Synthesis, Crystal Structure and Catalytic Properties of Ruthenium Complexes Bearing N-heterocyclic Carbene Ligand

Two new N-heterocyclic carbene ruthenium(1) complexes [RuCl2(L1)(CO)] (1) L1=(2, 6-bis(methylimidazol-2-ylidene)pyridine) and [RuCl2(L2) (CO)] (2) L2.(2,6-bis (butylimidazol-2-ylidene)pyridine), have been synthesized and fully characterized by elemental analysis, IR spectra, H-1 NMR and C-13 NMR. The structure of complex 2 has been determined by X-ray crystallography. Complex 2 crystallizes in the Monoclinic system with C2/c space group, a=1.8148(4) nm, b=1.1292(3) nm, c=1.119 6(2) nm, beta=108.862(3) degrees, and the central Ru(II) ion is six-coordinated. The catalytic activities of complexes 1 and 2 in the Suzuki-Miyaura cross-coupling reaction have been investigated.