianionic species.     

Cyclopentadienyl-ruthenium and -osmium chemistry: XXIV. Some complexes containing the olefinic tertiary phosphine 2-CH2CHC6H4PPh2 (sp): X-ray structures of one isomer of OsBr(sp)(η-C5H5), and of Ru(η3-S2CCHMeC6H4PPh2-2)(η-C5H5), containing an η3-dithiocarboxylato group

Reactions between MX(PPh₃)₂(η-C₅H₅) (M = Ru, X = Cl; M = Os, X = Br) and 2-CH₂CHC₆H₄PPh₂ afford $\text{MX(η}{}^2\text{-CH}{}_2\text{CHC}{}_6\text{H}{}_4\text{P}$Ph₂)(η-C₅H₅); the Os complex is obtained in two isomeric forms. The X-ray structure of the major isomer shows the CC double bond (OsC, 2.214, 2.195 Å; CC, 1.57 Å) is almost coplanar with the OsBr vector, with the terminal C cis to Br; the minor isomer is assumed to have the alternative, more sterically congested conformation, with the β-C cis to Br. The chlororuthenium complex reacts with NaOMe/MeOH to give the corresponding hydrido complex, which also exists as two isomers in solution; reaction of this complex with CS₂ gives the expected dithio acid derivative $\text{Ru(S}{}_2\text{CCHMeC}{}_6\text{H}{}_4\text{P}$Ph₂)(η-C₅H₅), together with small amounts of a complex assumed to be $\text{Ru[S}{}_2\text{C(CH}{}_2\text{)}{}_2\text{C}{}_6\text{H}{}_4\text{P}$Ph₂](η-C₅H₅). The X-ray structure of the major product reveals an unusual η³-S₂C mode of coordination of the dithio acid fragment (RuS, 2.418, 2.426(1) Å; RuC 2.175(4) Å). Crystals of OsBr(η²-CH₂CHC₆H₄P)Ph₂)( η-C₅H₅) are monoclinic, space group P2₁/n, with a 12.696(2), b 21.719(6), c 15.929(3) Å, β 79.77(2)°, Z = 8; 2867 data (I > 2.5σ(I)) were refined to R = 0.040, R_w = 0.044. Crystals of $\text{Ru(η}{}^3\text{-S}{}_2\text{CCHMeC}{}_6\text{H}{}_4\text{P}$Ph₂)(η-C₅H₅) are orthorhombic, space group Pbca, with a 8.921(2), b 15.982(9), c 32.216(5) Å, Z = 8; 1685 data (I > 2.5σ(I)) were refined to R = 0.027, R_w = 0.030.     

Synthesen im system {carbonylmetallat/ketenimin/säure}: XXX. Neue ferra- und rhenaazetidine

The metal carbonyl anions [Fe(η-C₅H₅(CO)₂]^? and [Re(CO)₅] undergo regio- and site-specific [2 + 2]-cycloadditions with the ketenimines Ph₂CCNR (R = Me, Ph) to give the (isolable) anionic complexes [L_n$\text{M{C(CPh}{}_2\text{)N(R)C}$(O)}]^? (L_nM = Fe(η-C₅H₅)CO, Re(CO)₄) which have been alkylated and acylated at the exocyclic oxygen atom of the carbonyl function. The result is stable neutral complexes having a metallaazetidine structure which is composed of an α-metallated enamine and an N,O carbene part. IR, ¹H, and ¹³C NMR data are presented.     

Cyclopentadienyl-ruthenium and -osmium chemistry: XXVIII. Reactions and isomerisation of 1,2-bis(methoxycarbonyl)ethenyl complexes: X-ray structures of Ru{Z)-C(CO2Me)CH(CO2Me)} -(CO)(PPh3)(η-C5H5) · 0.5EtOH,Ru{(E)-C(CO2Me)CH(CO2Me)}(dppe)(η-C5H5) and Ru{C(CO2Me)C(CO2Me)C(CO2Me)CH(CO2Me)} - (PPh3)(η-C5H5)

