LIQUID-CRYSTALS BASED ON HALOGOLD(I) COMPLEXES WITH P-ALKOXYPHENYL ISONITRILES

Rod-like complexes [AuCl(C=NC6H4OCnH2n+1-p)] (n=2, 4, 6, 8, 10, 12) ha ve been prepared by reaction of [AuCl(tht)] (tht=tetrahydrothiophene) with the corresponding isonitriles. Metathetical reactions with KBr or Kl afford the complexes [AuX(C=NC6H4OCnH2n+1-p)] (X=Br, I). The free isonitriles and iodo complexes are not liquid crystals, but the chloro derivatives (n greater than or equal to 4) and the bromo complexes (n greater than or equal to 6) display a wide range of smectic A phases. This behavior suggests a determining influence of the polarity of the Au-X bond in the stabilization of the mesophase. All the complexes sh ow high thermal stability, even in the isotropic state.