synthesis and structural analysis of mono-oxo Re(V) complexes with phosino-carboxylato ligands

摘要

[~nBu_4N][Re(O)Cl_4] or [Re(O)Cl_2(OEt)(PPh_3)_2] react with PCOOH (2-(diphenylphosphanyl)benzoic acid) in different stoichiometries leading to the mono-substituted complexes [~nBu_4N][Re(O)Cl_3(PCOO)] (2) and [Re(O)Cl_2(PCOO)(PPh_3)] (5), respectively. In CH_2Cl_2-MeOH, 2 rearranges partially into the neutral [Re(O)Cl_2(PCOO)(MeOH)] (3). The mixed [Re(O)(OCH_2CH_2O)(PCOO)(MeOH)] (4) is obtained by reacting [~nBu_4N][Re(O)Cl_4], ehtylene glycol and PCOOH. The [PCOO]~- ligand is bidentate and the coordination geometry around rhenium is distorted octahedral, as shown by the X-ray structural analysis of 2 and 3. In these complexes the phosphorus and the oxygen atoms of the phosphino-carboxylato ligand occupy an equatorial and an axial position, respectively.