A reinvestigation of the reaction between C₂(CO₂Me)₂ and RuH(PPh₃)₂(η-C₅H₅) and some related complexes is reported. Initial cis addition is followed by conversion into the trans isomer. In the case of the bis-(PPh₃) complex, isomerisation is followed by chelation of the ester CO group with concomitant displacement of one PPh₃ligand. The resulting chelate complex reacts with CO or CNBu^t to give the (Z)-RuC(CO₂Me)CH(CO₂Me) complexes; the (E)-isomer of the carbonyl complex is obtained by addition of C₂(CO₂Me)₂to RuH(CO)(PPh₃)(η-C₅H₅). The ^1Hand ¹³C NMR spectra are not a reliable guide to assignment of the stereochemistry of the vinyl group. Other products isolated from the initial reaction are the bis-insertion product $\text{Ru{C(CO}{}_2\text{Me)C(CO}{}_2\text{Me)C(CO}{}_2\text{Me)}$CH(CO₂Me)} -(PPh₃)(η-C₅H₅) and the 1/2 PPh₃/C₂(CO₂Me)₂ adduct. The molecular structures of Ru{(Z)-C(CO₂Me)CH(CO₂Me)}(CO)(PPh₃(η-C₅H₅) · 0.5EtOH, Ru{(E)-C(C₂Me)CH(CO₂Me)}(dppe)(η-C₅H₅) and $\text{Ru{C(CO}{}_2\text{Me)C(CO}{}_2\text{Me)C(CO}{}_2\text{-Me)}$CH(CO₂Me)}(PPh₃)(η-C₅H₅) have been determined. The cis isomer is monoclinic, space group P2₁,with a 9.328(8), b 17.385(10), c 10.356(7) Å, β 101.78(3)° and Z = 2; 2107 data with I ≥ 2.5σ(I) were refined to R = 0.076 R_w = 0.085. The trans isomer is triclinic, space group P$\text{1}$, with a 10.404(7) b 11.221(6), c 13.230(9) Å, α 92.67(5), β 110.56(5), γ 106.21(5)° and Z = 2; 2520 data with I ≥ 2.5σ(I) were refined to R = 0.055 R_w = 0.068. The butadienyl complex is monoclinic, space group P2₁/a, with a 19.655(8), b 8.674(4), c 21.060(5) Å, β 116.22(3)° and Z = 4; 2724 data with I ≥ 2.5σ(I) were refined to R = 0.042, R_w = 0.047.     

Cobalt metallocycles: XIII. Preparation and x-ray crystallography of cobaltacyclopentadiene and dinuclear cobalt complexes

(η-Cyclopentadienyl)(triphenylphosphine)cobaltacyclopentadienes having an electron withdrawing substituent on the cyclopentadienyl ring, (η-C₅H₄R)(PPh₃)($\text{CoCHCHC}$H) (1b: R = COOMe; 1c: R = COMe), were prepared in reasonable yields by treatment of a solution of (η-C₅H₄R)(PPh₃)₂Co with acetylene. A non-substituted cyclopentadienyl analog (1a: R = H) was also isolated in low yield according to a similar procedure. Novel dinuclear complexes were also formed as by-products and the structure of (η-C₅H₄R)Co(PPh₂$\text{C}{}_6\text{H}{}_4\text{)(μ-C}$Me)Co(η-C₅H₄R) (2b: R = COOMe), having a μ₂,η³-benzyl moiety, was determined by an X-ray crystallographic analysis. The X-ray analyses of 1a and 1b were also carried out. Crystals of 1a are monoclinic, space group Pa, a 8.529(3), b 16.010(6), c 8.028(4) Å, β 100.31(3)°, Z = 2; crystals of 1b are monoclinic, space group P2₁/a, a 8.327(2), b 36.468(7), c 8.021(1) Å, β 98.75(2)°, Z = 4; and crystals of 2b are monoclinic, space group P2₁/c, a 10.681(2), b 30.722(7), c 8.912(1) Å, β 93.55(1)°, Z = 4. They have been refined to R = 0.034, 0.047 and 0.050, respectively.     

Darstellung und eigenschaften von und reaktionen mit metallhaltigen heterocyclen XX. Darstellung,eigenschaften und kristallstruktur von λ4-thia-λ5-phospha-h2-metallabicyclo[2.2.1]heptadienen und ihre verwendung zur synthese von metallorganischen und organischen verbindungen

