Chloro[(1,2,3,4,5,6-eta)-2,2'',4,4'',6,6''-hexamethyl[1,1':3',1''-terphenyl]-2'-thiolato-kappaS][triisopropylphosphine-kappaP]ruthenium(II) (CAS# 1621182-04-4) is an organometallic reactant used to prepare hydrido-containing Ru(II) complexes as catalysts for regio- and chemoselective reduction of N-silylpyridinium ions.