Jose Puga

The synthesis of [Ru5C(CO)15] by the carbonylation of [Ru6C(CO)17] and the reactions of the pentanuclear cluster with a variety of small molecules: the X-ray structure analyses of [Ru5C(CO)15], [Ru5C(CO)15(MeCN)], [Ru5C(CO)14(PPh3)], [Ru5C(CO)13(PPh3)2], and [Ru5(µ-H)2C(CO)12{Ph2P(CH2)2PPh2}]

The hexaruthenium cluster [Ru6C(CO)17] reacts with CO at 70 °C and 80 atm to produce [Ru5C(CO)15](1) and [Ru(CO)5]. Complex (1) crystallises in space group P21/c with a= 16.448(3), b= 14.274(2), c= 20.834(4)A, β= 91.36(2)°, and Z= 8. The structure was found to be isomorphous with the analogue [Os5C(CO)15], and was refined to R= 0.051 for 3 256 diffractometer data. The five Ru atoms adopt a square-pyramidal geometry with an exposed carbido-atom lying 0.11 (2)A beneath the basal plane. Reaction of complex (1) with the nitrogen-donor ligand MeCN yields the adduct [Ru5C(CO)15(MeCN)](2) which exhibits a bridged butterfly arrangement of metal atoms with a central carbido-atom. The complex crystallises in space group P21/n with a= 14.116(6), b= 18.167(7), c= 10.276(4)A, β= 95.14(3)°, and Z= 4; the structure was solved by direct methods and difference techniques and refined to R= 0.047 for 1 604 diffractometer data. Reactions of complex (1) with tertiary phosphine ligands PR3[R = Ph (3) or MePh2(4)] or Ph2P(CH2)nPPh2[n= 1 (5) or 2 (6)] produce the substituted complexes [Ru5C(CO)15-m(PR3)m][m= 1 (3a, 4a), 2 (3b, 4b), or 3 (3c, 4c)] or [Ru5C(CO)13{Ph2P(CH2)nPPh2}][n= 1 (5) or 2 (6)]. The structures of these complexes are closely related to that of (1). Complex (3a) crystallises in space group Pn with a= 9.953(2), b= 12.247(2), c= 14.703(3)A, β= 91.23(2)°, and Z= 2, (3b) in space group P21/c with a= 15.923(4), b= 12.494(3), c= 25.210(7)A, β= 93.28(2)°, and Z= 4. Both structures were solved by a combination of direct methods and Fourier techniques and were refined to R= 0.021 for 3 305 reflections (3a) and R= 0.039 for 4 127 reflections (3b), respectively. Hydrogenation of (6) gives the dihydro-complex [Ru5(µ-H)2C(CO)12{Ph2P(CH2)2Ph2}] which crystallises in space group P21 with a= 12.210(4), b= 18.602(6), c= 18.409(6)A, β= 97.63(2)°, and Z= 4. The structure was solved using the same techniques as the other complexes and refined to R= 0.064 for 3 510 diffractometer data. Treatment of complex (1) with halide ions gives the anionic clusters [Ru5C(CO)15X]–(X = F, Cl, Br, or I) whose structures are similar to that of (2). Protonation of these anions gives the monohydrido-clusters [Ru5H(C)(CO)15X]. With Cl2 and Br2 complex (1) undergoes fragmentation to give dimers [Ru2(CO)6X4](X = Cl or Br); in contrast, reaction with I2 gives [Ru5C(CO)15I2].

The synthesis of the first hexaruthenium nitrosyl cluster species; X-ray analysis of Ru6C(CO)14(NO)2 and Ru6C(CO)15(NO)(AuPPh3)

Abstract Reaction of Ru 6 C(CO) 17 with [(PH 3 P 2 N] [NO 2 ] has given the anion [Ru 6 C(CO) 15 (NO)] - (I) which reacts with [NO] + to give Ru 6 C(CO) 14 (NO) 2 (II) and with Ph 3 PAuCl to give Ru 6 C(CO) 15 (NO)AuPPh3 (III); X-ray analysis of II and III confirms the presence of terminal NO-ligands as indicated by the IR spectra, and shows that the AuPPh 3 ligand in III adopts a μ 3 -bonding mode.

Formation of nitride clusters by the action of NO+ on [M4H3(CO)12]–(M = Ru, Os): the synthesis and structural characterization of [Ru4(µ-H)3(CO)11(µ4-N)] and [N(PPh3)2][Os4(CO)12(µ4-N)]

Reaction of [Ru4H3(CO)12]– with NOBF4 in CH2Cl2 give the nitride cluster [Ru4(µ-H)3(CO)11(µ4-N)] as one of the products and in the analogous reaction with [Os4H3(CO)12]– the mono-hydrido complex [Os4(µ-H)(CO)12(µ4-N)] is obtained, which upon subsequent reaction with [N(PPh3)2][NO2] gives the anion [Os4(CO)12(µ4-N)]–; the structures of [Ru4(µ-H)3(CO)11(µ4-N)] and [Os4(CO)12(µ4-N)]– have been established by X-ray analysis.

