Ruthenium carbonyl complexes. III. Peparations, properties and structures of Dicarbonyl- and Monocarbonyl-(2,2':6',2''-terpyridyl)ruthenium(II) complexes

Abstract

Reaction of 2,2':6',2''-terpyridyl (tpy) with ruthenium dicarbonyl dihalides yields the complexes Ru(CO)₂X₂(tpy) (X = Br or Cl), which can be protonated giving [Ru(CO)₂X₂(tpyH)]ClO₄. Crystal structures of the two forms (red and yellow) of Ru(CO)₂Br₂(tpy) show each to have octahedral stereo-chemistry with cis-carbonyls, trans-bromines, and bidentate tpy. Treatment of Ru(CO)₂X₂(tpy) complexes with trimethylamine N-oxide in dichloromethane at room temperature gives cis-Ru(CO)X₂(tpy) complexes. The presence of cis halogens and tridentate terpyridyl in the chloro complex has been established by X-ray crystallography. Reaction of terpyridyl with ruthenium trichloride in dimethylformamide yields trans-Ru(CO)Cl₂(tpy), the crystal structure of which has been determined.