Syntheses and Structures of Tetraplatinum Bis(polyynediyl) Complexes with Laterally Arrayed sp Carbon Chains

Reactions of trans,trans-(C6F5)(p-tol3P)2Pt(C⋮C)nPt(P-p-tol3)2(C6F5) (n = 3, 4) and Ph2P(CH2)3PPh2 (2.5 equiv) give the tetraplatinum complexes (95−81%), in which two sp carbon chains span two 12-membered-ring termini. Chain−chain interactions have been probed by crystallography, UV−visible spectroscopy, cyclic voltammetry, and thermolyses.