Synthesis and X-ray structure analysis of the neutral nitrosyl hydrido cluster HRu6C(CO)15(NO)

Abstract Protonation of the anion [Ru 6 C(CO) 15 (NO)] − , formed from the reaction of Ru 6 C(CO) 17 with [N(PPh 3 ) 2 ][NO 2 ], gives the neutral nitrosyl hydrido cluster HRu 6 C(CO) 15 (NO); X-ray analysis shows that the overall structure of this compound is very similar to that of the previously reported derivative Ru 6 C(CO) 15 (NO)(AuPPh 3 ).

Reactions of some decaosmium clusters with electrophilic and nucleophilic reagents: X-ray structure analyses of [N(PPh3)2][Os10C(CO)24(µ-I)], [Os10C(CO)24(µ-I)2], [N(PPh3)2]2[Os10C(CO)22(NO)I], [Os10C(CO)23{P(OMe)3}(µ-I)2] and of two isomers of [Os10C(CO)21{P(OMe)3}4]

The carbido-dianion [Os10C(CO)24]2–(1) reacts with halogens X2 to give firstly [Os10C(CO)24(µ-X)]–, and then [Os10C(CO)24(µ-X)2](X = Cl, Br, or I). The dianion (1) is regenerated on treatment of [Os10C(CO)24(µ-X)]– or [Os10C(CO)24(µ-X)2] with the nucleophiles X–, OH–, PR3(R = OMe or C6H5), C5H5N, MeCN, or CO in polar solvents (tetrahydrofuran, methanol, acetone, or dichloromethane). Treatment of [Os10C(CO)24(µ-I)2](3) with [N(PPh3)2][NO2] in dichloromethane gives the nitrosyl dianion [Os10C(CO)22(NO)I]2–(4). With an excess of P(OMe)3 in xylene, complex (3) gives a mixture of products from which the phosphite-containing clusters [Os10C(CO)23{P(OMe)3}(µ-I)2](5) and [Os10C(CO)21{P(OMe)3}4](6) were separated and identified. The neutral species (5) was shown to react with an iodide ion, in a similar manner to the reaction shown by (3), to sequentially remove the bridging iodine ligands with formation of the dianion [Os10C(CO)23{P(OMe)3}]2–(5b). An isomer of the cluster (6), compound (6a), was prepared by the reaction of [Os10H2C(CO)24] with P(OMe)3 in xylene. Crystal-structure analyses of complexes [N(PPh3)2][Os10C(CO)24(µ-I)], (3), (4), (5), (6), and (6a) are reported and the possible mechanisms for their formation together with a discussion of the factors affecting the reactivity of the Os10 series to nucleophiles are reported.

The [Os3(µ-H)(CO)10(MeCN)2]+ cation: synthesis and X-ray crystal structure of [Os3(µ-H)(CO)10(MeCN)2][Os(CO)3Cl3]

The clusters [Os3(CO)11(MeCN)] and [Os3(CO)10(MeCN)2] react with acids HX (X = BF4 or PF6) to form the cationic derivatives [Os3(µ-H)(CO)11(MeCN)]X and [Os3(µ-H)(CO)10(MeCN)2]X, respectively. The cluster [Os3(CO)10(MeCN)2] also reacts with dry HCl to form the salt [Os3(µ-H)-(CO)10(MeCN)2][Os(CO)3Cl3]. X-Ray analysis of this salt shows that the Os atoms in the cation lie at the vertices of an isosceles triangle. A hydride bridges the long Os–Os edge, and the two acetonitrile ligands occupy trans axial sites. Reaction of [Os3(µ-H)(µ-OH)(CO)10] with HBF4 in MeCN also produces [Os3(µ-H)(CO)10(MeCN)2]+. In this reaction direct attack of H+ on the co-ordinated OH– ligand is considered to occur with the resultant liberation of H2O. Treatment of [Os3(µ-H)(CO)10–(MeCN)2]+ with [Os(CO)4]–2 leads to the formation of the neutral complex [Os4H2(CO)14(MeCN)]. The bridging hydride of the cation may also be replaced by a bridging nitrosyl ligand by reaction with NO+.

The first nitrosyl derivatives of high nuclearity carbonyl clusters: Synthesis and X-ray analysis of the [(Ph3P)2N]+ salts of the anions [Os10C(CO)24(μ2-NO)]− and [Os10C(CO)23(NO)]−

The carbido dianion [Os10C(CO)24]2− reacts with NOBF4 in MeCN to give [OS10C(CO)24(μ2-NO)]− (1) in which the nitrosyl ligand adopts a novel bonding mode bridging the wingtips of a “butterfly” indentation of metal atoms. The anion 1 undergoes rearrangement and CO loss in solution to give [OS10C(CO)23(NO)]− (2); the overall molecular geometry of 2 is close to that previously found for the dianion [Os10C(CO)24]2− with the nitrosyl ligand bonded in a terminal fashion to the tetrahedral Os10 metal skeleton. Crystals of the [(Ph3P)2N]+ salt of 1 are triclinic, space group P1, with a 20.389(4), b 14.670(3), c 12.333(3) A, α 99.55(3), β 94.43(3), γ 103.03(3)°, Z = 2, refinement of atomic parameters using 2699 absorption corrected data converged at R = 0.0952. The [(Ph3P)2N]+ salt of 2 crystallises with one molecule of CH2Cl2 in the triclinic space group P1, with a 19.374(3), b 16.813(3), c 11.791(2) A, α 85.00(3), β 101.81(3), γ 99.43(3)°, Z = 2, refinement of atomic parameters using 8736 absorption corrected data converged at R = 0.0943.

