María J. Rosales-Hoz

Rupture of a PS bond in a disulfurimidophosphinate ligand. The X-ray crystal structures of [(μ2-H)Ru3(μ3-S){μ2-S,S,P′-(SPPh2)(PPh2)N}(CO)8] and [(μ2-H)Ru3{μ2-S,S,P′-(SPPh2)(PPh2)N}(CO)9]

Abstract The reaction of [Ru3(CO)12] with (SPR2)2NH produced, initially, [(μ2-H)Ru3(μ3-S){μ2-S,S,P′-(SPPh2)(PPh2)N}(CO)8 and [(μ2-H)Ru3{μ2-S,S,P′-(SPPh2)(PPh2)N}(CO)9] in which for both compounds one of the Pue605S bonds of the ligand has been broken while the other Pue605S group is bonded through the sulfur atom to two ruthenium atoms. In one of the compounds described, the lost sulfur atom moves to a triply bridging position bonded to the triangle of metal atoms. In the second compound, the sulfur atom is lost.

The reaction of [Ru3(CO)12] with bis(diphenylphosphino)amine. The crystal and molecular structure of [Ru3(CO)10(dppa)] and [Ru3(CO)8(dppa)2]

Abstract The reaction of [Ru 3 (CO) 12 ] with bis(diphenylphosphino)amine (dppa) in the presence of sodium benzophenone leads to [Ru 3 (CO) 10 (dppa)] in quantitative yield, while the same reaction carried out in refluxing toluene also produces the disubstituted product [Ru 3 (CO) 8 (dppa) 2 ]. Both products were characterized spectroscopically and by X-ray crystallography. The five-membered rings, formed by the coordinated ligand and the two metal atoms, show distorted envelope conformations. There are significant differences in the Pue5f8N bond lengths of each dppa ligand in the disubstituted cluster while they are totally symmetric in the monosubstituted derivative.

Reactivity of [Ru3(μ-H)(μ-Me2pz)(CO)10] with 2,4-hexadiyne. Characterization of the first tetranuclear ynenyl complex

Abstract The tetranuclear ynenyl complex [Ru4(μ-η2-Me2pz)(μ4-η4-MeCHue605Cue5f8Cue606CMe)(μ-CO)(CO)10] (Me2pz=3,5-dimethylpyrazolate) has been prepared by reaction of [Ru3(μ-H)(μ-η2-Me2pz)(CO)10] with 2,4-hexadiyne and has been characterized by X-ray diffraction methods. It consists of an unusual broken-wing butterfly (spiked triangle) tetraruthenium framework (64-electron) with all the metal atoms bridged by a hex-2-yn-4-en-4-yl ligand (7-electron donor). This type of coordination is unprecedented for ynenyl ligands.

Reactivity of [Ru3(μ3-NPh)(μ3-CO)(CO)9] towards Activated Alkynes and Diynes − Isolation of a Trinuclear Intermediate During the Formation of Bi- and Tetranuclear Products

Treatment of the trinuclear imido-bridged cluster compound [Ru3(μ3-NPh)(μ3-CO)(CO)9] (1) with activated alkynes (methyl propynoate and methyl phenylpropynoate) and diynes (diphenylbutadiyne, 2,4-hexadiyne, 1,6-diphenyloxy-2,4-hexadiyne, and 1-trimethylsilyl-1,4-pentadiyne) in hexanes at reflux temperature leads to separable mixtures of the tetranuclear and binuclear derivatives [Ru4(μ4-NPh)(μ4,η2-RC≡CR′)(μ-CO)2(CO)9] and [Ru2{μ,η3-RC=CR′C(O)NPh}(CO)6], respectively. While the former complexes feature a phenylimido ligand in a rather rare μ4-coordination mode, the binuclear compounds contain acrylamido ligands that result from the coupling of a CO ligand and the original phenylimido ligand of 1 with the incoming alkyne or diyne. Surprisingly, all the products derived from diynes contain a pendant (non-coordinated) alkyne functionality. The isolation of the trinuclear derivative [Ru3(μ3-NPh)(μ3,η2-PhC≡CC≡CPh)(CO)9] (9) in the reaction of 1 with diphenylbutadiyne and the fact that its thermolysis leads to a mixture of [Ru4(μ4-NPh)(μ4,η2-PhC≡CC≡CPh)(μ-CO)2(CO)9] and [Ru2{μ,η3-C(C≡CPh)=C(Ph)C(O)NPh}(CO)6] support the proposal that trinuclear species containing coordinated alkyne or diyne ligands, similar to 9, are intermediates in the synthesis of all the bi- and tetranuclear products. Only one of the two possible regioisomers of each product (that might have arisen from the asymmetry of the alkyne or diyne reagents used) is formed. The origin of this regioselectivity is also discussed.

