An-Najah Staff

The ligands exchange of the ether-phosphine (Ph2PCH2CH2OCH3) on the diamine(ether-phosphine)ruthenium(II) with 1,3-bis(diphenylphosphino)propane as a bidentate chelate ligand successfully occurs to produce diamine[1,3-bis(diphenylphosphino)propane]ruthenium(II) complexes in a good yields under vigorous stirring for one week in an inert atmosphere using dichloromethane as solvent. Several ether-phosphine-RuC12 complexes with different types of diamine have been tested to confirm the substitution method. In order to collect more information about the system 31P{1H} NMR and 13C{1H} NMR as well as FAB- Mass spectroscopy have been investigated in parallel way to control and support the ligands exchange reaction processes.

Novel Ru(II) complex-based hybrid inorganic-organic materials immobilized via a diamine co-ligand site instead of the conventional diphosphine ligand have been prepared. The complexes were prepared by two different methods: sol-gel and surface modification techniques. The structures of the desired materials were deduced by several available physical measurements like elemental analyses, infrared, FAB-MS and 1H-, 13C- and 31P-NMR spectroscopy. Due to a lack of solubility the structures of xerogel 3 and modified 4 were studied by solid state 13C-, 29Si- and 31P-NMR spectroscopy, infrared spectroscopy and EXAFS. These materials were stable enough to serve as hydrogenation catalysts. Selective hydrogenation of functionalized carbonyls in a,b-unsaturated compounds was successfully carried out under mild conditions in a basic medium using these complexes as catalysts.

The preparation of new three trans-[RuCl2(dppb)(N–N)] with mixed diamine (N–N) and 1,4-bis-(diphenylphosphino)butane (dppb) ligands, starting from RuCl2(PPh3)3 as precursor is presented. The complexes are characterized on the basis of elemental analysis, IR, 1H, 13C and 31P{1H}NMR, FAB-MS, TG/DTA and single crystal X-ray diffraction studies. Complex (2L1) crystallizes in the monoclinic unit cells with the space group P21. The catalysts are evaluated for their Cinnamic aldehyde hydrogenation. The catalysts show excellent activity and selectivity for the unsaturated carbonyl compound under mild conditions.

The diamine (Nsingle bondN) co-ligand 2,2-dimethyl-1,3-propanediamine and 2,3-diaminophathalene react individually with [RuCl2(dppb)2(μ-dppb)] to afford complexes with kinetically stable trans-[Cl2Ru(dppb)(Nsingle bondN)] as the favoured isomer. The thermodynamically stable cis-[Cl2Ru(dppb)(Nsingle bondN)] isomer of complex 1 was formed from the trans-1 isomer. The trans to cis isomerization reaction was conducted in CHCl3 at RT and monitored by 31P{1H} NMR. The structures of the desired complexes were characterized via elemental analyses, IR and, UV–visible spectroscopy, FAB-MS and NMR. The structure of the cis-1 isomer was determined by single crystal X-ray measurements. Both the trans-1 and cis-1 isomers were shown to have a significant catalytic role in selective hydrogenation reactions under mild conditions using cinnamic aldehyde as typical model reaction.