Jean-Jacques Bonnet

Synthesis and evaluation of the catalytic properties of homo- and hetero-bimetallic complexes containing bridging diphenylphosphido ligands

The bimetallic complex [(CO)3Ru(μ-PPh2)2Ru(CO)3] (1) has been prepared in 42% yield by the reaction of [Ru3(CO)12] with t

Synthesis, catalytic activity and the molecular structure of (μ3-CCH3)Co3(CO)7-μ-(Ph2PCH2PPh2)

Abstract Reaction of (μ3-CCH3)CO3(CO)9 (I) with dppm (dppm = bis-(diphenylphosphino)methane) affords the cluster (μ3-CCH3)Co3(CO)7-dppm (II). The crystal and molecular structure of II have been determined at −160°C. The dppm ligand bridges one of the three metal—metal edges in the equatorial plane to give a five-membered ring, which adopts an envelope conformation. Cluster II functions as a catalyst for the hydroformylation of 1-pentene (80 bar of H2/CO (1/1); 110°C). The results indicate that the dppm bridging ligand stabilizes and activates the cluster for catalysis, and open the way to the synthesis of chiral clusters.

Crystal and molecular structure and magnetic properties of a tetrameric copper(II) complex with 3-hydroxy-5-hydroxymethyl-4-(4′-hydroxy-3′-methyl-4′-phenyl-2′-azabut-1′-en-1′-yl)-2-methylpyridine (H2L) : [Cu4L4]·8MeOH, a complex with a ferromagnetic ground state

The crystal and molecular structure of the title compound has been determined from single-crystal X-ray diffraction data and refined to a final R value of 0.053 using 2 514 independent reflections. The compound belongs to the space group P42/n of the tetragonal system with two tetrameric molecules in a unit cell of dimensions a= 17.226(4) and c= 14.667(3)A. The tetrameric unit with a Cu4O4 core is of S4 symmetry. Copper–copper distances are 3.481(1)(two), 3.259(1)A(four) and Cu–O distances are 1.945(4)(four), 2.734(4)(four), and 1.977(4)A(four). The co-ordination about the copper atom is distorted square pyramidal with copper bonded to phenolic oxygen O(2), imine nitrogen N(1), and three alkoxo-oxygen atoms O(1). The complex crystallizes with 16 methanol molecules per unit cell. It easily loses in air the methanol molecules of crystallization giving an amorphous powder. The magnetism of the crystallized complex can be explained on the basis of the isotropic Heisenberg–Dirac–van Vleck model. Taking into account intercluster interactions, the fitting procedure yielded the values g= 2.12, J13= 17.1 cm–1, θ=–1.1 K. These parameters indicate a predominance of ferromagnetic interactions with a quintet ground state (S′= 2). The magnetic behaviour of the amorphous powder is quite different and shows weak antiferromagnetic interactions.

Complexes dinucleaires pontes des metaux d8: VII. Reactions d'addition oxydante d'halogenures d'alkyle et d'acycle aux complexes μ-halogenes du rhodium(i) [RhX(CO)(PR3)]2. Structure cristalline de [RhCl(CO)(PMe2Ph)(Me)(Br)]2

Abstract The halogen bridged binuclear complexes of rhodium(I) [RhCl(CO)(PR 3 )] 2 undergo oxidative addition with methyl halides to yield the complexes [RhCl(CO)(PR 3 )(Me)(X)] 2 (X = Cl, Br). The crystal and molecular structures of [RhCl(CO)(PMe 2 Ph)(Me)(Br)] 2 have been determined from a single crystal by use of X-ray crystallographic methods. The space group is Pca 2 1 or Pacm with a 19.501(5), b 10.381(4), c 13.641(5) e Z = 4. Parameters of 30 nonhydrogen atoms in the space group Pca 2 1 were refined by the full-matrix least squares technique to a conventional R factor of 0.073. In a binuclear unit, each rhodium atom is in an octahedral environment being bonded to a carbonyl group, a methyl group and a tertiary phosphine ligand and three halogen atoms for which, due to a disorder phenomenon, the diffusion factors have been determined as the average between those of chlorine and bromine atoms. In solution the cis -migration of the methyl groups occurs, leading to the acetyl complexes. In the case of CH 3 I, it is shown that an equilibrium is present in solution: [RhCl(CO)(PR 3 (Me)(I)] 2 ⇌ [RhCl(COMe)(PR 3 )(I)(solvant)] 2 ] Carbonylation reactions shift this equilibrium to give the complexes [RhCl(CO)(COMe)(PR 3 (I)] 2 . Such complexes are readily prepared by direct oxidative addition of acyl halides to the compounds [RhCl(CO)(PR 3 )] 2 .

