Synthesis of cationic dialkylgold(III) complexes: nature of the facile reductive elimination of alkane

A series of gold(III) cations of the type cis-[CH₃)₂AuL₂]⁺ X^? where L  Ph₃, PMePh₂, PMe₂Ph, PMe₃, AsPh₃, AsPh₃, SbPh₃, $\text{1}\text{2}$H₂NCH₂CH₂NH₂, $\text{1}\text{2}$ Ph₂PCH₂CH₂-PPh₂, $\text{1}\text{2}$ Ph₂AsCH₂CH₂AsPh₂, and $\text{1}\text{2}$o-C₆H₄(AsMe₂)₂ and X  BF₄^?, PF₆^?, ClO₄^?, and F₃CSO₃^? has been prepared. In addition, the cis complexes [(CH₃)(CD₃)-Au(PPh₃)₂]F₃CSO₃, [(C₂H₅)₂Au(PPh₃)₂]F₃CSO and [(n-C₄H₉)₂Au(PPh₃)₂]F₃-CSO₃ have been synthesized. All have been characterized by PMR, Raman and infrared spectroscopy. These [R₂AuL₂]X compounds yield only ethane, butane, or octane via reductive elimination, and no disproportionation is observed. The alkane eliminations have been studied in CHCl₃, CH₃Cl₂, and CH₃COCH₃ solution as a function of temperature, concentration of the complex, and concentration of added ligand L. Elimination is fastest when L is bulky (PPh₃ > PMePh₂ > PMe₂Ph > PMe₃), decreases in the sequence SbPh₃ > AsPh₃ > PPh₃, is slow with chelating ligands, is inhibited by excess ligand, and there is small anion effect as X is varied. As R is varied, the rate of elimination decreases Bu ? Et > Me. An intramolecular dissociative mechanism is proposed which involves rapid elimination of alkane from an electron deficient dialkylgold(III) complex with nonequivalent gold—carbon bonds and produces the corresponding [AuL₂]X complex.     

Fulvene—platinum complexes: x-ray crystal structure of [Pt(η2-C5H4CPh2)(PPh3)2]

Bis(cycloocta-1,5-diene)platinum reacts with 2,3,4,5-tetraphenylfulvene to afford the complex [Pt(η²-CH₂C₅Ph₄)(cod)] (cod  C₈H₁₂) in which the metal atom is coordinated to the exo-cyclic double bond of the fulvene. Related compounds [Pt(η²-CH₂C₅Ph₄L₂] (L  PPh₃, PMePh₂, PMe₂Ph, AsPh₃ or CNBu^t have also been prepared and characterised. Reaction of the complexes [Pt(C₂H₄)₂(L)] (L  P(cyclo-C₆H₁₁)₃, PPh₃ or AsPh₃) with 2,3,4,5-tetraphenylfulvene yields the compounds [Pt(C₂H₄)(η²-CH₂C₅PH₄)(L)]. NMR data for the new species are reported and discussed. 6,6-Diphenylfulvene reacts with [Pt(cod)₂] and PPh₃ ($\text{1}\text{2}$ mol ratio) to give the complex [Pt(η²-C₅H₄CPh₂)-(PPh₃)₂] in which the metal atom is bonded to carbon atoms C(2) and C(3) of the fulvene ring. This was established by an X-ray diffraction study. Crystals are monoclinic, space group P2₁/n, with Z  4 in a unit cell of dimensions a  13.761(4), b  21.653(13), c  17.395(6) Å, β,  104.46(2)°. The structure has been solved and refined to R  0.064 (R′  0.064) for 3139 independent diffracted intensifies measured at room temperature. The platinum atom is in a trigonal environment formed by the two ligated phosphorus atoms and the CC bond of the fulvene which is elongated to 1.52(3) Å. The c₅ fulvene ring is planar, and makes an angle of 108° with the coordination plane around the platinum. In this plane the metal atom is slightly asymmetrically bonded with PtC 2.15(2) and 2.24(2) Å, and PtP 2.280(6) and 2.301(6) Å.     

