Stephen D. Robinson

Coordination, oligomerisation and transfer hydrogenation of acetylenes by some ruthenium and osmium carboxylates: Crystal and molecular structures of bis(trifluoroacetato)carbonyl-(methanol) bis(triphenylphosphine)ruthenium(II) and (1,4-diphenylbut-1-en-3-yn-2-yl)trifluoroacetato-(carbonyl) bis(triphenylphosphine)ruthenium(II)

Abstract The hydrides [MH(O2CCF3)(CO)(PPh3)2] (M = Ru or Os) react with disubstituted acetylenes PhCCPh and PhCCMe to afford vinylic products [M{C(Ph)CHPh}(O2CCF3)(CO)(PPh3)2] and [M{C(Ph)CHMe}(O2CCF3)(CO) (PPh3)2]/[M{C(Me)CHPh}(O2CCF3)(CO)(PPh3)2] respectively. Acidolysis of these products with trifluoroacetic acid in cold ethanol liberates cis-stilbene and cis-PhHCCHMe respectively thus establishing the cis-stereochemistry of the vinylic ligands. The complexes [M(O2CCF3)2(CO)(PPh3)2] formed during the acidolysis step undergo facile alcoholysis followed by β-elimination of aldehyde to regenerate the parent hydrides [MH(O2CCF3)(CO)(PPh3)2] and thereby complete a catalytic cycle for the transfer hydrogenation of acetylenes. The molecular structure of the methanol-adduct intermediate, [Ru(O2CCF3)2(MeOH)(CO)(PPh3)2] has been determined by X-ray methods and shows that the coordinated methanol is involved in H-bonding with the monodentate trifluoroacetate ligand [MEO-H---OC(O)CF3; O...O = 2.54 A]. The hydrides [MH(O2CCF3)(CO) (PPh3)2]react with 1,4-diphenylbutadiyne to afford the complexes [M{C(CCPh)CHPh} (O2CCF3)(CO)(PPh3)2]. The ruthenium product, which has also been obtained by treatment of [RuH(O2CCF3)(CO)(PPh3)2] with phenylacetylene, has been shown by X-ray diffraction methods to contain a 1,4-diphenylbut-1-en-3-yn-2-yl ligand. The osmium complexes [Os(O2CCF3)2(CO)(PPh3)2], [OsH(O2CCF3)(CO)(PPh3)2] and [Os{C(CCPh)CHPh}(O2CCF3)(CO)(PPh3)2] all serve as catalysts for the oligomerisation of phenylacetylene. Acetylene reacts with [Ru(O2CCF3)2(CO)(PPh3)2] in ethanol to afford the vinyl complex [Ru(CHCH2)(O2CCF3)(CO)(PPh3)2].

Catalytic dehydrogenation of primary and secondary alcohols by Ru(OCOCF3)2(CO)(PPh3)2

Abstract The complex Ru(OCOCF 3 ) 2 (CO)PPh 3 ) 2 is an efficient homogeneous catalyst for the dehydrogenation of primary and secondary alcohols to aldehydes and ketones respectively; a mechanism involving a “β-elimination” step is proposed.

Transition-metal complexes containing phosphorus ligands. Part XI. Cationic trialkyl phosphite derivatives of gold, silver and the platinum metals

Abstract Ligand exchange reactions performed in polar solvents afford a convenient general route to an extensive series of cationic trimethyl and triethul phosphite derivatives of gold, silver and the platinum metals, which were islated as theri tetraphenylborate salts. The products, which were characterised by elemental analysis, proton n.m.r. spectroscopy and conductivity measurements, contain cations of the general formulae {M[P(OR)3]6}2+ (M = Ru, Os);{MX[P(OR)3]5}+ (M = Ru, X = H, Cl, Br, M = Os, X = Br);{M[P(OR)3]5}+ (M = Rh, Ir); {M[p(OR)3]4}2+ and{MCl[P(OR)3]3}+ (M = Pd, Pt) and {M[p(OR)3]4}+ (M = Ag, Au) (R = Me or Et throughout). A qualitative description of the coupling patterns observed in the proton n.m.r. spectra of these cations is given, and is interpreted in terms of ligand rearrangement, exchange and dissociation processes.

