Alternative syntheses and reactivity of platinum(II) terpyridyl acetonitrile complexes

New direct syntheses of [Pt(trpy)(NCCH3)](CF3SO3)2 2 (where trpy = 2,2′:6′,2′′-terpyridine) and [Pt(tBu3-trpy)(NCCH3)](CF3SO3)2 3 (where tBu3-trpy = 4,4′,4″-tri-tert-butyl-2,2′:6′,2″-terpyridine) via the displacement of acetonitrile from [Pt(NCCH3)4](CF3SO3)2 have been developed. The synthetic utility of 2 was investigated in reactions with triphenylphosphine (PPh3), 2,6-dimethylphenyl isocyanide (CN-Xyl), 2,5-dimethyl-2,5-diisocyanohexane (TM4), and tert-butyl isocyanide (CN-tBu). Whereas the expected substitution products were observed for reactions with PPh3, CN-Xyl, and CN-tBu, dealkylation of TM4 occurred to afford [Pt(trpy)(CN)](CF3SO3) 6. The structures of [Pt(trpy)L]2+ dications show little intermolecular interactions in the solid state, with the exception of the tBu3-trpy complex 3 which exists as head-to-tail dimers with a Pt–Pt distance of 3.29 Å. The cyano product 6 was found to stack in infinite chains of cations with a Pt–Pt distance of 3.45 Å.