Synthesis and characterisation of new triple halide-bridged mixed valence binuclear complexes of ruthenium and osmium

Several isomers of the type [M₂Cl₅L₄] (M = Ru, L = AsPh₃, As(p-tol)₃, As(p-PhCl)₃, PEt₂Ph, PMe₂Ph; L₂ = Ph₂As(CH₂)₂AsPh₂; M = Os, L = PPh₃, AsPh₃) have been synthesised by various routes and characterised by magnetic, ESR and electrochemical measurements, and for [(PEt₂Ph)Cl₂RuCl₃Ru(PEt₂Ph)₃] by X-ray structural analysis.     

Carbonyl complexes of manganese(I) with chelating phosphino-alkyl or -acyl ligands. Crystal and molecular structure of [Ph2PCH2CH2(O)CMn(CO)2(dppm)l

The phosphine Ph₂PCH₂CH₂Cl reacts with fac-[XMn(CO)₃(dppm)] (X = Cl or Br) in refluxing toluene to give the complexes cis,cis-[XMn(CO)₂(dppm)(Ph₂PCH₂CH₂Cl)] (I). Treatment of those species with Na amalgam in THF leads to the alkyl complex [Ph₂$\text{PCH}{}_2\text{CH}{}_2\text{M}$n(CO)₂(dppm)] (II), which does not react with CO under normal conditions but can be converted into cis,cis-[ClMn(CO)₂(dppm)(PPh₂Et)] by reacting with HCl (g) in ether. If the reduction of I with Na/Hg is carried out in the presence of CO the compound cis-[Ph₂$\text{PCH}{}_2\text{CH}{}_2\text{(O)CM}$n(CO)₂(dppm)] (III) is obtained. The latter has also been prepared directly from fac-[BrMn(CO)3(dppm)], Ph₂PCH₂CH₂Cl, and Na/Hg in THF, and characterized by X-ray crystallography. The crystals are monoclinic, space group P2₁/n; refinement gave R = 0.053 for 2593 reflections with I ? 2.5σ(I). The reaction of the complex fac-[O₃ClOMn(CO)₃(dppm)] with Ph₂PCH₂CH₂Cl in Cl₂CH₂ gives the salt fac-[Mn(CO)₃(dppm)(Ph₂PCH₂CH₂Cl)]ClO₄ which isomerizes to mer-[Mn(CO)₃(dppm)(Ph₂PCH₂CH₂Cl)]ClO₄ in boiling butanol. Both cationic carbonyl complexes give the acyl species III upon reduction with Na amalgam.     

Zur Kenntnis der Chemie der Metallcarbonyle und der Cyano-Komplexe in flüssigem ammoniak : XL. Über die Reaktion kationischer Cyclopentadienyl-carbonyl-nitrosyl-Komplexe des Mangans und Rheniums mit flüssigem Ammoniak

The reactions of the cationic complexes [CpMn(CO)₂NO]⁺, [MeCpMn(CO)₂NO]⁺ (Cp = η⁵-C₅H₅, MeCp = η⁵-C₅H₄CH₃), [CpRe(CO)₂NO]⁺, [CpMn(CO)(L)NO]⁺ (L = PPh₃, PEt₂Ph, AsPh₃, CNMe, CNEt), {[CpMn(CO)NO]₂Me₂PC₂H₄PMe₂}²⁺ and {CpMn(CO)NO]₂Ph₂PC₂H₄PPh₂}²⁺ with liquid NH₃ yield the neutral carbamoyl complexes CpMn(CO)(NO)CONH₂, MeCpMn(CO)(NO)CONH₂, CpRe(CO)(NO)CONH₂, CpMn(L)(NO)CONH₂ (L = PPh₃, PEt₂Ph, AsPh₃, CNMe, CNEt), [CpMn(NO)CONH₂]₂Me₂PC₂H₄PMe₂ and [CpMn(NO)CONH₂]₂Ph₂PC₂H₄PPh₂. Properties and reactions of these new compounds are described.     

