Structural studies on the interactions of a P2N tridentate ligand with copper(I) silver(I) and S : a dissertation presented in partial fulfilment of the degree of Master of Philosophy at Massey University
This thesis presents a study of the coordination chemistry, chemical reactivity, spectroscopy, structure and bonding of the hybrid polydentate ligand 2-(diphenylphosphino)-N-[2-(diphenylphosphino)benzylidene]benzeneamine (PNCP) with copper(I), silver(I) and sulfur. The hybrid polydentate (PNCP) ligand contains two inequivalent phosphorus (soft) and one nitrogen (hard) donor atoms, Chapter One is a brief overview of tertiary phosphines used as monodentate, bidentate, tridentate and polydentate ligands with transition metals. In Chapter Two, the preparation structure and characterisation of PNCP have been studied. Reactions of PNCP with sulphur have been investigated and a small site selectivity for one of the P atoms noted. Experiments have also included selective synthesis of the unsymmetrical mono-sulphide tertiary phosphine ligands SPNCP, PNCPS and of the di-sulfide SPNCPS ligand, as well as a study on the molecular structure of the 3-coordinate complex, [Cu(SPNCPS)]CIO₄. In Chapter Three the preparation of a series of copper(I) complexes of the general formula [Cu(PNCP)ClO₄] and [Cu(PNCP)L]ClO₄ (L- ligands containing S, N donor atoms) have been reported. The crystal structure of [Cu(PNCP)ClO₄] has been determined, and shows PNCP acts as a tridentate ligand coordinated to copper(I) via two phosphorus and one nitrogen donor atoms. The copper(I) atom has a distorted tetrahedral environment with two short Cu-P bonds and a slightly long Cu-N bond. In Chapter Four, studies on the preparation of the mononuclear complex [Ag(PNCP)ClO₄] and the dinuclear complex [Ag(PNCP)(SCN)]₂ are presented. Both complexes were characterized by a variety of physicochemical techniques. The tridentate behaviour of PNCP in the complex [Ag(PNCP)ClO₄] was established but the Ag-N bond was long and weak. In the complex [Ag(PNCP)(SCN)]₂ the Ag-N bond not exist and PNCP acts as a bidentate ligand.