STRUCTURAL ASPECTS IN TRANSITION METAL COMPLEXES (Ni, Pd, Pt) WITH PHOSPHORUS-CONTAINING LIGANDS

Alexandra Cristurean, Ovidiu Moldovan, Alpar Pölnitz and Anca Silvestru

“Babes-Bolyai” University, Faculty of Chemistry & Chemical 
Engineering, 11 Arany Janos St., RO-400028 Cluj-Napoca, Romania; E-mail:  alexcristurean@yahoo.com

Metathesis reactions between group 10 transition metal halides [i.e. NiCl2·6H2O, NiCl2(PPh3), PdCl2(COD) and PtI2(COD); COD = 1,5-cyclooctadiene] and the potassium salt of some organophosphorus acids [i.e. K[(OPPh2){OP(OEt)2}N], K[(SPPh2){OP(OEt)2}N], K[(OPPh2)2N], K[(SPPh2)(O2SR)N] (R=Me, Ph, pTol)] were performed in order to investigate the coordination ability of these ligands. The new compounds were characterized by means of mass spectrometry, IR and electronic spectroscopy. The structure of the dimeric [Ni{(OPPh2)2N}2]2 (1) and the monomeric Ni[(OPPh2)2N]2·2DMFA (2) species was determined by single-crystal X-ray diffraction. In compound 1 three of the phosphorus ligands act as bimetallic triconnective units, while the fourth one is chelating a metal centre, thus resulting in different coordination geometries around the nickel atoms, i.e. square pyramidal NiO5 (for Ni1 atom) and distorted octahedral NiO6 cores (for Ni2 atom). The coordination geometry in compound 2 is octahedral, with monometallic biconnective phosphorus ligands and trans DMFA solvent molecules coordinated to the metal centre.
	
         [Ni{(OPPh2)2N}2]2			      Ni[(OPPh2)2N]2·2DMFA