Hydrido- and hydroxo-cyanoalkyl complexes of platinium(II). Reactivity of the PtH and PtOH bonds towards nucleophiles and electrophiles

Reactions of the PtH and/or PtC bonds of the hydridocyanoalkyl complexes cis- or trans-PtH[(CH₂)_nCN]L₂ (n = 1, 3; L₂ = 2 PPh₃, Ph₂PCHCHPPh₂) are described, viz. reductive elimination induced by CO, PhCCPh, PEt₃, PPhMe₂, cis-Ph₂PCHCHPPh₂ to give Pt(CO)₂L₂, PtL₂(PhCCPh), PtL₂, PtL(PPhMe₂)₃, PtL₂(Ph₂PCHCHPPh₂) (L = PPh₃), respectively, and cleavages by acids, halogens and alkyl halides.The monomeric hydroxo complexes cis-Pt(OH)[(CH₂)_nCN]L₂ were shown to be intermediates in the synthesis of PtH[(CH₂)_nCN]L₂ from cationic cyanoalkyl complexes in alcoholic NaOH. Their characterisation and the reactions of the PtOH bond with activated methyl groups are reported.     

Chemie polyfunktioneller moleküle: LXXVI. Metallcarbonyl-, metallnitrosylcarbonyl-und metallnitrosyl-komplexe des bis(diphenylphosphino)amins

The compound Ph₂PN(H)PPh₂ (I) reacts under special conditions with M(CO)₆ (M  Cr, Mo), Fe(NO)₂(CO)₂ and Co(NO)(CO)₃ to give the new complexes cis-M(CO)₂[Ph₂PN(H)PPh₂]₂ (III, IV), [Fe(NO)₂(CO)Ph₂P]₂NH (V), [Fe(NO)₂Ph₂-PN(H)PPh₂]₂ (VI) and Co(NO)(CO)₂Ph₂PN(H)PPh₂ (VII). Compound VI can also be prepared reacting V with I. For III and IV proton NMR spectra indicate some interaction between o-protons of the phenyl rings and cis-M(CO)₂ groups. VI exists an eight-membered ring complex without a metal-metal bond. On the basis of spectroscopic data VII seems to exist in two conformers.     

Metal Ions in Biological Systems,Volume 4. Metal Ions as Probes; : edited by Helmut Sigel,Marcel Dekker,New York, 1974, xii + 261 pages, $24.75.

Trends in ³¹P NMR coordination shifts for the complexes M(CO)₃BrL₂, [M(CO)₃L₂(NCMe)]⁺, MeC₅H₄Mn(CO)L₂ and [MeC₅H₄Mn(CO)₂]₂L₂ (M = Mn and Re;L₂ = Ph₂PCH₂PPh₂, Ph₂PCH₂CH₂PPh₂ and Ph₂PCH₂CH₂AsPh₂) are discussed.     

Studien zur CH-aktivierung: II. Der einfluss der liganden auf die bildung von aryl(hydrido)ruthenium(II)- und -osmium(II)-komplexen aus aromaten

