Reactivity of Transition Metal–Phosphorus Triple Bonds towards Triply Bonded [{CpMo(CO)₂}₂]: Formation of Heteronuclear Cluster Compounds

Abstract

Thermolysis of [Cp*P{W(CO)5}2] (1) in the presence of [{CpMo(CO)2}2] leads to the novel complexes [{(CO)2Cp*W}{CpMo(CO)2}(micro,eta2:eta1:eta1-P2{W(CO)5}2)] (6; Cp=eta5-C5H5, Cp*=eta5-C5Me5), [{(micro-O)(CpMoWCp*)W(CO)4}{micro3-PW(CO)5}2] (7), [{CpMo(CO)2}2{Cp*W(CO)2}{micro3-PW(CO)5}] (8) and [{CpMo(CO)2}2{Cp*W(CO)2}(micro3-P)] (9). The structural framework of the main products 8 and 9 can be described as a tetrahedral Mo2WP unit that is formed by a cyclisation reaction of [{CpMo(CO)2}2] with an [Cp*(CO)2W[triple chemical bond]P-->W(CO)5] intermediate containing a W--P triple bond and subsequent metal-metal and metal-phosphorus bond formation. Photolysis of 1 in the presence of [{CpMo(CO)2}2] gives 8, 9 and phosphinidene complex [(micro3-PW(CO)5){CpMo(CO)2W(CO)5}] (10), in which the P atom is in a nearly trigonal-planar coordination environment formed by one {CpMo(CO)2} and two {W(CO)5} units. Comprehensive structural and spectroscopic data are given for the products. The reaction pathways are discussed for both activation procedures, and DFT calculations reveal the structures with minimum energy along the stepwise Cp* migration process under formation of the intermediate [Cp*(CO)2W[triple chemical bond]P-->W(CO)5].

Stepwise Expansion of a Cp* Ring at Pentelidene Complexes and Stereoselective Formation of Triphosphines

“…In addition, the found formation process of triphosphines is completely different from those of former reports on hydrogenation of halogen-containing triphosphines, methanolysis of silylated triphosphines, and the catalytic dehydrocoupling of phosphines. [25] This reaction pattern of the pentelidene complexes 1 is in strong contrast to the Cp* migration process of 1 usually found to form the triply bonded intermediates [Cp*(CO) 2 WE!W(CO) 5 ], [26] which can be trapped by alkynes, [27] phosphaalkynes, [28] and compounds with metalmetal multiple bonds [29] to form transition-metal cages containing Group 15 elements. Moreover, under photolytic conditions, a radical Cp* displacement is found.…”

The First Late‐Transition‐Metal Cyclopentadienyl Chelate Complexes with Silylphosphane or Secondary Phosphane Tethers

“…The anionic ligand is trapped with iron(II) chloride with formation of the respective ferrocene derivative. [35] One molybdenum example has been published by Scheer et al [36] In many cases, these complexes were prepared by reaction of the dianionic ligand system with a suitable complexation reagent.While the reaction of a lithiated primary or secondary phosphane with a fulvene affords a ligand system with one carbon atom between the cyclopentadienyl and the phosphane moieties, [15,30,37] the corresponding reactions with spiro[2.4]hepta-4,6-dienes give rise to ligand systems with an ethylene bridge between them. Deprotonation, reaction with spiro[2.4]hepta-4,6diene, followed by treatment with nickel dihalide complexes www.eurjic.org FULL PAPER 1989; [9] 2 bears an internal amine ligand and was prepared by Hadjiliadis et al in 1998; [10] 3 represents a cyclopentadienylalkylphosphane nickel chelate and was prepared in our group in 2007; [11] 4 is a cationic chelate with sulfur coordination, which was prepared by Rauchfuss et al in 1985, [12] and alkene complex 5 was prepared by Okuda et al.…”

The Complexed Triphosphaallyl Radical, Cation, and Anion Family

“…This reaction proceeds primarily under thermolytic conditions, however, photolysis of 1 leads, additionally, to the elimination of a Cp*C moiety and the formation of the radical intermediate H. [24] The electronic structure of H was recently calculated by using DFT methods. [21] We now find that this intermediate acts as a phosphorus-radical-transfer reagent and is responsible for the reaction of 1 with diphosphenes to afford an unprecedented complex of type E.…”

“…[18] We have shown that the phosphinidene complex [Cp*P{W(CO) 5 } 2 ] (1) [19] is an excellent starting material for the in situ generation of intermediate G, [20] which contains a tungsten-phosphorus triple bond (Scheme 1). The intermediate can be trapped by organometallic compounds that contain multiple metal-metal bonds, [21] alkynes, [22] and phosphaalkynes to give novel clusters, metal-containing heterocycles, or cage compounds. In the latter reaction, an unusual opening of the Cp* ligand is observed to form an unprecedented 1,2-diphosphacyclooctatetraene ligand.…”