Macrocyclic gold(I) complexes and [2]catenanes containing carbonyl functionalized diacetylide ligands

The carbonyl derivatized bis(alkyne) OC(4-C6H4OCH2CCH)2 was converted into the imine derivatives RNC(4-C6H4OCH2CCH)2 [R=OH, NHC(O)NH2, NHC6H3-2,4-(NO2)2] and into the 4-bromomethyl-1,3-dioxolane derivative BrCH2C2H3O2C(4-C6H4OCH2CCH)2. The alkyne units in these compounds react with [AuCl(SMe2)] in the presence of base to form the corresponding digold(I) diacetylide complexes, that exist as insoluble oligomers or polymers. They reacted with the diphosphines Ph2PZPPh2 [Z=CC, trans-HCCH and (CH2)n, n=3–5] to give macrocyclic gold(I) complexes of the type [Au2(μ-LL)(μ-PP)], where LL is the diacetylide and PP the diphosphine ligand. The ability of these macrocyclic complexes to self-assemble to [2]catenanes has been studied. The ketone and imine derivatives do not form [2]catenanes because the orientation of the aryl groups is unfavorable, but the 1,3-dioxolane derivatives may catenate if the ring size is optimum.