M. Pilar Gómez-Sal

Benzene in a new face-capping bonding mode: molecular structures of [Ru6C(CO)11(µ3-η2: η2:η2-C6H6)(η6-C6H6)] and [Os3(CO)9(µ3-η2: η2:η2-C6H6)]

A new co-ordination mode for benzene ligands in cluster complexes, in which the ring is symmetrically placed above a metal triangle has been crystallographically established in the carbonyl complexes [Ru6C(CO)11(µ3-η2: η2:η2-C6H6)(η6-C6H6)] and [Os3(CO)9(µ3-η2: η2:η2-C6H6)].

The electrochemical reduction of an unsaturated mixed-metal cluster anion: Synthesis and x-ray crystal structure of [(Ph3P)2N][{Os3H(CO)10}2Ag]

Abstract The unsaturated mixed-metal cluster anion [{Os 3 H(CO) 10 } 2 Ag] − has been prepared by the reaction of [(Ph 3 P) 2 N][Os 3 H(CO) 11 ] with Ag[PF 6 ], and the anion has been shown by an X-ray analysis to consist of an Ag I atom linking together two “Os 3 H(CO) 10 ” fragments. The electrochemistry of this complex has been investigated and it has been shown to undergo two one-electron reductions.

Allyl derivatives of [{Ti(η5-C5Me5)(μ-O)Cl)}3]: X-ray crystal structure of [{Ti(η5-C5Me5)(μ-O)(CH2CH=CHMe)}3]

Abstract Reactions of [{Ti( η 5 -C 5 Me 5 )( μ -O)Cl} 3 ] ( 1 ) with Grignard reagents, RMgCl (R = allyl (CH 2 CHCH 2 ), crotyl (CH 2 CHCHMe)), in diverse ratios and conditions allow the characterization of the allyl oxotrimers [{Ti( η 5 -C 5 Me 5 )( μ -O)} 3 R n Cl 3− n ] ( n = 3, R = allyl, 2 ; n = 1, R = allyl, 4 ; n = 2, R = allyl, 5 ; n = 3, R = crotyl, 7 ). The complexes [{Ti( η 5 -C 5 Me 5 )( μ -O)} 3 ( π -C 3 H 5 ) 3 ] ( 2 ) and [{Ti( η 5 -C 5 Me 5 )( μ -O)} 3 ( π -C 3 H 5 ) 2 Cl] ( 5 ) undergo thermal rearrangements, in a regio- and stereoselective way, to give the derivatives [{Ti( η 5 -C 5 Me 5 )( μ -O)} 3 ( μ 2 -CH 2 CH(CH 2 CHCH 2 )CH 2 }X]X = allyl ( 3 ) and X = Cl ( 6 ) respectively. These processes involve the migration of one allyl group to the β-carbon of the adjacent allyl ligand and the formation of a 2-allyl-1,3-propanediyl unit bridging two titanium atoms. The crystal structure of [{Ti( η 5 -C 5 Me 5 )( μ -O)} 3 ( σ -CH 2 CHCHMe 3 ] ( 7 ) has been studied by X-ray crystallography and can be described as three Ti( η 5 -C 5 Me 5 )( σ -crotyl) units linked through oxygen bridges forming a nearly planar Ti 3 O 3 ring.

Mercury-bridged, nitrosyl substituted, triruthenium carbonyl clusters: synthesis and X-ray crystal structure of [Ru3(NO)(CO)10]2Hg

Abstract The neutral mixed-metal cluster [Ru3(NO)(CO)10]2Hg has been prepared by the reaction of the [Ru3(NO)(CO)10], with HgCl2. An X-ray crystal structure shows that the mercury atom links two Ru3 triangular units by bridging an RuRu edge of each unit. The dihedral angle between the two Ru2Hg triangles is 27.6°. In each Ru3 triangle a nitrosyl ligand bridges the same RuRu edge as the bridging Hg atom while the ten carbonyl groups are all terminal.

