Cocrystallization of a dinuclear platinum complex as a monomer and a one-dimensional polymer

Abstract

The reaction of Pt(DMB)Cl2 (DMB/3,3?-dihydroxymethyl-2,2?-bipyridine) with AgF3CSO3 in H2O yielded a dimeric platinumcomplex, [{Pt(DMB)(m-OH)}2]2(F3CSO3)4 /2H2O. X-ray structure reveals that two conformational isomers are self-assembled bydifferent hydrogen bonding motifs in one crystal, resulting in a new type of co-crystal of monomer and its polymer. One conformeris self-assembled into the one-dimensional polymeric chain by strong hydrogen bonds, while the other conformer of which possiblehydrogen bond donors/acceptors are blocked by two triflate anions exists as an isolated molecule itself. DFT calculations show thatthe strong hydrogen bonds and crystal packing force might compensate for the energy gap of /14 kcal mol1 between twoconformers and the conformational energetics are dominated by the energies of the coordinated ligands rather than those ofhydroxo-bridged platinum cores.