The complexes trans-MCl₂(PMe₃)₄ (M = Ru, Os) react with CO and P(OMe)₃ to give the mono- and disubstituted derivatives trans,mer-MCl₂(PMe₃)₃L (L = CO, P(OMe)₃) and all-trans-MCl₂(PMe₃)₂[P(OMe)₃]₂, respectively. On reaction of trans-RuCl₂[P(OMe)₃]₄ with CO and PMe₃, the compounds trans,mer-RuCl₂[P(OMe)₃]₃(CO) and trans,cis,cis-RuCl₂(PMe₃)₂[P(OMe)₃]₂ are synthesized. The reduction of MCl₂(PMe₃)₂[P(OMe)₃]₂ with Na/Hg in benzene or toluene via {M(PMe₃)₂[P(OMe)₃]₂} as an intermediate leads to subsequent intermolecular addition of the arene and to the aryl(hydrido)metal complexes cis,trans,cis-MH(C₆H₅)(PMe₃)₂[P(OMe)₃]₂ (M = Ru, Os) and MH(C₆H₄CH₃)(PMe₃)₂[P(OMe)₃)₂ (M = Os). For M = Ru, in the presence of P(OMe)₃, the ruthenium(0) compound Ru(PMe₃)₂(P(OMe)₃]₃ is formed. The hydrido(phenyl) complexes react with equimolar amounts of Br₂ or I₂ by elimination of benzene to produce the dihalogenometal compounds cis,trans,cis-MX₂(PMe₃)₂[P(OMe)₃]₂. The reaction of trans-RuCl₂(PMe₃)₄ with Na/Hg in the presence of PPh₃ leads to the ortho-metallated complex fac-RuH(η²-C₆H₄PPh₂)(PMe₃)₃, which reacts with CH₃I, CS₂, COS and HCl to give the compounds mer-RuI(η²-C₆H₄PPh₂)(PMe₃)₃, fac-Ru(SCHS)(η²-C₆H₄PPh₂)(PMe₃)₃, fac-Ru(S₂CO)(CO)(PMe₃)₃ and RuCl₂(PMe₃)₃, respectively. The paramagnetic 17-electron complexes [MCl₂(PMe₃)_nL_4-n]PF₆ are obtained on oxidation of MCl₂(PMe₃)_nL_4-n with AgPF₆. Their UV spectra exhibit a characteristic CT band. [RuCl₂(PMe₃)₄]PF₆ and [OsCl₂(PMe₃)₄]PF₆ react with CO and P(OMe)₃ by reduction to form the corresponding ruthenium(II) and osmium(II) compounds MCl₂(PMe₃)_nL_4-n.     

Cyanoalkyl complexes of transition metals . : II. Preparation and properties of some platinum complexes containing phosphorus as a donor atom

cis-PtCl(CH₂CN)(PPh₃)₂ was obtained by the reaction of Pt(PPh₃)₄ with ClCH₂CN in acetone. A solution of Pt(PPh₃)₄ and ClCH₂CN in benzene was heated under reflux to give trans-PtCl(CH₂CN)(PPh₃)₂. The reaction of the trans-isomer with Br^?, I^?, Ph₂PCH₂CH₂ PPh₂, Ph₂PCH₂CH₂AsPh₂ and cisPh₂PCHCHPPh₂ has been examined. The trans-influence of a ligand trans to the CH₂CN group seems to be indicated by the ²J(PtH) of the CH₂CN protons. The τ values of trans-PtX(CH₂CN)(PPh₃)₂ and PtX(CH₂ CN)(PP) (X = Cl, Br, I) are related by a linear function.     

Molybdenum and tungsten complexes with the heteroallyl-like Ph2P(O)C(S)NR− (R  Me,Ph) as ligand. X-ray structural analysis of Mo(CO)2(PPh3)(Ph2P(O)C(S)NPh)2 · CH2Cl2; A 4 : 3 piano-stool configuration

Ph₂P(O)C(S)N(H)R (R  Me, Ph) reacts with M(CO)₃(η⁵-C₅H₅)Cl (M  Mo, W) in the presence of Et₃N to give M(CO)₂(η⁵-C₅H₅)(Ph₂P(O)C(S)NR). The deprotonated ligand coordinates in a bidentate manner through N and S to give a four-membered ring system. M(CO)₃(PPh₃)₂Cl₂ (M  Mo, W) reacts with Ph₂P(O)C(S)N(H)R (R  Me, Ph) in the presence of Et₃N to give complexes in which the central metal atoms are seven coordinate through two ligands bonded via O and S to form five-membered ring systems, one PPh₃, and two CO groups. The complexes were characterised by elemental analyses, IR, ¹H NMR, and ³¹P NMR spectroscopy, and an X-ray structural analysis of Mo(CO)₂(PPh₃)(Ph₂P(O)C(S)NPh)₂ · CH₂Cl₂.     

