The reaction of [ReIIICl3(t-BuNC)(PPh3)2] with aniline derivatives: Isolation of imido-Re(V) complexes and a Re(III) complex containing iminobenzoquinonate as ligand

Abstract

The rhenium(V) complexes [ReCl3(t-BuNC)(L)(PPh3)] (1–3) were isolated by the reaction of trans-[ReIIICl3(t-BuNC)(PPh3)2] (t-BuNC=tert-butyl isocyanide) with the ligands H2L (H2L=aniline (1), o-phenylenediamine (2), anthranilic acid (3)). In all these complexes the dianionic ligands L are coordinated monodentately as the imide. However, unexpectedly, with 2-aminophenol the complexes [ReVCl2(t-BuNC)(L)(PPh3)2](ReO4) (4) and the novel [ReIIICl2(t-BuNC)(ibq)(PPh3)2] (5) (ibq−=2-iminobenzoquinonate, the two-electron oxidized form of HL−) were identified as the products. These complexes were characterized by single crystal X-ray crystallography, 1H NMR spectrometry, IR and electronic spectroscopy, and cyclic voltammetry. To complement the experimental data, density functional theory (DFT) and time-dependent DFT methods were used to have a deeper understanding into the molecular parameters and infrared and electronic spectra of these complexes.