SI2ME4-BRIDGED ZIRCONOCENE DICHLORIDES : CRYSTAL AND MOLECULAR STRUCTURE OF MESO-SI2ME4(3-SIME3-C9H5)2ZRCL2

Abstract A series of complexes Si 2 Me 4 L 2 ZrCl 2 (L=Ind ( 1b ), 2-Me–Ind ( 2b ), 3-SiMe 3 –Ind ( 3b ) and Ind–H 4 ( 4 )) was prepared. The syntheses of 1b , 3b and 4 gave predominantly the meso -isomers, whereas a 1:1 meso : rac mixture was obtained for 2b . X-ray analysis of meso - 3b revealed large steric hindrance on the metal center (Cp°–Zr–Cp° is 134.6°). The 1:1 mixture of meso - 2b and rac - 2b (activated with MAO) produced a 2.2:1 mixture of elastic atactic and isotactic polypropylene with low activity.

Pyrolysis of [Ru3(CO)10(dppe)]: activation of CH and PPh bonds.: The crystal structure and dynamical behavior of [Ru4(CO)9(μ-CO){μ4–η2-PCH2CH2P(C6H5)2}(μ4–η4-C6H4)]

The pyrolysis reaction of [Ru 3 (CO) 10 (dppe)], compound 1 , in toluene yields as the main product [Ru 4 (CO) 9 (μ-CO){μ 4 –η 2 -PCH 2 CH 2 P(C 6 H 5 ) 2 }(μ 4 –η 4 -C 6 H 4 )], compound 2 . The X-ray structure of 2 shows a benzyne group coordinated to a square of ruthenium atoms and a μ 4 –η 2 -PCH 2 CH 2 PPh 2 fragment. Variable-temperature NMR experiments showed three independent dynamic processes: a rotation of the benzyne group, CO migration and a twisting movement of the CH 2 ue5f8CH 2 fragment. The thermolysis of [Ru 3 (CO) 10 (dfppe)], compound 3 , (dfppe=1,2-bis(dipentafluorophenylphosphino)ethane, carried out under the same conditions, showed 3 to be stable.

The reaction of [H4Ru4(CO)12] with 1-penten-3-yne: dimerization and trimerization through the triple bonds

Abstract The clusters [Ru4(μ-CO)(CO)10(μ4-η1:η2:η1:η2-C5H6)2] (1), [Ru4(CO)8(μ4-η4:η1:η1:η1:η3-C10H12)(μ3-η3:η2:η1-C5H6)] (2) and [Ru4(CO)10(μ4-η4:η1:η1:η3:η1-C15H16)] (3) have been prepared from the reaction of [H4Ru4(CO)12] with 1-penten-3-yne. This reaction is observed to proceed with dimerization and trimerization through the triple bonds. The products were characterized spectroscopically by 1H- and 13C-NMR. X-ray crystal structures of compounds 1 and 2 are also described.

Reactivity of Alkyne-Substituted Transition Metal Clusters: An Overview

In this work we present a summary of reactivity studies of alkyne substituted transition metal clusters towards different nucleophilic and electrophilic reagents. This work is not comprehensive but includes some of the most representative types of reactions of this type of compounds.

Two types of tetrasubstitution in [H4Ru4(CO)12]: spectroscopic characterization and crystal structure determination of [H4Ru4(CO)8(PMe2Ph)4] and [H2Ru4(CO)9(PMe2Ph)4]

Abstract Two tetrasubstituted tetranuclear ruthenium clusters containing dimethylphenylphosphine [H4Ru4(CO)8(PMe2Ph)4] and [H2Ru4(CO)9(PMe2Ph)4] were prepared and characterized spectroscopically as well as by X-ray crystallography. Both compounds show a structure based on the usual 60-electron tetrahedral framework with each ruthenium atom being bonded to one phosphine ligand. In the case of the nonacarbonyl derivative, one of the ruthenium atoms has one terminal carbonyl group and is also bonded to two semibridging carbonyl groups; two other metal–metal bonds are bridged by the hydride groups. In the case of the octacarbonyl compound all the ruthenium atoms are bonded to two terminal carbonyls and to two bridging hydrides. NMR spectroscopical information of [H4Ru4(CO)8(PMe2Ph)4] suggests the presence of two isomers in solution which we propose to have D2d and Cs symmetries. The observation of the NMR properties gives some observations about conditions that favour coupling between substituents in different ruthenium atoms.