The novel λ⁴-thia-λ⁵-phospha-h²-manganabicyclo[2.2.1]heptadienes (OC)₃Mn[$\text{CR}{}^2\text{CR}{}^2\text{CR}{}^2\text{CR}{}^2\text{PR}{}^1{}_2\text{S}$] (R¹ = CH₃, C₆H₅; R² = CO₂CH₃, CO₂C₂H₅, CO₂C₆H₁₁) are formed by action of the activated alkynes R²C  CR² on the heterocycles [(OC)₄MnPR¹₂S]₂ via the isolable, five-membered heterometallacyclopentadienes (OC)₄$\text{MnSPR}{}^1{}_2\text{C(R}{}^2\text{)C}$(R²). The compound with R¹ = CH₃ and R² = CO₂CH₃ crystallizes in the triclinic space group P$\text{1}$ with Z = 2 and separates quantitatively the thiophene derivative $\text{CR}{}^2\text{CR}{}^2\text{CR}{}^2\text{CR}{}^2\text{S}$ under CO pressure or by reaction with (NH₄)₂Ce(NO₃)₆. The use of various acetylenes and of acetylenes with different alkyl groups yields the unsymmetric substituted manganabicycloheptadienes (OC)₃Mn[$\text{CR}{}^4\text{CR}{}^3\text{CR}{}^2\text{CR}{}^2\text{P(CH}{}_3\text{)}{}_2\text{S}$] (R² = CO₂CH₃, R³ = R⁴ = CO₂C₂H₅; R² = R⁴ = CO₂CH₃, R³ = H). With propionic acid methylester the alkyne insertion proceeds regiospecifically. With Raney nickel selective S elimination under ring contraction and formation of the λ⁴-phospha-h²-manganabicyclo[2.1.1]hexenes (OC)₃Mn[$\text{CR}{}^2\text{CR}{}^3\text{CR}{}^2\text{CR}{}^2\text{P}$R¹₂] (R¹ = CH₃: R² = R³ = CO₂CH₃, CO₂C₂H₅; R² = CO₂CH₃, R³ = H; R¹ = C₆H₅: R² = R³ = CO₂C₂H₅) occurs. (OC)₃Mn[$\text{CR}{}^2\text{CR}{}^3\text{CR}{}^2\text{CR}{}^2\text{P}$(CH₃)₂] (R² = R³ = CO₂CH₃) crystallizes in the monoclinic space group P2₁/m with Z = 2. The IR and NMR spectra of the heterocycles are discussed in detail.     

Synthesis of monohydridohexamethylbenzeneruthenium(II) complexes containing group V donor ligands. Isomerism arising from cyclometallation of a tertiary phosphine at aliphatic and aromatic carbon atoms

The η-hexamethylbenzenehydridoruthenium(II) complexes RuHCl(η-C₆Me₆)L (L = PPh₃ (11), AsPh₃ (12), P(C₆H₄-p-F)₃ (14), P(C₆H₄-p-Me)₃ (15), P(C₆H₄-p-OMe)₃ (16), P-t-BuPh₂ (17), P-i-PrPh₂ (18), P-i-Pr₃ (19), PCy₃ (20) and P-t-BuMe₂ (21)) have been made by heating [RuCl₂(η-C₆Me₆)]₂, the ligand and sodium carbonate in propan-2-ol. The triarylphosphine complexes 11, 14 and 15 react with methyllithium to give aryl ortho-metallated hydridoruthenium(II) complexes such as $\text{RuH(}\text{o}\text{-C}{}_6\text{H}{}_4\text{P}$Ph₂)(η-C₆Me₆) (22) and 19 similarly gives the isopropyl cyclometallated complex $\text{RuH(CH}{}_2\text{CHMeP}$-i-Pr₂(η-C₆Me₆) (29) as a mixture of diastereomers. Reaction of 17 with methyllithium gives initially the t-butyl cyclometallated complex $\text{RuH(CH}{}_2\text{CMe}{}_2\text{P}$Ph₂)(η-C₆Me₆) (25) which isomerizes by a first order process (k$\text{0}\text{?}$.2 h^?1 in C₆D₆ or THF-d₈ at 50°C) to the aryl ortho-metallated complex $\text{RuH(}\text{o}\text{-C}{}_6\text{H}{}_4\text{P}$-t-BuPh)(η-C₆Me₆) (26). The similarly generated isopropyl cyclometallated complex $\text{RuH(CH}{}_2\text{CHMeP}$Ph₂)(η-C₆Me₆) (27) has not been isolated in a pure state owing to rapid isomerization to $\text{RuH(}\text{o}\text{-C}{}_6\text{H}{}_4\text{P}$-i-PrPh)(η-C₆Me₆) (28); both 27 and 28 exist as a pair of diastereomers. The formation of the cyclometallated complexes and the isomerizations are thought to involve intermediate 16-electron ruthenium(O) complexes Ru(η-C₆Me₆)L.     

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.     

