SYNTHESIS AND LIQUID-CRYSTALLINE PROPERTIES OF DIAZABUTADIENE COMPLEXES OF RHENIUM(I)

New -alkoxybenzoyl)oxy)phenyl)-1,4-diaza-1,3-butadiene (L) ligands, ob tained by condensation of 4-((alkoxybenzoyl)oxy)anilines and glyoxal, were complexed to different [ReX(CO)(3)] fragments to give the complex es [ReX(L)(CO)(3)] (X = Cl, Br, I) and [Re(CF3SO3)(L)(CO)(3)]. THF. Th e chloro and bromo complexes were obtained by direct reaction of the l igands with [ReX(CO)(5)] (X = Cl, Br), while the iodo and triflato der ivatives were obtained via metathesis of the chloro or bromo precursor s with potassium iodide or silver triflate respectively. The liquid-cr ystalline behavior of the ligands and the related rhenium complexes ha s been studied by means of optical microscopy, differential scanning c alorimetry, and small angle X-ray diffraction. Nematic and smectic C p hases were observed when the coordinated counteranions were Cl, Br, an d I, respectively; the triflato derivatives were not mesomorphic.