LIQUID-CRYSTALLINE (ISONITRILE)GOLD(I) ACETYLIDE COMPLEXES

The mesomorphic properties of three types of gold(I) acetylide complex es, [(ArNC)Au-C drop CAr, (ArNC)Au-C drop CR and (RNC)Au-C drop CAr, w here R and Ar represent alkyl and aryl groups, respectively] were syst ematically examined and it was found that of the three, (RNC)Au-C drop CAr (complex C) is the choice for liquid-crystalline materials, and t hat introduction of an appropriate lateral group on the isonitrile and /or acetylene ligands led to the formation of nematic and smectic A ph ases without any decomposition of the complexes. The linear geometry a round the central gold atom was confirmed by X-ray crystallographic an alysis of complex C-5b. The relation between the thermal behaviour and the molecular structure of the complexes is discussed.