Synthesis of high nuclearity cluster alkynes under mild reaction conditions; the X-ray crystal structures of [Os6(CO)17(µ-H)(µ4-η-CCEt)], [Os6(CO)17(µ4-η2-HCCEt)], and [Os6(CO)16(µ3-η-MeCCEt)]

Reaction of the labilised cluster [Os6(CO)17(NCMe)]with the terminal alkynes HCCR (R = Me, Et, or Ph) affords the isomeric alkyne substituted clusters [Os6(CO)17(µ-H)(µ4-η-CCR)][R = Me (1), Et (3), or Ph (5)] and [Os6(CO)17(µ4-η2-HCCR)][R = Me (2), Et (4), or Ph (6)], and under similar conditions the disubstituted alkynes RCCR′(R = Me or Ph; R′= Me, Ph, or Et) give [Os6(CO)16(µ3-η-RCCR′)][R = R′= Me (7); R = R′= Ph (8); R = Me, R′= Et (9)] as the major product; the structures of complexes (3), (4), and (9) have been established by X-ray diffraction studies.

Substituted osmium clusters containing labile ligands. The preparation, characterisation, and some reactions of [Os3H(OR)(CO)9(MeCN)](R = H, Me, Et, or Ph) and the isomers of [Os3H(SR)(CO)9(MeCN)](R = Me, Et, or Ph); the crystal and molecular structure of [Os3H(SPh)(CO)9(PEt3)]

The compounds [Os3H(ER)(CO)10](E = O, R = H, Me, Et, or Ph; E = S, R = Me, Et, or Ph) react with Me3NO in MeCN to produce the acetonitrile derivatives [Os3H(ER)(CO)9(MeCN)]. For ER = OR there is only one such compound formed which has the acetonitrile ligand attached to one of the bridgehead osmium atoms. These clusters react with P(OMe)3 to form two isomers of the compounds [Os3H(OR)(CO)9{P(OMe)3}], both of which have the phosphite ligands co-ordinated to one of the bridgehead osmium atoms. For the case ER = SR three isomers of the acetonitrile derivative are formed, two with the acetonitrile ligand attached to the unique osmium atom and one as in the alkoxy case. These isomers react with phosphorus donor ligands to produce isomers of the compounds [Os3H(SR)(CO)9(PR′3)], where the phosphorus donor ligand is bound to the same osmium atom as the acetonitrile in the starting material. The compounds [Os3H(OR)(CO)8-{P(OMe)3}2] were prepared from reaction of [Os3H(OR)(CO)10] with 2.2 equivalents of Me3NO followed by P(OMe)3. All the products have been characterised by i.r. and 1H n.m.r. spectroscopy and structural assignments made. The structure of [Os3H(SPh)(CO)9(PEt3)] was confirmed by X-ray analysis and shown to consist of a riangle of Os atoms with one edge bridged by both a hydride and a phenylthiolato ligand. The triethylphosphine ligand occupies a ‘pseudo’ axial site on one of the Os atoms involved in bridge bonds. The nine carbonyl groups all occupy terminal co-ordination sites.

The synthesis and characterisation of some mixed-metal carbonyl hydrides containing tungsten: the X-ray crystal structure of [(Ph3P)2N][Os3WH(CO)14]

Abstract The mixed-metal cluster anion [Os 3 W(μ-H)(μ-CO)(CO) 13 ] − has been prepared by the reaction of [Os 3 (μ-H)(CO) 11 ] − with W(CO) 3 (MeCN) 3 , and the dianion, [Os 3 W(CO) 14 ] 2− , may be obtained by subsequent deprotonation. An X-ray analysis of the monoanion shows that the metals adopt a closo -tetrahedral geometry with the W atom coordinated to four terminal and one bridging carbonyl groups. The neutral clusters [Os 3 WH 2 (CO) 14 ] and [Os 3 WH(CO) 14 ] are formed upon treatment of the monoanion with sulphuric acid and iodine, respectively.