Reactions and properties of some trimethyleneplatinum(IV) complexes: V. The kinetics and mechanism of formation from arylcyclopropanes

The kinetics of the reaction of arylcyclopropanes (4-XC₆H₄C₃H₅, X = H, Me, EtO) with either [Pt₂Cl₂(μ-Cl)₂(C₂H₄)₂] or [{$\text{PtCl}{}_2\text{(CH}{}_2\text{CH}{}_2\text{C}$H₂)} in tetrahydrofuran to give in each case [{$\text{PtCl}{}_2\text{(CHArCH}{}_2\text{C}$H₂)}₄] and ethylene or cyclopropane, respectively, have been studied. The reactions are essentially first order in both arylcyclopropane and platinum complexes. The order of reactivity follows the series X = EtO > > Me > H, and [Pt₂Cl₂(μ-Cl)₂(C₂H₄)₂]> [{$\text{PtCl}{}_2\text{(CH}{}_2\text{CH}{}_2\text{C}$H₂)}4] and the rate is accelerated in polar solvents. Mechanisms in which the arylcyclopropane first coordinates to platinum and then undergoes ring opening reactions are proposed.     

Oxidation of coordinated olefins: the reactions of Cl2 with trichloro(ehtylene)platinate(II)

The oxidation of [PtCl₃(C₂H₄)]- by Cl₂ in aqueous solution, to yield CH₂ClCH₂OH and [PtCl₄]^2-, has been shown to proceed through the following sequence of steps: [PtCl₃(C₂H₄)] Cl₂Cl [PtCl₅(CH₂CH₂Cl)]^2-$\text{H}{}_2\text{O}\text{(HCl)}$ [PtCl₅(CH₂CH₂OH)]^2- → [PtCl₄^2- + CH₂ClCH₂OHEach of the steps and intermediates in this mechanistic sequence has been identified and characterized.     

Isomerisation in the chemistry of platinacyclobutane complexes

The platinacyclobutane complexes PtCl₂L₂(C₃H₅Me)], L  pyridine, CD₃CN, or tetrahydrofuran, exist as mixtures of isomers containing P$\text{tCH}{}_2\text{CHMeC}$H₂ or P$\text{tCHMeCH}{}_2\text{CH}{}_2$ groups in rapid equilibrium. Decomposition occurs in some cases to give [PtCl₂L(CH₃CH₂CHCH₂)]. Stereospecific skeletal isomerisation also occurs in metallocyclobutanes containing the groups P$\text{tCHRCHRC}$H₂  P$\text{tCHRCH}{}_2\text{C}$HR, when R  aryl further decomposition gives ν-allylplatinum complexes.     

The photodecomposition of platinacycloalkanes in solution: II. 1,4-butanediylplatinum(II) and (IV) compounds

The products of the photolysis of a number of platinacyclopentanes in solution at 25°C under a variety of conditions have been determined. With [I₂P$\text{tCH}{}_2\text{CH}{}_2\text{CH}{}_2\text{C}$H₂(L₂)] (L = PMe₂Ph, PPh₃) in CH₂Cl₂, CH₂Br₂ and (CH₃)₂SO the hydrocarbon products are exclusively ethylene and but-1-ene. Formation of the latter through a 1,3-hydrogen shift is preceded by phosphine ligand dissociation. The photolysis of [ICH₃P$\text{tCH}{}_2\text{CH}{}_2\text{C}$H₂(L₂)] gave methane, ethylene, but-1-ene and n-pentane together with a little n-butane, the methane being formed from internal hydrogen abstraction by the CH₃ group in the excited reactant molecule. Photodecomposition of the platinum(II) compounds [P$\text{tCH}{}_2\text{CH}{}_2\text{CH}{}_2\text{C}$H₂(L₂)] (L = (PMe₂Ph)₂, (PPh₃)₂, Ph₂PCH₂CH₂PPh₂) gave ethylene, but-1-ene, pent-1-ene (with the halogenated solvents) and with some systems appreciable yields of n-butane, the latter being the results of internal abstraction of two hydrogen atoms by the C₄H₈ moiety. The formation of pentene is probably preceeded by the addition of CH₂Cl₂ or CH₂Br₂ to the excited reactant molecule. Addition of diphenylphosphine promotes the production of n-butane.     

