T. Anthony Stephenson

Areneruthenium(II) carboxylates: reactions with ligands and the X-ray structure of the p-cymene pyrazine complex [Ru(η-p-MeC6H4CHMe2)Cl(pyz)2]PF6

The preparation of monomeric areneruthenium(II) acetates and trifluoroacetates [Ru(η-arene)X(O2CR)] and [Ru(η-arene)(O2CR)2](X = Cl or Br; R = Me or CF3; arene = C6H6, p-MeC6H4CHMe2, C6H3Me3-1,3,5, C6H2Me4-1,2,4,5, or C6Me6)(not all possible combinations) from the corresponding dihalides [{Ru(η-arene)X2}2] is described. Infrared spectra suggest that the complexes [Ru(η-arene)X(O2CR)] contain a bidentate carboxylate group and that [Ru(η-arene)(O2CR)2] contain one bi- and one uni-dentate carboxylate group, which are apparently equivalent on the n.m.r. time-scale at room temperature. Reaction of trifluoroacetic acid with [{Ru(η-C6Me6)Cl2}2] gives a complex of empirical formula Ru(η-C6Me6)Cl(O2CCF3)·CF3CO2H which may be a salt [(η-C6Me6)Ru(η-Cl)2(µ-O2CCF3)Ru(η-C6Me6)][H(O2CCF3)2]·CF3CO2H. Triphenylphosphine converts [Ru(η-C6Me6)(O2CR)2](R = Me or CF3) into [Ru(η-C6Me6)(O2CR)2(PPh3)] in which both carboxylate groups are unidentate. The trifluoroacetate group is completely displaced from [Ru(η-C6H6)Cl(O2CCF3)] by pyridine (py) or ethyldiphenylphosphine to give [Ru(η-C6H6)ClL2]+(L = py or PEtPh2), isolated as PF6– or BPh4– salts. The potentially binucleating ligands pyrazine (pyz), 4,4′-bipyridyl, and 1,3-dithiane react either with [Ru(η-C6H6)Cl(O2CCF3)] or with [{M(η-p-MeC6H4CHMe2)Cl2}2](M = Ru or Os) in the presence of NH4PF6 or NaBPh4 in methanol to give [M(η-arene)ClL2]+ salts in which only one donor atom of the ligand is co-ordinated, but pyz and [{Ru(η-p-MeC6H4CHMe2)Cl2}2] react in dry tetrahydrofurane to give the pyrazine-bridged species {Ru(η-p-MeC6H4CHMe2)Cl2}2(µ-pyz). The structure of the complex [Ru(η-p-MeC6H4CHMe2)Cl(pyz)2]PF6 has been verified by X-ray analysis. The crystals are triclinic, space group P, with a= 9.265(2), b= 9.684(4), c= 12.969(2)A, α= 86.51(2), β= 72.89(2), and γ= 85.59(2)°.

STRUCTURAL AND MASS-SPECTRAL STUDIES ON SOME MULTIPLY BONDED DIOSMIUM TETRACARBOXYLATE COMPOUNDS

Abstract The compounds Os 2 (O 2 CCH 3 ) 4 Cl 2 ,1 and Os(O 2 CC 2 H 5 ) 4 Cl 2 , 2, have been structurally characterized. Both compounds crystallize in space group P2 1 /n. For 1 the unit cell parameters are a = 6.546(1) A, b = 8.950(1) A, c = 12.533(1) A, β = 90.17(1)° and Z = 2; for 2 they are a = 6.792(2) A, b = 10.519(3) A, c = 13.372(4) A, β = 89.27(3)° and Z = 2. Both molecules have approximate D 4th symmetry with important dimensions as follows: for 1, Os≡Os 2.314(1) A, OsCl 2.448(2) A; for 2, Os≡Os 2.316(2) A, OsCl 2.430(5) A. The mass spectra of these compounds as well as that of Os 2 (O 2 CC 3 H 7 ) 4 Cl 2 ,3, are reported and discussed.

Platinum-195 NMR studies of Pt(LL)2 (LL = −S2PR2, −S2P(OR)2, −S2CNR2) and their derivatives with phosphorus containing ligands

Abstract Platinum-195 NMR spectra have been recorded for CH2Cl2 solutions of a range of Pt(LL)2 (LL = −S2PR2, −S2P(OR)2, −S2CNR2) and their derivatives with phosphorus containing ligands. Platinum chemical shifts cover a range of almost 2000 ppm.

