A solvent stabilized cyclic dimer complex of platinum(II) with S2O2 macrocycle

Assembly reaction of L2 (5,8-dioxa-2,11-dithia[12]-m-cyclophane) with K2PtCl4 afforded a unique cyclic dimer complex [Pt2(L2)2Cl4] (1) but its whole conformation is disordered except two metal centers. Recrystallization of the same compound from dichloromethane afforded an isostructural product [Pt2(L2)2Cl4]CH2Cl2 (2) but without such disorder. In 2, each Pt atom is four-coordinated in a square-planar environment with two S atoms from different two L2s and to two Cl− ions in a cis arrangement showing a basket-like conformation. Very interestingly, one dichloromethane molecule found in the cyclic dimmer cavity stabilizes the whole structure of 2 by hydrogen bonds.