Reaction of [Os4(CO)1 2H3]– with [NO][PF6] in the presence of trace amounts of water; X-ray determination of the molecular structures of [Os4(CO)1 2H3(µ-OPO3H2)] and [Os4(CO)1 2H3(µ-OH)](2 : 1 ratio) in the one crystal

The cluster anion [Os4(CO)1 2H3]– reacts with commercial [NO][PF6] in acetonitrile via the in situ formation of orthophosphoric acid to give the neutral cluster species, [Os4(CO)1 2H4], [Os4(CO)1 2H3(µ-OPO3H2)], and [Os4(CO)1 2H3(µ-OH)]. The latter two products crystallise together in a 2 : 1 ratio in the monoclinic space group P21/c with unit-cell dimensions a= 14.315(3), b= 30.732(4), c= 15.314(3)A, β= 101.48(2)°, and Z= 4. The structure was solved by a combination of direct methods and Fourier-difference techniques and refined by blocked full-matrix least squares to R= 0.051 for 5 091 observed reflections. In each of the µ-OPO3H2 and µ-OH compounds the four osmium atoms define a ‘butterfly’ configuration with two triangles sharing a common edge but which are not coplanar, supported by the bridging oxygen linkage. The three hydrido-ligands were not located but the Os–Os bond lengths suggest that they bridge in the same arrangement as that found previously in [Os4(CO)1 2H3I] by neutron diffraction.

Conversion of a nitrile ligand into an amido group on a cluster surface; X-ray characterisation of [HOs4(CO)12{µ3-N(CO)Me}MPPh3](M = Au or Cu)

The reaction of [H3Os4(CO)12(NCMe)2]+ with [N(PPh3)2]NO2 yields [HOs4(CO)12{µ3-N(CO)Me}]– by a novel conversion of an acetonitrile ligand into an amido group on the cluster surface; the anion reacts with [MPPh3]+(M = Au or Cu) to produce the neutral derivatives [HOs4(CO)12{µ3-N(CO)Me}(MPPh3)] which have been characterised by X-ray diffraction.

Synthesis, reactivity, and spectroscopic studies of some tetranuclear osmium clusters. Structural characterization of [Os4H(CO)12{µ3-NC(O)Me}{M(PPh3)}](M = Au or Cu) and [N(PPh3)2][Os4H2(CO)12I]

The interaction of [Os4H3(CO)12(NCMe)2][BF4](1) with [N(PPh3)2][X](X = NO2, Cl, Br, or l) affords the species [N(PPh3)2][Os4H(CO)12{µ3-NC(O)Me}](2)(X = NO2), [Os4H3(CO)12(µ-X)][X = Cl (6), Br (7), or l (8)], and [N(PPh3)2][Os4H2(CO)12X][X = Cl (9), Br (10), or l (11)] which were characterized by i.r. and 1H n.m.r. spectroscopy. The reaction of complex (1) with nitrite ion results in a novel interaction which involves oxygen transfer from the nitrite ion and conversion of a co-ordinated NCMe ligand into an amido group on the cluster surface. The anionic species (2) reacts with [M(PPh3)]+ to yield the neutral mixed-metal clusters [Os4H(CO)12{µ3NC(O)Me}{M(PPh3)}][M = Au (3) or Cu (4)] which have been structurally characterized by single-crystal X-ray diffractometry. This shows that they possess a butterfly metal framework capped by the heterometallic fragment and µ3-bridged by the four-electron-donor amido group. Complexes (3) and (4) are isomorphous, monoclinic, with space group C2/c and Z= 8: (3), a= 25.681(7), b= 16.069(1), c= 18.265(2)A, and β= 90.90(1)°(4)a= 25.318(6), b= 15.964(5), c= 18.347(7)A, and β= 91.80(2)°. Spectroscopic data suggest that compounds (6) and (7) also possess a butterfly metal framework with a bridging, three-electron-donor, halide ligand, while the anionic species (11) possesses a tetrahedral arrangement of metal atoms with a terminally co-ordinated iodide ligand, as shown by X-ray diffractometry: monoclinic, space group P21/a, Z= 8, a= 16.841(2), b= 20.699(1), c= 29.249(3), and β= 90.91(2)°. Protonation of (11) yields the neutral species [Os4H3(CO)12(µ-l)], showing that facile reversible tetrahedral–butterfly interconversion is assisted by a change in co-ordination mode and electron donation of the l atom. The reaction of compound (11) with CF3SO3R (R = Me or Et) was monitored by 1H n.m.r. spectroscopy and the results explained in terms of the formation of alkyl iodide derivatives.