MONONUCLEAR PYRIDINE-2-THIONATO COMPLEXES FORMED DIRECTLY FROM RUTHENIUM TRICHLORIDE

Reductive carbonylation of ruthenium trichloride in refluxing 2-methoxyethanol leads to a chlorocarbonyl complex of ruthenium(II) which reacts directly with pyridine-2-thione (pySH) to give high yields of [Ru(pyS)2(CO)2], and the 6-methylpyridine-2-thionato analogue is prepared similarly but in much lower yield. Quinoline-2-thione (quinSH) gives high yields of the compound [RuCl2(quinSH)2(CO)2] and only low yields of the dehydrochlorination compound [Ru(quinS)2(CO)2]. The more crowded thione, 4,8-dimethylquinoline-2-thione, gives only the chloro complexes and no dehydrochlorination.