Miguel A. Ciriano

Indenyl complexes of ruthenium(II). Crystal structure of [Ru(CO)(PPh3)2(η5-C9H7)]ClO4·12CH2Cl2

Abstract The compound [RuCl(PPh3)2(η5-C9H7)] (I) has been made in high yield by reaction of [RuCl2(PPh3)3] with indene and potassium hydroxide in ethanol and its reactions have been examined. Complex I reacts with appropriate nucleophiles to give the complexes [RuX(PPh3)2(η5-C9H7)] (X = H, CH3, I, SnCl3, C2Ph) and [RuCl(dppe)(η5-C9H7)]. Heating of complex I with methanol in a sealed tube leads to the elimination of the indenyl group and decarbonylation of methanol. Cationic complexes of formulae [RuL(PPh3)2(η5-C9H7)]ClO4 (L = CH3CN, 2-ClC6H4CN, CH2CHCN, 1,2-(CN)2C6H4, C2H4(CN)2, N2H4, CNBut, CO, CCHPh, and C2H4) and [Ru(L-L)PPh3(η5-C9H7)]ClO4 (L-L = 2,5-norbornadiene (nbd), tetrafluorobenzobarrelene (tfb), ethylenediamine (en), propylenediamine (pn), biimidazole (Hbim), 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen)) are obtained by treatment of complex I with the appropriate ligand and sodium perchlorate in methanol. Reaction of the vinylideneruthenium complex [Ru(η1-CCHPh) (PPh3)2(η5-C9H7)]ClO4 with oxygen gives [Ru(CO)(PPh3)2(η5-C9H7)]ClO4. The structure of [Ru(CO)(PPh3)2(η5-C9H7)]ClO4· 1 2 CH2Cl2 has been determined by X-ray diffraction. The space group is P 1 with lattice constants a 18.5513(14), b 12.9165(5), and c 9.6898(5) A, and α 80.942(5), β 104.998(7) and γ 111.130(4)°. Final R and Rw factors are 0.039 and 0.043, respectively, for the 6836 observed data (3σ(I) criterion). The metal is bonded to an indenyl group through the five-membered ring, and hexacoordination of the ruthenium atom is completed by two triphenylphosphine ligands and a carbonyl group.

Pyrazolate bridged dinuclear rhodium complexes. X-ray structure of [Rh(Pz)(CO)P(OPh)3]2

Abstract The synthesis and properties of complexes of general formulae [Rh(Pz)(CO)L] 2 (Pz = pyrazolate ion, L = phosphorus donor ligand), [Rh(Pz)(diolefin)] 2 and [Rh(Pz)(C 2 H 4 ) 2 ] 2 are reported. The crystal structure of the novel complex [Rh(Pz)(CO)P(OPh) 3 ] 2 has been determined by X-ray methods. The crystals are triclinic, space group P 1 , with Z = 2 in a unit cell of dimensions a 14.061(10), b 17.140(13), c 9.937(7) A, α 102.19(7), β 10.9.55(8), γ 75.14(8)°. The structure has been solved by Patterson and Fourier methods and refined by full-matrix least-squares to R = 0.058 for 2514 independent observed reflections. The structure consists of discrete dimeric complexes in which each rhodium is in nearly square-planar arrangement, being bonded to a carbon atom of a carbonyl group, to a phosphorus of a triphenylphosphite ligand and to two nitrogen atoms of pyrazolate ligands bridging the metal atoms. The dihedral angle between the two square planes of 86.2° gives a bent configuration to the molecule in which the carbonyls and the phosphite ligands are in a trans arrangement.

Deprotonation induced ligand-to-metal electron transfer: Synthesis of a mixed-valence Rh(-I,I) dinuclear compound and its reaction with dioxygen

Treatment of bis(2-picolyl)amine (bpa) with [{Rh(nbd)(mu-OMe)}2] leads to the unexpected and unique redox asymmetric dinuclear Rh-I,Rh+I complex [{Rh(nbd)}2(bpa-2H)] (2) with a pi-coordinating imine bound to a tetrahedral low valent rhodate(-I). Mono-oxygenation of the deprotonated bpa ligand in 2 by O2 leads to the mononuclear carboxamido complex [Rh(nbd)(bpam-H)] (3) (bpam = N-(2-picolyl)picolinamide). The second O atom of O2 ends up as a hydroxo fragment in [{Rh(nbd)(mu-OH)}2].

Rhodium wires based on binuclear acetate-bridged complexes

Abstract The synthesis, properties, structure and conductivity of a new class of one-dimensional, mixed valence Rh(I)–Rh(II) complexes { Rh 2 ( μ-O 2 CMe ) 2 ( N – N ) 2 ][ BX 4 ]} n ( N – N =bipyridine, phenanthroline; X=F, Ph) are described.

