SYNTHESIS, CHARACTERIZATION AND CRYSTAL-STRUCTURE OF [RU(TPPZ)(4,4'-(CH3)(2)BPY)CL](PF6), (TPPZ=2,3,5,6-TETRAKIS(2-PYRIDYL)PYRAZINE)

The synthesis and characterization of the complex [Ru(tppz)(4,4'-(CH3) (2)bpy) Cl](+), where tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine, is r eported. The ion was obtained in a one pot synthesis by reduction of R u(4,4'-(CH3)(2)bpy) Cl-4 with triethylamine in the presence of tppz, a nd isolated as the hexafluorophosphate salt. The structure of [Ru(tppz )(4,4'-(CH3)(2)bpy)Cl](PF6), 1, was established by X-ray diffraction. The ruthenium atom is in a highly distorted octahedral environment wit h the 4,4'-(CH3)(2)bpy nitrogens, the pyrazine central nitrogen of tpp z, and chlorine defining the best mean equatorial plane. The axial pos itions are occupied by the nitrogens of the coordinated pyridyl rings of tppz. The Ru-N(tppz) bond to the central ring is short [1.962(9) An gstrom], while the Ru-N(4,4'(CH3)(2)bpy) bond trans to it is lengthene d towards a single bond distance [2.096(10) Angstrom]. This enhances t he distortion in coordination of the octahedron, mainly produced by th e bite angle of tppz. The distortions in 1 are evident in the H-1-NMR spectra by the shifts of characteristic resonances upheld and downfiel d relative to the ligand.