Self-assembly of rings, catenanes, and a doubly braided catenane containing gold(I): The hinge-group effect in diacetylide ligands

Reaction of the flexible dialkynyldigold(I) precursors X(4-C6H4OCH2C- CAu)( 2) with 1,4-bis(diphenylphosphino)butane gave complexes of formula [{[mu -X (4-C6H4OCH2CCAu)(2)][mu-(Ph2PCH2CH2CH2CH2PPh2)]}(n)]. The complexes exist a s 25-membered ring compounds with n = 1 when X = O or S, as [2]catenanes wi th n = 2 when X = CH2 or CMe2, and as a unique doubly braided [2]catenane, containing interlocked 50-membered rings with n = 4 when X = cyclohexyliden e. These compounds form easily and selectively by self-assembly; reasons fo r the selectivity are also discussed.