Unusual Coordination Assemblies from Platinum(II) Thienyl and Bithienyl Complexes

Dinuclear Pt2Br2(dppf)2(μ-C8H4S2) exchanges with isonicotinic acid to release free bithiophene and gives a molecular
square [Pt4(dppf)4(μ2-O2CC5H4N)4]4+4OTf- which is an “all-ring” system with four Pt rings disposed at the corners
of a larger macrocyclic ring. The related mononuclear complex PtBr(η1(C2)-C4H3S)(dppf) reacts with AgOTf (OTf
= triflate) to give [Pt2(dppf)2(μ2,η1(C),η1(S)-C4H3S)2]2+2OTf- with an unusual six-membered ring formed by the
fusion of two Pt−thienyl entities at the sulfur sites. All the complexes are structurally characterized by single-crystal
X-ray crystallography.