Phosphoraneiminato complexes of rhenium(VII). Syntheses and crystal structures of [ReO3(NPR3)] (R = Ph, Et) and of [ReO(OSiMe3)(3)(Me3SiNPEt3)]

The phosphoraneiminato complexes [ReO3(NPR3)] with R = Ph (1) and R = Et (2 ) are made from dirhenium heptaoxide and the silylated phosphoraneimines Me 3SiNPR3. The complexes 1 and 2 as well as the red silanolate [ReO(OSiMe3)(3 )(Me3SiNPEt3)] (3), which is formed as a by-product in the synthesis of 2, are characterized crystallographically. 1 and 2 are monomeric molecules, in which the phosphoraneiminato ligands NPR3- realize short ReN bonds of 179. 3 pm (1) and 178.6 pm (2), respectively, with large ReNP bond angles of 162 .0 degrees (1) and 160.6 degrees (2), respectively. In the rhenium(V) compl ex 3 the oxoligand occupies the apical position of the tetragonal pyramidal coordination of the rhenium atom, while the oxygen atoms of the Me3SiO- gr oups take the basic positions along with the nitrogen atom of the phosphane imine molecule.