Ruthenium complexes containing Group 5B donor ligands. Part 5. Synthesis and crystal and molecular structure of acetone(carbonyl)-chloro(trichlorostannio)bis(triphenylphosphine)ruthenium(II)–acetone(1/1)

The lemon-yellow crystals (1) obtained by reaction of the red ‘carbonyl-containing’ ruthenium solution with SnCl2 and PPh3 in acetone have been shown to be [RuCl(SnCl3)(CO)(PPh3)2(OCMe2)]·Me2CO and not [Ru2Cl3(SnCl3)(CO)2(PPh3)2(OCMe2)2](3) as previously suggested. The crystals are monoclinic, space group P21/c with a= 11.950(3), b= 14.988(3), c= 24.916(2)A, and β= 92.51(1)°. The structure has been solved with 3 601 diffractometer data and refined to R 0.037. It is, however, possible to obtain (3) by warming (1) in benzene, but it readily loses SnCl2 to give some [(Ph3P)(OC)ClRuCl3Ru(CO)(PPh3)2].

Carbocyclic complexes incorporating macrocyclic ligands. The synthesis and single crystal X-ray structure of the binuclear species [Rh2(η-C5Me5)2Cl2(L)](BPh4)2(L = 1,4,7,10,13,16-hexathiacyclo-octadecane)

The isoelectronic binuclear arene and C5Me5 platinum metal complexes [Rh2(η-C5Me5)2Cl2(1)]2+ and [M2Cl2(arene)2(1)]2+(M = Ru, arene = C6H6 or 4-MeC6H4Pri; M = Os, arene = 4-MeC6H4Pri)[(1)= 1,4,7,10,13,16-hexathiacyclo-octadecane] have been synthesised; the single crystal X-ray structure of [Rh2(η-C5Me5)2Cl2(1)](BPh4)2 shows a centrosymmetric structure with each RhIII ion bound to two sulphur donor atoms of the hexathia ligand [Rh–S 2.377(1) and 2.365(1)A], one Cl–[Rh–Cl 2.387(1)A], and the C5Me5– ring (mean Rh–C 2.173 A).

Synthesis and reactions of osmium(III) chloro carboxylates. X-ray crystal structure of tetra(µ-n-butyrato)-dichlorodiosmium(III)(Os–OS)

The interaction of the hexachloroosmate(IV) ion, OsCl62–, with acetic acid–acetic anhydride mixtures gives the compound Os2(µ-O2CMe)4Cl2. This brown insoluble paramagnetic compound on treatment with other carboxylic acids forms the exchanged compounds Os2(µ-O2CR)4Cl2(R = Et, Prn, or CH2Cl) that are more soluble in organic solvents. The binuclear bridged carboxylate structure has been established for the butyrate by X-ray diffraction. The crystals are monoclinic, space group P21/n, with a= 6.789(2), b= 11.790(1), c= 14.923(1)A, β= 98.211(18)° and Z= 2. The Os–Os distance is 2.301(1)A and Os–Cl is 2.417(3)A. The interaction of Os2(µ-O2CMe)4Cl2 with various acids, sodium dimethyldithiocarbamate, aromatic amines, tertiary phosphines, and alkyl isocyanides has been studied.

Intra- and inter-molecular stacking in tetracyanoethylene (tcne) complexes of platinum metal dithio acids: The structures and electrochemistry of [Os(S2PR2)2(PPh3)(tcne)] (R = Me, Ph)

The solid-state structure of [Os(S2PR2)2(PPh3)(tcne)](R = Me) shows intermolecular stacking of N-bound tetracyanoethylene (tcne) ligands, whereas for R = Ph intramolecular interaction of co-ordinated tcne and a Ph group of a S2PPh2– moiety is observed; electrochemical reduction of [M(S2PR2)2(PPh3)(tcne)] affords the complex anions [M(S2PR2)2(PPh3)(tcne[graphic omitted])]–(M = Ru, Os; R = Me, Ph, OEt).

