Transition metal complexes of antimony centered ligands based upon acenaphthyl scaffolds. Coordination non-innocent or not?

The synthesis and structures of the di- and triorgano antimony compounds (6-Ph2P-Ace-5-)2SbCl (1) and (6-Ph2P-Ace-5-)3Sb (2) are presented along with their use as coordination non-innocent ligands for transition metals, leading to the complexes Cl(6-Ph2P-Ace-5-)2SbCuCl (3), Cl2(6-Ph2P-Ace-5-)2SbPdCl (4), Cl2(6-Ph2P-Ace-5-)2SbPtCl (5) and Cl(6-Ph2P-Ace-5-)3SbRhCl (6). The electronic structures of 1-6 were investigated by DFT computations using a set of topological and surface-based real-space bonding indicators derived from the Atoms-In-Molecules (AIM), Non-Covalent interactions Index (NCI), and Electron Localizability Indicator (ELI-D) methods, unravelling a dative Sb-Cu bond character in 3 and polar-covalent Sb-Pd/Pt/Rh interactions in 4-6.