Transition metalcarbon bonds: LV. Cyclometallation and other reactions of PBut2Bui and PPh2Bui with platinum(II) and palladium(II)

The new phosphine, PBu^t₂Buⁱ (L), was prepared from Bu^t₂PCl and LiBuⁱ. PPh₂Buⁱ (L′) was prepared from Ph₂PCl and LiBuⁱ. Treatment of [PtCl₂(NCBu^t)₂] with L′ gives [PtCl₂L′₂] which does not cyclometallate even on prolonged boiling in 2-methoxyethanol. In contrast, [PtCl₂(NCBu^t)₂] reacts with PBu^t₂Buⁱ in boiling 2-methoxyethanol to give the cyclometallated complex [$\text{Pt}{}_2\text{Cl}{}_2\text{(PBu}{}^{\mathrm{t}}{}_2\text{CH}{}_2\text{-CHMeCH}$₂)₂] (II, X = Cl). The corresponding bromide, iodide and acetylacetonate were prepared. With PPh₃ II (X = Cl) gives [$\text{PtCl(PBu}{}^{\mathrm{t}}{}_2\text{CH}{}_2\text{CHMeCH}$₂)(PPh₃)] which with NaBH₄ gives [$\text{PtH(PBu}{}^{\mathrm{t}}{}_2\text{CH}{}_2\text{CHMeC}$H₂)(PPh₃)]. Na₂PdCl₄ with L (2 mol equivalents) gave trans-[PdCl₂L₂], which was converted into trans-[Pd(NCS)₂-L₂] by metathesis with KSCN. Treatment of Na₂PdCl₄ with L (1 mol equivalent) gave [Pd₂Cl₄L₂], which on heating in 2-methoxyethanol gave [$\text{Pd}{}_2\text{Cl}{}_2\text{(PBu}{}^{\mathrm{t}}{}_2\text{CH}{}_2\text{-CHMeCH}$₂)₂], as a mixture of syn- and anti-isomers. The complexes trans-[PdCl₂-L′₂] and [Pd₂Cl₄L′₂] were also prepared. ¹H- and ³¹P NMR data are given.     

Reactions of hydridosilacyclobutanes with low-valent complexes of iron or platinum

Unstable transition metal compounds formed from hydridosilacyclobutanes are described: 1-methyl-1-silacyclobutane reacts with nonacarbonyldiiron to give the complexes [Fe(CO)₄(H){$\text{Si(Me)CH}{}_2\text{CH}{}_2\text{C}$H₂}] and [$\text{Fe{CH}{}_2\text{CH}{}_2\text{CH}{}_2\text{Si}$(H)Me}(CO)₄], and with bis(triphenylphosphine)(ethylene)platinum(0) to give [Pt(H)(PPh₃)₂{$\text{Si(Me)CH}{}_2\text{CH}{}_2\text{C}$H₂}].     

The photolysis of platinacycloalkanes in solution

The photolysis of [I₂$\text{PtCH}{}_2\text{CH}{}_2\text{CH}{}_2\text{C}$H₂ (PMe₂ Ph)₂] gives ethylene and but-1-ene as volatile products, the latter probably being formed via a five-coordinate platinum intermediate. However, the formation of propene from the photolysis of [Cl₂$\text{PtCH}{}_2\text{CH}{}_2\text{C}$H₂ (1,10-phenanthroline) appears to involve a direct transfer of a hydrogen atom between neighbouring CH₂ groups in the ring. Other gaseous products, e.g. cyclopropane, ethylene, may be formed via a platinum ion radical.     

On the possibility of a carbenium ion structure for the complexes [Os3H3(CO)9CCR2]+. Further application of the 187Os nucleus

In the ¹H NMR spectrum of the complex [Os₃H₃(CO)₉C$\text{C(CH}{}_2\text{C}$H₂]⁺ at 30°C, under conditions of rapid exchange, the single hydride resonance has two sets of satellites of equal intensity (separated by 32.0 and 28.8 Hz) caused by ¹⁸⁷Os¹H spin—spin coupling. The spectral data rule out the upright carbenium ion structure for the complex, and are consistent with the fluxional process involving hydrocarbon ligand rotation about the C$\text{C(CH}{}_2\text{)}{}_2\text{C}$H₂ axis in a tilted structure, with concomitant rotation of the Os₃H₃(CO)₉ moiety.     

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.     

A novel synthesis of carbene complexes of manganese and molybdenum containing the trichlorogermyl group

A number of carbene complexes of formulas Cl₃GeMn(CO)₄C(OR′)R and C₅H₅Mo(CO)₂(GeCl₃)C(OR′)CH₃ (R = CH₃, C₆H₅; R′ = CH₃, C₂H₅) have been prepared by the reaction of [N(C₂H₅)₄]GeCl₃ with CH₃Mn(CO)₅, C₆H₅Mn(CO)₅, or C₅H₅Mo(CO)₃CH₃ followed by alkylation of the resulting trichlorogermylacylcarbonylmetallate ion. The compound C₅H₅Mo(CO)₂(GeCl₃)$\text{COCH}{}_2\text{CH}{}_2\text{C}$H₂ has been prepared directly by the reaction of [N(C₂H₅)₄]GeCl₃ with C₅H₅Mo(CO)₃(CH₂)₃Br.     

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.     

