Interpenetrating digold(i) diacetylide macrocycles

The cyclic dialkynyldigold(I) complexes [1,2-C2H4(O-3-C6H4OCH2CCAu)2(μ-LL)] were prepared by reaction under basic conditions of the dialkyne 1,2-C2H4(O-3-C6H4OCH2CCH)2 with [AuCl(SMe2)] and the corresponding diphosphine ligands LL = Ph2P(CH2)nPPh2 (n = 1–6), trans-Ph2PCHCHPPh2 and Ph2PCCPPh2. The new organometallic macrocycles have ring sizes ranging from 23 to 28 atoms, and the complexes with LL = Ph2P(CH2)4PPh2 and trans-Ph2PCHCHPPh2 have been structurally characterized. In both cases, the digold(I) macrocycles assemble into dimers in the solid state through Au⋯Au aurophilic bonding, with a phenyl group of each macrocycle occupying the cavity of the other. However, this extensive interpenetration occurs without the catenation observed in some similar complexes. The complexes give room temperature emissions above 400 nm in solution and the solid state, and a red shift of approximately 50 nm between emission maxima in the solution and the solid state spectra is suggested to be an indication of the strong interpenetration in the solid state.