Article

Room-temperature C-C bond cleavage of an arene by a metallacarborane.

Department of Chemistry, Heriot-Watt University, Edinburgh EH14 4AS, UK.
Angewandte Chemie International Edition (Impact Factor: 11.34). 07/2010; 49(29):4943-5. DOI: 10.1002/anie.201001555
Source: PubMed
0 Bookmarks
 · 
92 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In the title compound, C4H22B20, the two {1,7-closo-C2B10H11} cages are linked across a centre of inversion, with C-C = 1.5401 (16) Å. The position of the second non-linking cage C atom was established unambiguously by geometric and crystallographic methods and there is no evidence of C/B disorder.
    Acta Crystallographica Section E Structure Reports Online 11/2014; 70(Pt 11):376-378. · 0.35 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In the title compound, C4H22B20, the two {1,2-closo-C2B10H11} cages are linked across a centre of inversion with a C—C distance of 1.5339 (11) A ˚ . By careful analysis of the structure, it is established that the non-linking cage C atom is equally disordered over cage vertices 2 and 3.
    Acta Crystallographica Section E Structure Reports Online 11/2014; 70:462. · 0.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we have carried out a DFT computational investigation on the reaction of [(dippe)]PtH]2 (1b) with benzonitrile (PhCN) leading to the products (dippe)Pt(H)(2-C6H4CN) (2) and (dippe)Pt(Ph)CN (5), which formally result from benzonitrile C-H and C-CN activation, respectively. Actually, DFT results indicate a process following a stepwise mechanism that satisfactorily explains the experimental evidence. 5 is a very stable species (19.1 kcal mol-1 below reactants and significantly more stable than compound 2). Computations clearly show that 5 does not represent an intermediate of the process eventually leading to the final products (dippe)Pt(H)CN (3) and (dippe)Pt(CN)(C6H4CN) (4). The favored path leading to product 3 originates directly from 1b, which is in equilibrium with the adduct 2. The highest energy transition state that must be overcome to give 3 is 29.1 kcal mol-1 above the reactants. Surmounting this transition structure can be considered a feasible task at the working temperature of 140 °C. Product 3 can be obtained only when a second PhCN molecule is involved in the process. PhCN behaves like a hydrogen carrier: it provides the hydrogen finally bonded to platinum in 3 and contributes to form a benzene molecule, which is released in the course of the reaction, as experimentally observed. This PhCN molecule can be considered as a catalyst of the process. Its involvement explains why, when 2 is heated in the absence of PhCN, no reaction is observed. Only in the presence of PhCN can 1b, which is in equilibrium with 2, complete the process to give 3.
    Organometallics 08/2014; 33(16):4173-4182. · 4.25 Impact Factor