Triple-decker complex CpCo(μ-C3B2Me5)Rh(C2H4)2: Synthesis, structure and bonding
摘要:
The reaction of the thallium derivative [CpCo(mu-C3B2Me5)]Tl with [Rh(C2H4)(2)Cl](2) affords the mu-diborolyl bis(ethylene) triple-decker complex CpCo(mu-C3B2Me5) Rh(C2H4)(2) (4). Structure of 4 was determined by X-ray diffraction. According to DFT calculations, the ethylene dissociation energies for the triple-decker complexes CpCo(mu-C3B2R5) Rh(C2H4)(2) (R = H, Me) are ca. 6 kcal mol(-1) lower than for cyclopentadienyl analogs (C5R5) Rh(C2H4)(2). Energy decomposition analysis revealed that the bonding of anions [CpCo (C3B2R5)] - with [Rh(C2H4)(2)](+) is also weaker than that of [C5R5] -; the attractive interactions in both cases are 60-63% electrostatic and 37-40% covalent. The electrostatic potentials at the Rh nuclei suggest that the donor ability of the anions increases in the following order: Cp < [CpCo(C3B2H5)] <= [CpCo(C3B2Me5)] < Cp*. (C) 2014 Elsevier B.V. All rights reserved.