Komplexkatalyse : VII. Zur bildung von chloro-nitrosyl-dicarbonyl-molybdän(0)-komplexen bei der reaktion von dichloro-dinitrosyl- und trichloro-mononitrosyl-molybdän-verbindungen mit C2H5AlCl2 und kohlenmonoxid

The preparative isolation of the chloronitrosyldicarbonylmolybdenum(0) complexes MoCl(NO)(CO)₂L₂ (L = PPh₃, AsPh₃) from solutions of MoCl₃(NO)/6 C₂AlCl₂/CO in CH₂Cl₂ is described. From this it might be concluded that the catalytic active complex for olefin metathesis generated from dichlorodinitrosyl- or trichloromononitrosyl-molybdenum compounds with C₂H₅AlCl₂ could be a NO containing species.     

Photochemical reactions of Re(CO)5Br with Ph2P(CH2) n PPh2 (n = 1, dppm; 2, dppe; 3, dppp)

The new complexes fac-[Re(CO)₃Br{Ph₂P(CH₂) _n PPh₂}] (1a–3a) [(1a), n = 1; (2a), n = 2; (3a), n = 3] and [Re₂(CO)₈Br₂{-Ph₂P(CH₂) _n PPh₂}] (1b–3b) [(1b), n = 1; (2b), n = 2; (3b), n = 3] have been prepared by the photochemical reaction of Re(CO)₅Br with Ph₂P(CH₂) _n PPh₂ (n = 1, dppm; 2, dppe; 3, dppp). The complexes have been characterized by elemental analysis, mass spectroscopy, f.t.-i.r. and ³¹P-[¹H]-n.m.r. spectrometry. The spectroscopic studies suggest cis-chelate bidentate coordination of the ligand in fac-[Re(CO)₃Br{Ph₂P(CH₂) _n PPh₂}] (1a–3a) and cis-bridging bidentate coordination of the ligand between two metals in [Re₂(CO)₈Br₂{cis--Ph₂P(CH₂) _n PPh₂}] (1a–3a).     

Disubstituted vinylidene complexes of iron and ruthenium: nucleophilic properties of ν1-acetylide ligands

The η¹-acetylide complexes (C₅H₅)ML₂(CCR) (M  Fe, Ru; L  PPh₃, L₂  Ph₂PCH₂CH₂PPh₂) are nucleophilic at the β-carbon and react with a variety of mild electrophiles to yield the corresponding disubstituted vinylidene complexes [(C₅H₅)ML₂ (CCR′) PF₆.     

Substitution reactions of trans-[PdXPh(SbPh3)2J (X=Cl or Br) with nitrogen,phosphines and arsenic donor ligands. Crystal structures of trans-[PdClPh(PPh3)2], [PdClPh(bipy)], [PdClPh(dppm)]2, and [PdBrPh(dppm)]2

Exchange reactions of trans-[PdXPh(SbPh₃)₂] (1) (X=Cl or Br) with ligands L in refluxing dichloromethane give the palladium phenyl complexes [PdXPhL₂] (X=Cl, L=PPh₃, AsPh₃, L₂=2,2′-bipyridine (bipy), 4,4′-dimethyl-2,2′-bipyridine (dmbipy), 1,10-phenanthroline (phen); X=Br, L=PPh₃, L₂=bipy). Treatment of the complexes with bis(diphenylphosphino)methane (dppm) in refluxing dichloromethane gives [PdXPh(dppm]₂. These complexes have been characterised by microanalysis, IR and ¹H NMR spectroscopic data together with single crystal X-ray determinations of the phenyl palladium complexes, trans-[PdClPh(PPh₃)₂], [PdClPh(bipy)], [PdClPh(dppm)]₂, and [PdBrPh(dppm)]₂.     

Stepwise reduction of the thiocarbonyl ligand: hydride transfer to CS: thioformyl,thioformaldehyde, methylthiolato,secondary carbene,formyl and iminoformyl complexes of osmium

