Gold and platinum benzenehexathiolate complexes as large templates for the synthesis of 12-coordinate polyphosphine macrocycles

A general strategy for the synthesis of large-ring, poly-donor macrocycles using multi-metal ion templates is outlined. This strategy is illustrated in the design and synthesis of the hexanuclear (divinyl)(phenyl)phosphine gold complex of benzenehexathiolate, {[(C2H3)2(Ph)P]Au}6(C6S6) (1), which undergoes macrocycle formation upon reaction with PhPH2 in the presence of AIBN (Scheme 1). NMR spectra (1H and 31P) and elemental analyses indicate that the resulting macrocycle is a 36-membered ring containing 12 phosphorus donors, six of which are coordinated to the six Au atoms in the Au6(C6S6) core. A series of tri-platinum complexes, [(P∩P)Pt]3(C6S6) (16–19), where (P∩P) is a bidentate phosphine ligand, with three (P∩P)PtII units coordinated to a C6S6 6− core, were also prepared as models for templated formation of other poly-phosphorus macrocycles.