Bonding in PdCl(NO) and Related Nitrosylmetal Species of the Enemark–Feltham {MNO}10Type

Abstract

AbstractThe crystal‐structure analysis of the coordination polymer PdCl(NO) (1) by Evers et al. shows a two‐dimensional PdCl network of four‐coordinate Pd atoms and triply bridging chlorido ligands. The fourth ligand at Pd is a terminally bonded nitrosyl ligand in a bent PdNO function (Pd−N−O=129°). In terms of the Enemark–Feltham notation,1is an {MNO}10compound which leaves a choice regarding the assignment of the ten electrons as d10‐Pd0Cl−(NO+), d9‐PdICl−(NO) or d8‐PdIICl−(NO−) with 0, 1 and 2 electrons allocated at the nitrosyl ligand, respectively. The quantum‐chemical treatment by DFT methods and subsequent determination of the oxidation states (OSs) by Salvador's Effective‐OS (EOS) method shows highly covalent Pd−NO bonds which narrowly end up on the Pd0Cl−(NO+) side in the course of the OS assignment's heterolytic bond‐cleavage procedure. Related halonitrosyls are included to examine the obvious suitability of both linear and bent MNO units as ‘ground‐state canditates’ of {MNO}10systems. Local‐mode analysis confirmed the recently formulated weakening of both the metal−nitrosyl and the N−O bond on bending a linear MNO function.