An-Najah Staff

Interphase catalysis is gaining great importance in recent years due to the ability to combine the merits of homogeneous and heterogeneous catalysis with a remarkable reduction of drawbacks like leaching and reduced catalytic activity of the reactive center. Noyori et al. recently discovered a new ruthenium(II) complex system containing diphosphine and 1,2diamine ligands which, in the presence of a base and 2-propanol, proved to be excellent catalysts for the hydrogenation of ketones with excellent yield and selectivities under mild conditions [1]. Subsequently several chiral ruthenium(II) complexes were developed for the asymmetric hydrogenation of functionalised ketones [2]. Supporting of these complexes in polysiloxane matrices avoids leaching, whereas the activity and enantioselectivity remains constant [3]. The catalytic activity is traced back to the electronic properties of the coordination center and that the stereoselectivity is controlled by the chiral ligand [4]. Here in this report, the EXAFS investigations on the diamine(diphosphine) and diamine(etherphosphine) ruthenium(II) complexes are presented.