title: Dinuclear gold(I) isocyanide complexes with luminescent properties, and displaying thermotropic liquid crystalline behavior.
abstract: Dinuclear gold(I) complexes [mu-(4,4'-CN-R-NC){Au(C6F4OC4H9)}2] [R = 1,4-phenylene, n = 8; R = 4,4'-biphenylene, 2,2'-dichloro-4,4'-biphenylene, 2,2'-dimethyl-4,4'-biphenylene, n = 4,6,8,10] have been prepared and their liquid crystal behavior and optical properties studied. Although the free ligands are not mesomorphic, all the gold(I) derivatives described, except the phenylisonitrilegold(I) derivative [mu-(1,4-CN-C6H4-NC){Au(C6F4OC8H17)}2], display liquid crystal behavior, giving rise to a nematic mesophase. The transition temperatures decrease in the order 4-4'-biphenylene > 2,2'-dichloro-4-4'-biphenylene > 2,2'dimethyl-4-4'-biphenylene. All compounds show photoluminescence in the solid state and in solution. The single-crystal X-ray diffraction structures of [mu-(4,4'-CN-R-NC){Au(C6F4OCnH2n+1)}2] (R = 4-4'-biphenylene and 2,2'-dichloro-4-4'-biphenylene) have been determined confirming the rodlike structure of the molecule, with a linear coordination around the gold atoms. There are Au...Au interactions in the 2,2'-dichlorobiphenyl derivative but not in the 4-4'-biphenyl compound.
authors.affiliation: Química InorgAnica, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain. espinet@qi.uva.es
authors.forename: Silverio
authors.initials: S
authors.lastname: Coco
authors.forename: Carlos
authors.initials: C
authors.lastname: Cordovilla
authors.forename: Pablo
authors.initials: P
authors.lastname: Espinet
authors.forename: José
authors.initials: J
authors.lastname: Martín-Alvarez
authors.forename: Paula
authors.initials: P
authors.lastname: Muñoz