Cyclometallation reactions XII. On the effect of various leaving groups on internal metallation reactions with alkylmanganese complexes

The interaction of azobenzene and MnR(CO)₅ (R  Me, Et, CH₂Ph, CH₂-C₆Me₅, COCF₃, COCH₂C₆F₅, COCH₂OPh, Ph or C₆F₅) affords M$\text{n(C}{}_6\text{H}{}_4\text{NN}$Ph)-(CO)₄, together with a binuclear complex Mn₂(CO)₆(C₁₂H₁₀N₂) in some cases. The metallation reaction is shown to proceed most readily with Mn-(CH₂Ph)(CO)₅; with this reagent, the metallated complexes M$\text{n(C}{}_6\text{H}{}_4\text{CH}{}_2\text{P}$Me₂)-(CO)₃[PMe₂(CH₂Ph)] (two isomers) and M$\text{n(C}{}_6\text{H}{}_4\text{CH}{}_2\text{A}$sMe₂(CO)₄ have been obtained on treatment with EMe₂(CH₂Ph) (E  P and As, respectively).     

Transition metal complexes of hexaphenylcarbodiphosphorane

The displacement of tetrahydrofuran (THF) from W(CO)₅(THF) with hexaphenylcarbodiphosphorane yields a compound with a carbon-metal bond (CO)₅W C[P(C₆H₅)₃]₂. The in situ photolysis of tungsten hexacarbonyl and hexaphenylcarbodiphosphorane, however, yields a product (CO)₅W^?CC ⁺P(C₆H₅)₃. Ethylenebis(triphenylphosphine)platinum and hexaphenylcarbodiphosphorane in benzene yield a platinum containing heterocycle [(C₆H₅)₃P]₂$\text{PtC[ P(C}{}_6\text{H}{}_5\text{)}{}_3\text{]P}$-(C₆H₅)₃.     

Darstellung und eigenschaften von und reaktionen mit metallhaltigen heterocyclen: XXV. Synthese und eigenschaften neuer platina- und rhodacycloalkane durch substitution und oxidative addition einer CCl-bindung

The platinacyclopentane derivative [Cl(CH₂)₃R₂P](Cl)$\text{PtPR}{}_2\text{CH}{}_2\text{CH}{}_2\text{CH}{}_2$ is formed by action of Cl(CH₂)₃PR₂ on Pt(COD)₂ in n-hexane via the not isolable Pt[PR₂(CH₂)₃Cl]₂ (R  C₆H₁₁) by oxidative addition of a CCl bond to platinum. [μ-CIRh(CO)₂]₂ reacts in benzene with Cl(CH₂)₃PR₂ under partially CO substitution to give the stable intermediate Cl(OC)Rh[PR₂(CH₂)₃Cl]₂. In boiling toluene oxidative addition of a CCl bond to rhodium occurs under formation of the phospharhodacyclopentane [CI(CH₂)₃R₂P] Cl₂(OC)-$\text{RhPR}{}_2\text{CH}{}_2\text{CH}{}_2\text{CH}{}_2$ (R  C₆H₅). The ³¹P{¹H}-NMR spectra of the rhodium compound is characterized by an ABX system, that of the platinum by superposition of an ABX pattern with an AB spectrum.     

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.     

Metallorganische verbindungen des iridiums und rhodiums: XXVI. CH-metallierung und hydridbildung im system Ir2Cl2(C8H14)4/PR3(PR3 = P(CH2CMe3)3, t-BuP(CH2CMe3)2, t-Bu2PCH2CMe3; i-Pr3P

Treatment of Ir₂Cl₂(C₈H₁₄)₄ with the phosphines t-Bu_3?nP(CH₂CMe₃)_n (n = 3,2,1) in hot toluene followed by crystallization of the products from C₇H₈/ EtOH mixtures gave the cyclometallated hydrides (C₈H₁₄)₂Ir-μ-Cl₂$\text{IrH[CH}{}_2\text{CMe}{}_2\text{CH}{}_2\text{P}$(CH₂CMe₃)₂][P(CH₂ (I) [t-BuP(CH₂CMe₃)₂]₂H₂Ir-μ-Cl₂$\text{IrH[CH}{}_2\text{CMe}{}_2\text{CH}{}_2\text{P}$Bu^t(CH₂CMe₃)][t-BuP(CH₂CMe₃)₂] (II), and [(t-Bu₂$\text{PCH}{}_2\text{CMe}{}_2\text{CH}{}_2\text{)HI}$rCl]₂ (III). The dihydrides IrH₂Cl[t-BuP(CH₂CMe₃)₂]₂ (IIa) and IrH₂Cl(t-Bu₂PCH₂CMe₃)₂ (IIIa) were also isolated; these species were, however, more conveniently obtained by bubbling hydrogen through the solution of Ir₂Cl₂ (C₈H₁₄)₄ and the respective phosphine in toluene. i-Pr₃ reacted with the olefiniridium(I) precursor in C₇H₈/EtOH to yield the carbonyl complexes (i-Pr₃P)₂H₂Ir-μ-Cl₂Ir(CO)(PPrⁱ₃)₂ (IV) and IrCl(CO)(PPⁱ₃)₂ (IVa), no cyclometallated product being detected. The stereochemistries of the complexes were deduced from IR, ¹H, ³¹P, and ¹³C NMR data. The crystal structures of IIIa and IVa were also determined.     