Synthesis of homoleptic tris(organo-chelate)iridium(III) complexes by spontaneous ortho-metallation of electronrich olefin-derived N,N′-diarylcarbene ligands and the X-ray structures of fac-[Ir{CN(C6H4Me-p) (CH2)2NC6H3Me-p}3] and mer-Ir{CN(C6H4Me-p)(CH2)2NC6H3Me-p}2 {CN(C6H4Me-p)(CH2)2NC6H4Me-p}Cl (a product of HCl cleavage)

Treatment of [{Ir(COD)(μ-Cl)}₂] with excess of the electron-rich olefin [$\text{CN(Ar)(CH}{}_2\text{)}{}_2\text{N}$Ar]₂ (abbreviated as (L^Ar)₂, Ar = C₆H₄Me-p or C₆H₄OMe-p) affords the ortho-metallated tricycle [$\text{Ir(L}{}^{\mathrm{A}}\text{r}$)₃], which for Ar = C₆H₄Me-p (Ia) with HCL yields [$\text{Ir(L}{}^{\mathrm{A}}\text{r}$)₂(L^Ar)]Cl (IV); X-ray data show that in IV there is an unexpectedly close Ir?C(o-aryl) contact (2;52(1) Å) involving the “free” L^Ar which compares with an IrC(o-aryl) distance of 2.09(3) Å in Ia or 2.07(3) Å in the ortho-metallated L^Ar ligand of complex IV.     

Syntheses of σ-cyclobut-1-en-3-onyl complexes by cycloaddition of ketenes to some transition metal alkynyl complexes

Reactions of ketenes (R¹R²CCO) with (η⁵-C₅H₅)Ni(PPh₃)CCR (I) and (η⁵-C₅H₅)Fe(CO)(L)CCR (III, L = CO and PPh₃) give σ-cyclobut-1-en-3-onyl complexes, {(η⁵-C₅H₅)Ni(PPh₃)$\text{CC(R)COC}$}R¹R² (VI) and (η⁵-C₅H₅)Fe(CO)(L)$\text{CC(R)COC}$R¹R² (IX)}, (2 + 2) cycloaddition products, in good yields. The σ-cyclobutenonyl complexes also can be prepared by the reaction of I and III with acyl chlorides in the presence of triethylamine.     

Übergangsmetall-Fulven-Komplexe: XXXII. Heteronukleare Zweikernkomplexe des Azulens

The molecular structure of the dinuclear complex [(η⁶-benzene)M$\text{o(μ-η}{}^6\text{: η}{}^4\text{-azulene)C}$r(CO)₃ was determined by an X-ray diffraction study. The reaction of [(η⁶-azulene)(η⁶-benzene)Mo] with [RhCI(CO)₂]₂ gives the salt [η⁶-benzene)M$\text{o(μ-η}{}^6\text{: η}{}^4\text{-azulene)R}$h(CO)₂]₊[RhCl₂(CO)₂]^?, the structure of which was also characterized by X-ray crystallography. The cation of this salt can also be synthesized from [(η⁶-azulene)(η⁶-benzene)Mo] and [Rh(CO)₂]⁺. The fluxionality of the cation was studied by temperature-dependent ¹H-NMR measurements. The complex [(η⁶-azulene)(η⁶-benzene)Mo] reacts with Fe₂(CO)₉ to give the dinuclear complex [(η⁶-benzene)M$\text{o(μ-η}{}^5\text{:}{}_3\text{-azulene)F}$e(CO)₃], as confirmed by X-ray diffraction.     

Inorganic Chemistry: Towards the 21st Century. : ACS Symposium Series 211 (Ed. M.H. Chisholm), American Chemical Society,Washington, D.C., 1983, ix + 566 pages, $67.95 ($55.95, USA and Canada)

The preparation of the first mixed metal cyclometallated compounds [ClP$\text{d(}\text{p}\text{-RC}{}_6\text{H}{}_3\text{CHNNCH(}\text{p}\text{-RC}{}_6\text{H}{}_3\text{))P}$tCl]_n (R = H, Cl) are reported; they were made from monocyclopalladated [(AcO)P$\text{d(}\text{p}\text{-RC}{}_6\text{H}{}_3\text{CHNN}$CH(p-RC₆H₄)]₂ and PtCl₄^2?.     

