THE CRYSTAL-STRUCTURE OF NE)(PYRAZINE)(2,2'6',2''-TERPYRIDINE)RUTHENIUM(II) HEXAFLUOROPHOSPHATE

The crystal structure of [Ru(terpy)(bpy)(pz)](PF6)(2) has been determi ned by X-ray diffraction methods and refined to a residual of 0 . 046 for 1855 independent observed reflections. The crystals are monoclinic , space group P2(1)/a, a 16 . 836(7), b 10 . 778(5), c 19 . 342(5) Ang strom, beta 115 . 11(3)degrees. The coordination geometry around the r uthenium(II) ion is distorted octahedral, with the various Ru-N bond l engths indicative of considerable interligand steric strain. The Ru-N pyrazine bond is the longest within the structure, consistent with oth er evidence that pi back-bonding to pyrazine is weak in the complex.