Some bridged η:η-dicyclopentadienyltitanium pyrazolone complexes: Syntheses and structural elucidation

Complexes of the types (C₅H₅)₂TiClL, (C₅H₅)TiClL₂ and [(C₅H₄)TiL₂]₂ (L is a monofunctional bidentate ligand) have been made by reactions of titanocene dichioride with the substituted pyrazolones, RCO$\text{C:C(OH)N(C}{}_6\text{H}{}_5\text{)N:C}$CH₃ (where R = CH₃, C₂H₆, C₆H₅ and p-ClC₆H₄) in the presence of triethylamine in refluxing THF. A possible mechanism for the formation of [(C₅H₄)TiL₂]₂ is suggested.     

Transition metalcarbon bonds: XL. Palladium(II) complexes of [(dimethylamino)methyl]-ferrocene

C₅H₅FeC₅H₄CH₂NMe₂ reacts with sodium chloropalladate(II) in the presence of sodium acetate to give the internally metallated binuclear species [$\text{Pd}{}_2\text{X}{}_2\text{{C}{}_5\text{H}{}_5\text{FeC}{}_5\text{H}{}_3\text{CH}{}_2\text{N}$Me₂}₂] (X = Cl). The corresponding iodide was prepared as were mononuclear species [$\text{Pd(acac) {C}{}_5\text{H}{}_5\text{FeC}{}_5\text{H}{}_3\text{CH}{}_2\text{N}$Me₂}] and [$\text{Pd-{C}{}_5\text{H}{}_5\text{FeC}{}_5\text{H}{}_3\text{CH}{}_2\text{N}$Me₂}L] L = PMe₂Ph, AsMe₂Ph, P(OMe)₃ or PPh₃. ¹H NMR data are given.     

Intramolecular metalation of PBut2Ph and PBut3 in palladium acetate complexes

Reaction of [PdCl₂(PBu^t₂Ph)]₂ with silver acetate gives the internally metalated complex [P$\text{dCH}{}_2\text{CMe}{}_2\text{P}$Bu^tPh]₂(μ-Cl)₂. This reacts with TlC₅H₅ and LiC₅Me₅ with chloride-bridge cleavage to yield C₅R₅P$\text{dCH}{}_2$PBu^tPh (R = H, Me). The complex [P$\text{dCH}{}_2\text{CMe}{}_2\text{P}$Bu^t₂]₂(μ-Cl)₂,prepared from [PdCl₂(PBu^t₃)]₂ and CH₃COOAg, is analogously converted into C₅R₅$\text{PdCH}{}_2\text{CMe}{}_2\text{P}$Bu^t₂. The chloride complex C₅H₅Pd(PBu^t₅Ph)CI does not eliminate HCl to form C₅H₅P$\text{dCH}{}_2\text{CMe}{}_2\text{P}$Bu^tPh.     

The preparation and catalytic hydroformylation activity of some halocarbonylrhodium(I) complexes containing phosphinoalkylorganosilicon ligands

The synthesis and properties of a series of trans-halocarbonylrhodium(I) complexes containing the phosphinoalkylorganosilicon ligands Me₃SiCH₂PPh₂, Me₃Si(CH₂)₃PPh₂, and PPh₂CH₂(Me)$\text{Si(OSiMe}{}_2\text{)}{}_3\text{O}$ have been investigated. The complexes could be prepared by an exchange reaction involving RhCl(CO)(PPh₃)₂ and the organosilicon ligands or in better yields by the reaction of Rh₂Cl₂(CO)₄ with the ligands. Iodorhodium derivatives were obtained as the exclusive products in the latter reaction if a small amount of LiI was present. The catalytic activity of RhCl(CO)(PPh₂CH₂SiMe₃)₂ was similar to that of RhCl(CO)(PPh₃)₂ in the hydroformylation of hex-1-ene at 100°C and 1000 psi pressure of H₂/CO. The catalytic properties of the iodo derivatives RhI(CO)L₂ [L = Me₃SiCH₂PPh₂, Me₃Si(CH₂)₃PPh₂, and PPh₂CH₂(Me)$\text{Si(OSiMe}{}_2\text{)}{}_3\text{O}$] varied considerably, with RhI(CO)(PPh₂CH₂SiMe₃)₂ producing an unexpectedly low linear/branched aldehyde product ratio.