Pyrazolate thiocarbonylrhodium complexes. X-ray structure of [Rh(μ-3,5-Me2Pz)(CS)(PPh3)]2

Abstract The preparation and properties of complexes of general formulae [Rh(CS)-(HL)(PR3)2]ClO4 (HL = pyrazole (HPz), 3-methylpyrazole (H3-MePz), 3,5-dimethylpyrazole (H3,5-Me2Pz), PR3 = triphenylphosphine, tricyclohexylphosphine) and [(PR3)2(CS)Rh(μ-Pz)AuPPh3]ClO4 are reported. Complexes of the first set react with potassium hydroxide to give [Rh(μ-L)(CS)(PPh3)2 or RhPz(CS)(PR3)2 complexes. The structure of the complex [Rh(3,5-Me2Pz)(CS)(PPh3)]2 has been determined by X-ray diffraction methods. The crystals are monoclinic, space group P21/c, with Z = 4 in a unit cell of dimensions a = 12.700(11), b = 17.217(16), c = 23.041(18) A, β = 116.55(8)°. The structure has been solved by Patterson and Fourier methods and refined by full-matrix least-squares to R = 0.059 for 1978 independent reflections. The structure consists of dimeric complexes, in which each rhodium atom is in a square-planar environment being bonded to a carbon atom of a thiocarbonyl ligand, a phosphorus atom of a triphenylphosphine molecule and to two nitrogen atoms of pyrazolate ligands bridging the metal atoms. The dihedral angle of 71.1° between such two square planes leads to a bent configuration with an intramolecular rhodium-rhodium distance of 3.220 A. The thiocarbonyl and triphenylphosphine ligands are in a trans disposition.

Rhodium(III)-Catalyzed Dimerization of Aldehydes to Esters

The generous financial support from MICINN/FEDER (Project CTQ2008-03860) and G.A. (Gobierno de Aragon, Project: PM 036/2007) is gratefully recognized. V.P. thanks C.S.I.C. for an I3P postdoctoral contract.

Rhodium complexes of the binucleating ligands pyridine-2-thiolate and benzothiazole-2-thiolate. Crystal structures of [{Rh(µ-SC5H4N)(CO)2}2] and [{Rh(µ-SC5H4N)(tfbb)}2]·Me2CO (tfbb = tetrafluorobenzobarrelene)

The binuclear complexes [(Rh)µ-SC5H4N)(diolefin)}2][SC5H4N = pyridine-2thiolate, diolefin = cycle-octa-1,5-diene (cod)(1), norborna-2,5-diene (nbd)(2), or tetrafluorobenzobarrelene (tetrafluorobenzo[5,6] bicyclo[2.2.2]octa-2,5,7-triene)(tfbb)(3)] are prepared by reaction of LiSC5H4N with the appropriate complex [{Rh(µ-Cl)(diolefin)}2] and show fluxional behaviour in solution associated with the bridging ligands. The related compounds [{Rh(µ-C7H4NS2)(diolefin)}2][C7H4NS2= benzothiazole-2-thiolate, diolefin = cod(5), nbd(6), or tfbb(7)] are prepared by a similar route. Carbonylation reactions of (1) and (5) give the tetracarbonyl complexes [{Rh(µ-L)(CO)2}2][L = SC5H4N (4) or C7H4NS2(8) respectively]. Triphenylphosphine replaces carbon monoxide stepwise in compound (4) yielding the mono-(10) and di-substituted (11) complexes whilst the disubstituted complex [{Rh(µ-C7H4NS2)(CO)(PPh3)}2](9) is obtained from compound (8). Methyl iodide adds to complexes (4) and (10) affording respectively the diacetyl complexes [{Rh(µ-SC5H4N)(COMe)I(CO)}2](12) and [{Rh)(µ-SC5H4N)(COMe)l}2(CO)(PPh3)](13). The molecular structures of (3) and (4) have been determined by X-ray analyses. Crystals of (3) are triclinic, space group P, with a= 13.772(7), b= 14.184(8), c= 9.738(4)A, α= 108.99(2), β= 75.65(3), γ= 106.04(3)°, and Z= 2. Crystals of (4) are orthorhombic, space group P21212 (no, 18), with a= 14.637(6), b= 6.734(4), c= 8.852(5)A, and Z= 2. Both complexes are binuclear with two pyridine-2-thiolate groups acting as bridges. In (4) both ligands, having a head-to-tail disposition, bridge the metal centres through the N and S atoms whereas in (3) one of the pyridine-2-thiolate ligands bridges through the S atom only. The square-planar environments of the Rh atoms are completed by two tfbb ligands [(3)] or four CO groups [(4)], with metal–metal separations of 3.028(2) and 2.941 (2)A respectively.