Metal complexes of sulphur ligands. Part 15. Reaction of bis[(η-arene)dichlororuthenium] and bis[dichloro(η-pentamethylcyclopentadienyl)metal] complexes of rhodium and iridium with various dithioacid ligands

Reaction of the complexes [{Ru(η-arene)Cl2}2](1)(arene = C6H6 or C6H3Me3) and [{M(η-C5Me5)Cl2}2](2)(M = Rh or Ir) with excess of various dithioacid anions gives monomeric [Ru(η-arene)(S–S)2](3; S–S–=[S2PR2]–) and [M(η-C5Me5)(S–S)2](4: M = Rh, S–S–=[S2PR2]–, [S2CNR2]–, or [S2COR]–; M = Ir, S–S–=[S2CNMe2]– or [S2PMe2]–) respectively. Analytical data together with i.r. and 1H, 13C, and 31P n.m.r. studies show that these complexes contain both bi- and uni-dentate dithioacid groups both in the solid state and in solution. For [M(η-C5Me5)(S2CNMe2)2](M = Rh or Ir) and [Rh(η-C5Me5)(S2COEt)2] in solution at higher temperatures, however, kinetic line-shape analysis indicates the occurrence of uni- and bi-dentate dithioacid exchange probably via a dissociatively controlled intramolecular mechanism. Reaction of (1; arene = C6H6) and (2; M = Rh) with [S–S]–(1 : 1 mol ratio) gives [Ru(η-C6H6)Cl(S2PPh2)] and [Rh(η-C5Me5)Cl(S–S)](5; S–S–=[S2NMe2]–,[S2PMe2]–, or [S2PPh2]–) respectively which are useful precursors for synthesising a range of complexes such as [Rh(η-C5Me5)X(S2CNMe2)](X = Br–, I–, or SCN–) and the mixed dithioacid complexes [Rh(η-C5Me5)(S2CNMe2)(S–S)](6; S–S–=[S2PMe2]–, [S2PPh2]–, or [S2COMe]–). In methanol, (5; S–S–=[S2CNMe2]–) gives the solvated cation [Rh(η-C5Me5)(HOMe)(S2CNMe2)]+ which reacts with various Lewis bases (L) to give [Rh(η-C5Me5)(S2CNMe2)L][BPh4](L = PPh3, PMePh2, CO, AsPh3, or C5H5N). Similar complexes can also be made by reaction of [Ru(arene)Cl2(NC5H5)] or [Rh(η-C5Me5)Cl2(PPh3)] with [S–S]–(1 : 1 mol ratio) and excess of Na[BPh4]. However, reaction of (5; S–S–=[S2CNMe2]–) with excess of Ph2P[CH2]PPh2(dppe) or Ph2PCH2PPh2(dppm) in methanol gives the dimeric cations [{Rh(ηC5Me5)(S2CNMe2)}2(dppe or dppm)]2+(7) and with C2(CN)4 and Na[BPh4] in methanol the cyanotriphenylborate complex [Rh(η-C5Me5)(NCBPh3)–(S2CNMe2)](8) is formed.

Preparation, X-ray crystal structure analysis, and reactions of a novel, hydroxo-bridged, tetranuclear, π-arene ruthenium(II) quadrivalent cation [{(η6-C6H6)Ru(OH)}4](SO4)2·12H2O

Reaction of [{(η6-C6H6)RuCl2}2] with aqueous sodium carbonate (1 : 2 molar ratio) and excess of sodium sulphate gives the title compound (II) whose structure has been determined by X-ray diffraction; a mechanism of formation and some reactions of (II) are also outlined.

Metal complexes of sulphur ligands. Part 19 [1]. Reaction of nickel(II) monothioacetate and -benzoate complexes with somew nitrogen, phosphorus and arsenid donor Lewis bases

Reaction of [{Ni(SOCR)20.5EtOH}] (1) (R = Me, Ph) with various heterocyclic nitrogen donor ligands (L) gives the green, paramagnetic octahedral complexes [Ni(SOCR)2L2] (2) (L = C5H5N, 4-MeC5H4N, 12bipy). In contrast reaction of (1) with various monotertiary phosphines and Ph2P(CH2)xPPh2 (x = 1 or 2) give the red, diamagnetic, square planar, complexes [Ni(SOCR)2(PR′3)2] (3b) (PR′3 = PPh3, PMePh2, PMePh) and [Ni(SOCR)2(Ph2P(CH2)xPPh2)] (3a) respectively, shown by ir spectroscopy to contain unidentate S-bonded −SOCR groups. Molecular weight, electronic spectra and variable temperature 1H and 31P-{1H} nmr studies indicate that the monophosphine complexes (3b), although stable in solution below 220 K, are substantially dissociated at ambient temperature and also in dynamic equilibria with small amounts of paramagnetic isomer. Finally, reaction of (1) with triphenylarsine gives red, paramagnetic complexes [{Ni(SOCR)2AsPh3}n] (H2On (5) believed to be of similar structure to compounds (1) (i.e. n = 2).