1,3,4,-Thiadiazole-2,5-dithiol complexes of the platinum group metals; the molecular structure of carbonylbis(1,3,4-thiadiazole-2,5-dithiolato)bis(triphenylphosphine)ruthenium(II)

Abstract The precursors MH 2 (CO)(PPh 3 ) 3 (M = Ru or Os), Ru(CO) 3 (PPh 3 ) 2 /OsH 2 (CO) 2 (PPh 3 ) 2 and IrH(CO)(PPh 3 ) 3 react with 1,3,4-thiadiazole-2,5-dithiol (tddtH 2 ) in boilig toluene to afford the 1,3,4-thiadiazole-2,5-dithiolato (tddtH) complexes M(tddtH) 2 (CO)(PPh 3 ) 2 , M(tddtH) 2 (CO) 2 (PPh 3 ) 2 and IrH(tddtH) 2 (CO)(PPh 3 ) 2 respectively. The molecular structure of the ruthenium complex Ru(tddtH) 2 (CO)(PPh 3 ) 2 has been determined by X-ray diffraction methods, the crystals are triclinic space group P 1 , Z = 2, unit cell dimensions are a = 13.051(3), b = 16.404(7), c = 16.500(5) A, α = 119.60(2), β = 91.46(2), γ = 104.21(3)°, ( V = 2932.0(16) A 3 . The structure contains octahedral ruthenium(II) with mon-dentate (S-coordinated) and bi-dentate (N,S-coordinated) tddtH ligands, a carbonyl group and a trans pair of triphenylphosphine ligands. The complexes M(tddtH) 2 (CO)(PPh 3 ) 2 and the closely related ruthenium 5-methyl-1,3,4-thiadiazole 2-thiolato complex Ru(mtdt) 2 (CO)(PPh 3 ) 2 have been shown by 1 H NMR to display dynamic interchange of mono- and bi-dentate thiolate ligands. Some rhodium(I), palladium(0) and platinum(0) complexes of tddtH 2 are tentatively reformulated.

Coordination, Oligomerisation and Transfer Hydrogenation of Acetylenes by Some Ruthenium and Osmium Carboxylato Complexes: Crystal and Molecular Structure of (1,4-Diphenylbut-1-en-3-yn-2-yl)trifluoroacetato(carbonyl) bis(triphenylphosphine)ruthenium(II)

Abstract The complexes (MH(O2CCF3) (CO) (PPh3)2] and (M(O2CCF3)2(CO)(PPh3)2] (M = Ru or Os) react with terminal and internal acetylenes to afford oligomerisation and hydrogenation products, respectively, together with vinylic complexes, including the ruthenium species [Ru(C4HPh2)(O2CCF3)(CO) (PPh3)2], which has been shown by x-ray diffraction methods to contain a 1,4-diphenylbut-1-en-3-yn-2-yl ligand.

Complexes of the platinum metals. Part 22 [1]. Synthesis and molecular dynamics of 1,3-diaryltriazenido derivatives

Abstract 1,3-Diaryltriazenes, ArN = NNHAr (Ar = Ph, p-MeC6H4 and p-MeOC6H4) react with platinum metal halide complexes in the presence of triethylamine to afford products containing mono- or bi-dentate (chelate or bridging) 1,3-diaryltriazenide ligands. Complexes prepared in this manner include derivatives of ruthenium(II), 2(PPh3)2] and (CO)(PPh3)2]; rhodium(I), 2], (C8H12)(PPh3)] and (CO)(PPh3)2]; palladium(II) L2] (X = Cl, L = PPh3, PEt3, AsPh3, PMePh2; X = Br, L = PMePh2; X = I, L = PMe2Ph), and 2(PMe2Ph)2]; and platinum(II(, [PtCl L2] (L = PPh3, PEt3, and PEt2Ph; L = C8H12). The intramolecular N(1)–N(3) exchange process: displayed by the monodentate 1,3-diaryltriazenido derivatives of rhodium(I), palladium(II) and platinum(II) have been studied by dynamic proton NMR spectroscopy, and thermodynamic parameters of activation have been determined. ΔH≠ values were found to lie within the range ca. 32–44 kJ mol−1 for the palladium(II) and platinum(II) complexes, ΔS≠ values are all negative.