Interstack Interactions in Potassium Bis(1,2-Cyclobutenedione 3,4-dithiolato) Palladate. Crystal Structure

Abstract Potassium bis(1,2-cyclobutenedione 3,4-dithiolato) palladate (Pd(dithiosquarato)2K2) crystallizes in the monolinic system, space group P21/c, a = 8.046(2), b = 15.235(4), c = 6.289(1). The dithiosquarate entities are stacked in parallel columns separated by potassium cations and water molecules. π-interactions within a stack are evidenced by the short stacking distance (3.51 A). Further interstack interactions involve close S…O or O…O interstack contacts. (∼3.5 A). As a result, the structural arrangement is nearly two-dimensional. Conductivity measurements carried out on pressed pellets show a semi-conductive behavior (σ = 2 × 10−5 Ω−1 cm1).

Reactivity of trinuclear ruthenium complexes involving bis(diphenylphosphino)methane (dppm) as a bridging ligand: facile declusterification of [Ru3(CO)8(µ-dppm-PP′)2] in the presence of iodine and the crystal structure of [Ru2(µ-I)2(CO)4(µ-dppm-PP′)]

[Ru3(CO)8(µ-dppm-PP′)2] reacts with iodine in toluene to yield a mixture of [Ru2(µ-I)2(CO)4(µ-dppm-PP′)] and [Rul2(CO)2(dppm-PP′)]. Both complexes have been characterized spectroscopically. The structure of the binuclear species [Ru2(µ-l)2(CO)4(µ-dppm-PP′)] has been determined using X-ray analysis. The two metal centres are connected by a bridging dppm ligand and two bridging iodide atoms. The metal–metal bonding distance is 2.7074(6)A.

High-yield syntheses of sulphido triruthenium carbonyl cluster complexes containing bis(diphenylphosphino)methane

Reaction of thiophenol with [Ru3(CO)10(µ-dppm)][dppm = bis(diphenylphosphino)methane] in toluene at 85 °C leads to the thiolato hydrido cluster complex [ Ru3(µ-H)(µ-SPh)(CO)8(µ-dppm)] in 75% yield. Prolonged heating under the same conditions gives the sulphido complex [ Ru3(µ3-S)(CO)8(µ-dppm)] in 95% yield. This complex reacts with hydrogen to yield the hydrido species [Ru3(µ-H)2(µ3-S)(CO)7(µ-dppm)]. The above sequence of reactions was repeated with [Ru3(CO)8(µ-dppm)2], leading directly to [Ru3(µ3-S)(CO)6(µ-dppm)2] in 80% yield. Subsequent formation of [Ru3(µ-H)2(µ3-S)(CO)5(µ-dppm)2] is achieved in the presence of hydrogen. These reactions show that co-ordination of thiophenol to dppm-substituted triruthenium clusters inhibits the oxidative cleavage of P–C bonds, while subsequent S–C bond cleavage gives sulphido–triruthenium complexes in high yield. The X-ray structure of the intermediate complex [Ru3(µ-H)(µ-SPh)(CO)8(µ-dppm)] has been determined: triclinic, space group P, a= 12.361(l), b= 15.315(2), c= 11.591(2)A, α= 92.04(l), β= 105.62(l), γ= 112.70(1)°, and Z= 2. The intensities of 5 629 reflections (2 3σ(Fo2). Final R′ and R values were 0.032 and 0.041, respectively. The structure shows that the dppm ligand and the thiolato group span different edges of the cluster with the hydrido ligand bridging the same edge as the thiolato group. The Ru–Ru bond distances are 2.867(1), 2.837(1), and 2.835(1)A.

Intermolecular association of cyanide substituted triruthenium carbonyl cluster anions: synthesis and crystal structure of [ppn]2[Ru6(CN)2(CO)20][ppn = bis(triphenylphosphine)iminium cation]

[ppn][CN][ppn = bis(triphenylphosphine)iminium cation] reacts with Ru3(CO)12 to give a cyano triruthenium carbonyl cluster anion which subsequently loses CO and dimerizes as the hexanuclear dianion [Ru6(µ-CN)2(CO)20]2–; an X-ray structural analysis shows that the structure involves two parallel ruthenium triangles linked by two axial CN bridges.

Complexes dinucleaires pontes des metaux d8

Abstract In the course of the study of the reactivity of the dinuclear complexes [RhCl(CO)(C2H2)]2 and [RhSR(CO)2]2 towards nucleophiles, two series of dinuclear pentacoordinated rhodium(I) complexes, [RhCl(CO)(C2H4)(amine)]2 and [RhSR(CO)2PR3]2, have been isolated.