Change of the coordination type for the phospholyl ligand under nucleophilic attack of H2O on phosphorus atom in 2,5-diphenylphosphacymantrene promoted by aliphatic amines
作者:Allan G. Ginzburg、Vasily V. Bashilov、Fedor M. Dolgushin、Alexander F. Smol’yakov、Pavel V. Petrovskii、Viatcheslav I. Sokolov
DOI:10.1016/j.ica.2011.01.094
日期:2011.5
eta(5)-2,5-Diphenylphosphacymantrene (1) in benzene or CH2Cl2 solution does not react with amines. However, with amines NHEt2, NEt3, NEt(i-Pr)(2) in excess and in the presence of small amounts of water 1 reacts to form anionic complexes [(CO)(3)Mn(eta(4)-Ph2H2C4P(=O)H] A(+), where cation A = H2NEt2+ (2a), HNEt3+ (2b), HN(Et)(Pr-i)(2)(+) (2c). Probably, first an unstable intermediate with P-OH bond is formed as a result of the attack by the activated H2O molecule at the P atom. Afterwards, the rapid rearrangement occurs with migration of H from O to P which leads to the ligand 2,5-diphenyl-1-H-phosphol-1-oxide, Ph2H2C4P(=O)H. Salts 2a-c have been characterized by H-1, P-31, C-13 NMR- and IR-spectra and the structures of 2a and 2c established by single crystal X-ray diffraction analyses. The phosphoryl ligand in anions 2a and 2c has the "envelope" conformation and is eta(4)-coordinated with Mn(CO)(3). The phosphorus atom is not involved in the coordination with Mn because the Mn-P distances (2.7670(4) and 2.7732(8) angstrom) are greater than the sum of covalent radii of P and Mn. (C) 2011 Elsevier B.V. All rights reserved.