Cyclometallation reactions of N-(benzylidene)benzylamines with palladium compounds

The cyclometallation of p-RC₆H₄CHNCH₂C₆H₂, (R = H, Cl, NO₂) by PdX₂ (X = Cl, AcO) has been studied.In every case the cyclometallation occurs with formation of a five-membered ring containing the methine group. The structure of these compounds [$\text{PdX(}\text{p}\text{-RC}{}_6\text{H}{}_3\text{CHN}$CH₂C₆H₅)]₂, derived from ¹H NMR spectra, are different from those reported previously. Reaction of these compounds with PEt₃ gives the compounds [PdX(p-RC₆H₃CHNCH₂C₆H₅)(PEt₃)₂] but with an excess of PPh₃ only the complexes [$\text{PdX(}\text{p}\text{-RC}{}_6\text{H}{}_3\text{CHN}$CH₂C₆H₅)(PPh₃)] are formed.     

Darstellung ylidischer metallacyclopropankomplexe durch ringverkleinerung metallacyclischer vinylketonkomplexe. Molekülstruktur von C5H5W(CO)2[(PMe3)HC-CH(COMe)]

The addition of trimethylphosphane to five-membered metallacyclic vinylketone complexes of the type Ar$\text{M(CO)}{}_2\text{(HCCHCO}$R) (I) (Ar = η⁵-aromatic ring system: C₅H₅, C₅H₄Me, C₅Me₅; R = Me, Et, n-Bu; M = Mo, W) in pentane solution results in the formation of the ylidic metallacyclopropane complexes Ar$\text{M(CO)}{}_2\text{[(PMe}{}_3\text{)-HCC}$H(COR)] (II). In these 1:1 adducts the three-membered ring is stabilized by an electron-donating phosphonium and an electron-attracting acyl substituent. The negative charge in the ylidic complexes II is localized on the central metal providing it with Lewis base properties. An extraordinary high electron density can be observed on the metal of the derivative C₅H₅$\text{W(CO)(PMe}{}_3\text{)[(PMe}{}_3\text{)HCC}$H-(COMe)] (III) which is formed by a 1:2 addition of C₅H₅W(CO)(C₂H₂)-(COMe) and PMe₃. The metallacyclopropane complexes II and III are characterized by IR, ¹H NMR, ¹³C NMR, ³¹P NMR and mass spectroscopy. For C₅H₅$\text{W(CO)}{}_2\text{[(PMe}{}_3\text{)HCC}$H(COMe)], the results of an X-ray structure determination are presented.     

Darstellung und eigenschaften von und reaktionen mit metallhaltigen heterocyclen XXII. Synthese, eigenschaften und kristallstruktur des sechsgliedrigen heterocyclus [(h-C5H5)NiSP(CH3)2]2 und dessen verhalten gegenüber alkinen

The heterocycle [(h⁵-C₅H₅)NiSP(CH₃)₂]₂ is obtained by treatment of (h⁵-C₅H₅)₂Ni with (CH₃)₂HPS in toluene and crystallizes monoclinic in the space group P2₁/c with Z = 2. The highly reactive three-membered ring (h⁵-C₅H₅)$\text{NiSP}$(CH₃)₂ which is a dissociation product of [(h⁵-C₅H₅)NiSP(CH₃)₂]₂, can be trapped with bis(methoxycarbonyl)acetylene to give the PS containing nickelacyclopentadiene (h⁵-C₅H₅)$\text{NiSP(CH}{}_3\text{)}{}_2\text{CRC}$R (R  CO₂CH₃).     

Thermally induced ortho-metalation of dicarbomethoxyacetylenebis(triphenylphosphine)platinum

Heating a toluene solution of dicarhomethoxyacetylenebis(triphenylphosphine)platinum(0) at 130°C gives the ortho-metalated complex (Ph₃P)(Ph₂$\text{PC}{}_6\text{H}{}_4\text{)P}$t-trans-(COOMe)CCHCOOMe.     

Four-membered chelate aminoalkenyl complexes of platinum(II). Synthesis,carbonylation and oxidation to aminoacidato complexes

Amination of Pt^II-allene complexes of the type cis[PtCl₂(Me₂CCCHR)(PPh₃)] gives the new four-membered C, N chelate aminoalkenyl complexes [$\text{PtC(CMe}{}_2\text{)CHRN}$Me₂(PPh₃)Cl]. These undergo ready insertion of carbon monoxide into the CPt σ-bond; the resulting acyl complexes are oxidized by hydrogen peroxide to aminoacidato complexes, and the free unsaturated β-aminoacids can be recovered in good yield by ligand displacement.