Reactions of bis(ethylene)(tertiary phosphine)platinum complexes with phenylethynyl derivatives of titanium and silicon; crystal structure of (µ-dimethylsilanediyl)(σ-phenylethynyl)[µ-(1-σ:1–2-η-phenylethynyl)]-bis(tricyclohexylphosphine)diplatinum (Pt–Pt)

Bis(ethylene)(tertiary phosphine)platinum complexes [Pt(C2H4)2(PR3)][PR3= P(cyclo-C6H11)3, PMe2Ph, PMePh2, PPh3, or PPri2Ph] react with bis(cyclopentadienyl)bis(phenylethynyl)titanium to give compounds [Pt{η-(PhCC)2Ti(η-C5H5)2}(PR3)] in which the PhCC–Ti–CCPh group acts as a bidentate ligand to platinum. In contrast, dimethylbis(phenylethynyl)silane reacts with [Pt(C2H4)2(PR3)][PR3= P(C6H11)3, PMeBut2, or PPri2Ph] to give diplatinum complexes [Pt2(σ-CCPh){µ-(1-σ:1–2-η-CCPh)}(µ-SiMe2)(PR3)2]. A single-crystal X-ray diffraction study has established the structure of the product from [Pt(C2,H4)2{P(C6H11)3}] and [Si(CCPh)2Me2]. Crystals are monoclinic, space group P21/c(no. 14), with a= 12.44(1), b= 26.12(4), c= 15.832(8)A, β= 97.99(6)°, and Z= 4. The structure has been determined by analysis of 5 131 unique data with F > 4σ(F) collected to 2θ⩽ 50°(Mo-Kα radiation) at 200 K on a four-circle diffractometer, and refined to R 0.053 (R′0.041). The results establish a molecular structure with an SiMe2 group asymmetrically bridging a Pt–Pt separation of 2.703(1)A. Two CCPh groups are σ-bonded to one metal atom (formally PtIV) but one is also η2-co-ordinated to the other platinum (formally PtII). The P–Pt–Pt–P skeleton is non-linear with PPtPt angles of 165.2(1) and 148.0(1)°. Dimethylbis(phenylethynyl)silane reacts with [Pt(C2H4)(PPh3)2], without carbon–silicon bond cleavage, to give mono- and di-platinum η2 complexes [Pt{η-PhCCSi(C2Ph)Me2}(PPh3)2] and [Pt2{η-(PhCC)2SiMe2}(PPh3)4].

Cyclopentadienylruthenium complexes with chelating diamines and diolefins. Crystal structures of [Ru(nbd)(PPh3)(ϑ-C5H5)]ClO4 and [Ru{(η6-C6H5)Ph2PO}(η-C5H5)]ClO4. A new mode of coordination of triphenylphosphine oxide

Abstract Complexes of the general formulae [Ru(diamine)(PPh 3 )(η-C 5 H 5 )]ClO 4 and [Ru(diolefin)(PPh 3 )(η-C 5 H 5 )]ClO 4 (diamine = ethylenediamine (en), propylenediamine (pn), 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), biimidazole (H 2 bim), bibenzimidazole (H 2 bbzim) and 2-(2′-pyridylbenzimidazole) (Hpybzim); diolefin = 2,5-norbornadiene (nbd), tetrafluorobenzobarrelene (tfb)) have been made by reaction of the complex RuCl(PPh 3 ) 2 (η-C 5 H 5 ) with the diamine or diolefin in the presence of sodiuim perchlorate. A single-crystal X-ray diffraction study of [Ru(nbd)(PPh 3 )(η-C 5 H 5 )]ClO 4 has been carried out. Crystals of the complex are monoclinic, space group P 2 1 / n , with a 18.0576(5), b 14.5070(3), c 10.3186(3) A; β 103.20(6)°. The structure was solved by Patterson synthesis using 4209 observed reflections (2σ( I ) criterion) and refined to a R factor of 0.040. Reaction of RuCl(PPh 3 ) 2 (η-C 5 H 5 ) with oxygen in the presence of sodium perchlorate leads to oxidation of the coordinated triphenylphospine ligands giving the complex [Ru{(η 6 -C 6 H 5 )Ph 2 PO}η-C 5 H 5 )]ClO 4 . In order to establish the structural identity of this compound a single-crystal X-ray diffraction study has been made. Crystals of this complex are monoclinic, space group P 2 1 / c , with a 10.818(5), b 9.4480(3), c 21.0036(19) A; β 90.246(6)°. The structure was solved by Patterson synthesis using 3819 observed reflections (3σ( I ) criterion) and refined to a R factor of 0.036. The ruthenium atom is coordinated in a sandwich fashion by the cyclopentadienyl group and a phenyl ring of the triphenylphosphine oxide ligand. The synthesis of new heteronuclear ruthenium(II)-rhodium(I) complexes of formulae [(η-C 5 H 5 )(Ph 3 P)-Ru(μ-bim)RhY 2 ] x and (η-C 5 H 5 )(Ph 3 P)Ru(μ-bbzim)RhY 2 (Y = CO, Y 2 = diolefin) is also described.

Rhodium and Iridium Pyrazolato Blues

The staggered arrangement of the two dimers in 1 facilitates the formation of an almost linear chain of four metal centers that is held together by a nonsupported metal-metal bond. The intense color of the compounds and the fractional oxidation states of the metal atoms can be explained by electron delocalization along the chain. M=Rh, Ir.