1,3-diaryltriazenido complexes of ruthenium(I), (II) and (III), and of osmium(III), rhodium(III) and iridium(III)

Abstract The synthesis and characterization of the platinum metal—1,3-diaryltriazenido complexes [Ru(ArNNNAr)(CO) 3 ] 2 , [Ru(ArNNNAr) 2 ] 2 , cis -Ru(ArNNNAr) 2 (CO) 2 , MX 2 (ArNNNAr)(PPh 3 ) 2 (M = Ru, Os; X = Cl, Br) and M′(ArNNNAr) 3 (M′= Ru, Os, Rh and Ir) are reported. Axial ligand substitution in [Ru(ArNNNAr)(CO) 3 ] 2 and adduct formation by [Ru(ArNNNAr) 2 ] 2 are described. In contrast to other known Ru(II)/Ru(II) “lantern” molecules, the species [Ru(ArNNNAr) 2 ] 2 have measured magnetic moments equivalent to ca one unpaired electron per dimer, which are presumably due to population of the spin states σ 2 π 4 δ 2 π *4 and σ 2 π 4 δ 2 π *3 σ *1 .

Complexes of the platinum metals. XXXIV: Synthesis and characterization of some binuclear ruthenium(I/I) triazenido complexes: X-ray crystal structure of tetracarbonylbis (μ-1,3-di-p-tolyltriazenido)bis(p-toluidine) diruthenium(I/I)

Abstract The ruthenium(I) triazenido complexes [Ru(ArNNNAr)(C0)3]2 (Ar = p-C6H4Me or p-C6H4Cl) have been prepared by heating RU3(CO)12 with free triazene in benzene under a carbon monoxide atmosphere, and by heating [Ru(O2CMe)(CO)2]n with free triazene and triethylamine in acetonitrile under carbon monoxide. Reactions of the diruthenium(I/I) triazenido complexes with PPh3, P(OME)3 or ArNNNHAr (Ar =p-C6H4Cl) afford axial substitution products of the general form [Ru(ArNNNAr)(CO)2L]2. However, with ArNNNHAr (Ar = p-C6H4Me) cleavage of triazene to generate axial p-toluidine ligands occurs. The structure of the p-toluidine adduct, [Ru(ArNNNAr)(CO)2(NH2Ar)]2 has been determined by X-ray diffraction methods. The compound crystallizes in space group P 1 with a = 11.350(1), b = 20.582(4), c= 10.371(5) A, α = 100.75(4), β = 104.30(3), γ = 84.40(1)°; U = 2303.89 A3 and Z = 2.

X-ray crystal and molecular structure of sulphato aquotris(benzotriazole) copper(II)benzotriazole

Abstract The complex “Cu(SO4)(btaH)4·2H2O” (btaH = benzotriazole) deposited as deep blue crystals from aqueous CuSO4·5H2OH2SO4btaH solutions been shown by X-ray diffraction methods to be a monohydrate [Cu(SO4)(H2O)(btaH)3·btaH]. The crystals contain five-coordinate, tetragonal pyramidal Cu(SO4)(H2O)(btaH)3 units and bridging btaH molecules linked together by a three-dimensional array of H-bonding interactions.

Complexes containing phosphorus lignads—161: New phosphinite, phosphonite and phosphite derivatives of ruthenium, osmium and iridium

The complexes [MHCl(CO)(PPh3)3] (M = Ru or Os) readily undergo substitution at the site trans to the hydride ligand to afford phosphinite-, phosphonite-, or phosphite-containing products [MHCI(CO)(PPh3)2L] [L = P(OR)Ph2, P(OR)2Ph or P(OR)3 respectively; R = Me or Et]. The ruthenium complexes alone undergo further substitution to afford complex cations [RuH(CO)(PPh3)nL4−n]+ [n = 2, L = P(OMe)3; n = 1, L = P(OR)3; n = 0, L = P(OR)2Ph or P(OR)Ph2] which were isolated and characterised as their tetraphenylborate salts. Synthesis of the cationic complexes [IrHL5][BPh4]2 [L = P(OR)3, R = Me or Et] is also reported. Stereochemical assignments based on NMR data are given, and second order 31P and high field 1H NMR patterns are analysed.