111435-20-2Relevant academic research and scientific papers
Studies of the structures and bonding of gold-bridged dirhenium carbonyl cluster complexes
Adams, Richard D.,Wong, Yuen Onn,Zhang, Qiang
, p. 7540 - 7546 (2014/04/03)
The compounds Re2(CO)8(μ-AuPPh3) 2, 1, a dimer of Re(CO)4(μ-AuPPh3), and ax,ax-Re2(CO)8(PPh3)2 were obtained from UV-vis radiation-induced decarbonylation of the compound Re(CO) 5[Au(PPh3)]. Compound 1 contains two rhenium atoms bridged by two AuPPh3 groups. The complex has 32 valence electrons and is formally unsaturated by the amount of two electrons. The Re-Re bond distance in 1 is unusually short (Re-Re = 2.9070(3) A), as found by a single-crystal structural analysis. The nature of the metal-metal bonding in 1 was investigated by DFT computational analyses, which have provided evidence not only for σ-bonding but also significant complementary π-bonding directly between the two rhenium atoms. The electronic structure of Re2(CO) 8(μ-H)2, 2, was similarly analyzed and is compared with that of 1. Compound 1 is intensely colored due to low-energy, metal-based electronic transitions between the HOMO and HOMO-2 and the LUMO. Compound 1 reacts with I2 to yield Re2(CO)8(μ- AuPPh3)(μ-I), 3, and the known compound Re2(CO) 8(μ-I)2, 4, by substitution of the bridging AuPPh 3 groups with bridging iodide ligands. Compound 3 is electronically saturated, 34 valence electrons, and contains a formal Re-Re single bond: Re-Re = 3.2067(5) A. Compound 3 was also in a high yield (83%) from the reaction of Re2(CO)8(μ-H)(μ-CH=CHC4H9) with Au(PPh3)I. The Re-Re bonding in compounds 3, 4, and Re 2(CO)10 was also analyzed computationally, and this bonding was compared with their bonding in 1 and 2.
Site selectivity studies on heterobimetallic complexes: Substitution reactions of (η5-C5H5)MM′(CO)8 (M = Mo, W; M′ = Mn, Re)
Ingham, Wayne L.,Coville, Neil J.
, p. 4084 - 4090 (2008/10/08)
Synthesis of the heterobimetallic dimers (η5-C5H5)M(CO)3M′(CO) 5 (M = Mo, W; M′ = Mn, Re) has been achieved by photochemical procedures from [(η5-C5H5)M(CO)3]2 and M2(CO)10 (5-10%), by reaction of Na[(η5-C5H5)M-(CO)3] and M′(CO)5X (X = I, Br) (15-25%) and by reaction of Na[(η5-C5H5)M(CO)3] and M′(CO)5CF3SO3 (45-95%). Reaction of (η5-C5H5)MRe(CO)8 (M = Mo, W) with L (L = P(OMe)3, PMe2Ph, PMePH2, PPh3, P(CH2C6H5)3, P([p-C6H4OMe)3, t-BuNC, 2,6-Me2C6H3NC, C6H11NC, C6H5CH2NC) under Me3NO, PdO, and thermal conditions yields (η5-C5H5)MRe(CO)8-nLn (n = 1, 2) (20-90% yield). Cleavage reactions of the substituted product with Br2, performed in an NMR tube (CD3CN), revealed that replacement of CO had occurred on the Re atom. The complexes (n = 1) were obtained as the axial isomer and/or the equatorial isomer and were characterized by IR and NMR spectroscopy. Reaction of (η5-C5H5)MMn(CO)8 (M = Mo, W) with RNC (R = 2,6-Me2C6H3, t-Bu, C6H5H2, C6H11) only gave [(η5-C5H5)M(CO)3]2 and Mn2(CO)10-xRNCx (x = 1-4). Reaction with L (L = P(OMe)3, PMe3, PMe2Ph, PPh3) gave homonuclear dimers as well as (η5-C5H5)MMn(CO)7L in which substitution had occurred on Mn. The results could be interpreted in terms of the steric and electronic requirements of L as well as the steric requirements of the metal fragments. An analysis of the spectra of the new (η5-C5H5)MM′(CO)7L complexes revealed that Δ(31Pax-eq), i.e., the difference in 31P positions for axial and equatorial isomers, gave a measure of the steric size of the metal fragments.
HYDROGEN ABSTRACTION AND DIMERISATION REACTIONS OF SOME ORGANO-TRANSITION METAL FREE RADICALS
Armstead, Judith A.,Cox, David J.,Davis, Reg
, p. 213 - 220 (2007/10/02)
The 17-electron species (M=Mn, Re, x=0; M=Mn, Re; L=Ph3P, x=1, 2; M=Mn, Re; L=(o-MeC6H4O)3P, x=2; M=Mn; L=(p-ClC6H4O)3P, (PhO)3P, x=2; M=Mn; L=P(OMe)3, x=3) have been generated by one electron oxidation of the corresponding anions and show ty