The complexes OsHX(CS)L(PPh₃)₂ (X  Cl, Br; L  CO and X  Cl; L  CN-p-tolyl), which contain mutually cis hydrido and thiocarbonyl ligands, undergo transfer of the hydrido ligand to CS when treated with CO to give blue complexes containing the thioformyl ligand [OsCHS]. OsCl(CHS)(CO)₂(PPh₃)₂ reacts with borohydride to give the first metal complex of the thioformaldehyde monomer, viz. Os(η²-CH₂S)(CO)₂(PPh₃)₂, which reacts rapidly with HCl to give OsCl(SCH₃)(CO)₂(PPh₃)₂ and then, by a slower reaction, OsCl₂(CO)₂(PPh₃)₂ and CH₃SH. The ligands produced in this stepwise reduction have possible relevance as models for postulated intermediates in the Fischer—Tropsch synthesis. Synthetic routes to formyl [OsCHO], iminoformyl [OsCHNMe] and secondary carbene complexes [OsCHSMe, OsCHNMe₂, OsCHOMe] are also demonstrated.     

Cationic Carbonyl complexes of manganese(I) with diphosphines

The bromo-carbonyls fac-BrMn(CO)₃(diphos)(diphos  Ph₂P(CH₂)_nPPh₂ for n = 1(dpm), 2(dpe), 3(dpp) and 4(dbp)) react with AgClO₄ in dichloromethane solution to give the neutral fac-O₃ClOMn(CO)₃(diphos). The reaction of the latter complexes at room temperature with a variety of ligands L  phosphines (PR₃), phosphites (P(OR)₃), pyridine (Py), acetonitrile (MeCN), tetrahydrothiophene (THT) or acetone (Me₂CO) leads to the cationic species fac-[Mn(CO)₃(diphos)L]ClO₄ (or to the [Mn(CO)₄(diphos))]ClO₄, when L  CO). When L is a phosphorus ligand, the cationic fac-tricarbonyls isomerize upon heating to the mer isomers, which could only be isolated by this method for diphos  dpm, the reaction being accompanied by decomposition in the other cases. UV irradiation of the mer-[Mn(CO)₃(diphos)L]ClO₄ in the presence of a large excess of L gives the corresponding trans-[Mn(CO)₂(diphos)L₂]ClO₄.     

Reactions of (η-allyl)dicarbonylmolybdenum(II) complexes with phosphorus and arsenic donor ligands

Reaction of [MoX(CO)₂(η-C₃H₅)(MeCN)₂] with the arsines Ph₂AsCH₂CH₂AsPh₂ (dae) and Ph₂AsCH₂AsPh₂ (dam) yields complexes of stoichiometry [MoX(CO)₂(η-C₃H₅)dae] (where X = Cl, Br or I) and [MoX(CO)₂(η-C₃H₅)]₂dam (where X = Cl or Br). The former are isomorphous with the known Ph₂PCH₂CH₂PPH₂ complexes, whereas the latter probably contain halogen and dam bridges. Under forcing conditions the corresponding ditertiary phosphines form the molybdenum(0) derivatives $\text{cis}$-Mo(CO)₂(Ph₂P(CH₂)_nPPh₂]₂ (where n = 1 or 2).     

The synthesis,characterization and reactions of a binuclear tetramethylplatinum(IV) complex

Reaction of excess MeLi and MeI with [PtCl₂SMe₂)₂] gives the first binuclear tetramethylplatinum(IV) complex [Pt₂Me₈(μ-SMe₂)₂]. The characterization of this complex, and its reactions with donor ligands to give cis-[PtMe₄L₂] (L₂ = Ph₂PCH₂PPh₂, Ph₂PCH₂CH₂PPh₂, 2,2′-bipyridyl, 1,10-phenanthroline or L = PMe₂Ph, PMePh₂) are described.     

Coordinating Properties of Dipod and Tripod Phosphorus Ligands with Separated Donor and Acceptor Sites

Abstract

The coordinating properties of dipod and tripod phosphorus ligands L_I = R₂M′ (OCH₂PMe₂) _n(CH₂CH₂PMe₂) _2-n and L_II = RM′ (OCH₂PMe₂)_n(CH₂CH₂PMe₂)_3-n (M′ = Si, Ge) with separated donor and acceptor centres have been investigated using electron rich metal complex fragments, e. g. M(CO)_m, (M = Cr, MO, W), π-C₅H₅Co, RhCl(CO) or Ni(CO), as bonding partners.