Journal of the Korean Chemical Society 2013, Vol. 57, No. 6 Printed in the Republic of Korea http://dx.doi.org/10.5012/jkcs.2013.57.6.726 -726- Multi-Nuclear NMR Investigation of Nickel(II), Palladium(II), Platinum(II) and Ruthenium(II) Complexes of an Asymmetrical Ditertiary Phosphine Joe Gerald Jesu Raj * , Devendra Deo Pathak † , and Pramesh N. Kapoor ‡ Institut National de la Recherche Scientifique (INRS), Centre for Energy, Materials and Telecommunications (EMT), 1650, Boulevard Lionel-Boulet, Varennes, J3X 1S2, Quebec, Canada. * E-mail: raj@emt.inrs.ca † Department of Applied Chemistry, Indian School of Mines, Dhanbad 826 004 India ‡ Department of Chemistry, University of Delhi, Delhi 110 007, India (Received September 27, 2013; Accepted October 24, 2013) ABSTRACT. Complexes synthesized by reacting alkyl and aryl phosphines with different transition metals are of great inter- est due to their catalytic properties. Many of the phosphine complexes are soluble in polar solvents as a result they find appli- cations in homogeneous catalysis. In our present work we report, four transition metal complexes of Ni(II), Pd(II), Pt(II) and Ru(II) with an asymmetrical ditertiaryphosphine ligand. The synthesized ligand bears a less electronegative substituent such as methyl group on the aromatic nucleus hence makes it a strong σ-donor to form stable complexes and thus could effectively used in catalytic reactions. The complexes have been completely characterized by elemental analyses, FTIR, 1 HNMR, 31 PNMR and FAB Mass Spectrometry methods. Based on the spectroscopic evidences it has been confirmed that Ni(II), Pd(II) and Pt(II) complexes with the ditertiaryphosphine ligand showed cis whereas the Ru(II) complex showed trans geometry in their molec- ular structure. Key words: Ditertiaryphosphines, Catalysis, Configuration, Isomerism, Chirality INTRODUCTION Organophosphines are high use in applications such as ligands for homogeneous catalysis, phase transfer catalysis, intermediate syntheses, vulcanizing agents, metal extraction reagents and fire retardants. Metal complexes of phos- phines have been widely used in clinical field including the use of a Au(I)PEt 3 complex as heart-imaging agents, anti-arthritic and anti-cancer drugs. 1 Metal based drugs have attracted major attention in recent times due their potential use in the anti-cancer activity. 2-4 Data on cyto- toxicity and anticancer activity are surveyed in detail with particular emphasis on diphosphines and their copper, sil- ver and gold complexes. Much phosphine chemistry of relevance to biology has yet to be explored. Metal complexes of ditertiary phosphines have also found applications in homogeneous and heterogeneous catalysis. Ditertiary phos- phine complexes of nickel, palladium, and platinum exhibit various modes of coordination in square planar configu- ration. Recently palladium complexes tris(2-methoxyphe- nyl)phosphine complexes have been successfully used in the telomerization of 1,3-butadiene which is an important step in the 1-octene process. 5 Palladium-phosphine com- plexes have also found applications in cross-coupling of aryl halides with arylboronic acids and is one of the most valuable synthetic methods for the synthesis of biphenyl derivatives, 6 potential drug candidates, 7 coordinating ligands, 8 and functional materials 9 and also in homogeneous cata- lysts. 10 Supported palladium-phosphine complex catalyzed Suzuki-Miyaura cross-coupling reactions have also been reported. 11 Phosphine sulfonate complexes of nickel have found potential application in the olefin polymerization reactions. 12 Homogeneous ruthenium-phosphine complex has been successfully employed in the hydrogenation of carbon dioxide to form ethanol. 13 Phosphine complexes of Ni, Pd and Pt have been used in the catalytic hydrogenol- ysis of biphenylene under H 2 at moderate temperature. 14 In view of the immense applications of metal complexes of phosphines R.N. Kapoor 15 et al., synthesized and char- acterized Ni(II), Pd(II), Pt(II) complexes of a diphos ligand, 1-diphenylphosphino-2-bis(m-tolyl)phosphineethane. 15 Their work describes the characterization of these complexes only by methods such as magnetic susceptibilies, elec- tronic, electrical conductance and FTIR. 1 N HMR spec- troscopy was not discussed in detail. Also they have not reported the Ru(II) complex of the 1-diphenylphosphino- 2-bis(m-tolyl)phosphine ethane. In our present work, we synthesized and completely characterized Ni(II), Pd(II), Pt(II) and Ru(II) complexes of 1-diphenylphosphino-2-bis(m- tolyl)phosphinoethane. This unsymmetrical ligand has the ability to tune the electronic properties of complex and hence can find potential applications in polymerization or