title: Synthesis and Liquid-Crystalline Properties of Diazabutadiene Complexes of Rhenium(I).
abstract: New N,N '-bis(4-((4-alkoxybenzoyl)oxy)phenyl)-1,4-diaza-1,3-butadiene (L) ligands, obtained by condensation of 4-((alkoxybenzoyl)oxy)anilines and glyoxal, were complexed to different [ReX(CO)(3)] fragments to give the complexes [ReX(L)(CO)(3)] (X = Cl, Br, I) and [Re(CF(3)SO(3))(L)(CO)(3)].THF. The chloro and bromo complexes were obtained by direct reaction of the ligands with [ReX(CO)(5)] (X = Cl, Br), while the iodo and triflato derivatives were obtained via metathesis of the chloro or bromo precursors with potassium iodide or silver triflate respectively. The liquid-crystalline behavior of the ligands and the related rhenium complexes has been studied by means of optical microscopy, differential scanning calorimetry, and small angle X-ray diffraction. Nematic and smectic C phases were observed when the coordinated counteranions were Cl, Br, and I, respectively; the triflato derivatives were not mesomorphic.
authors.affiliation: Department of Chemistry, University of Exeter, Stocker Road, Exeter EX4 4QD, U.K., and Groupe des Matériaux Organiques, Institut de Physique et Chimie des Matériaux de Strasbourg, 23 Rue du Loess, 67037 Strasbourg Cedex, France.
authors.forename: Stefania
authors.initials: S
authors.lastname: Morrone
authors.forename: Daniel
authors.initials: D
authors.lastname: Guillon
authors.forename: Duncan W.
authors.initials: DW
authors.lastname: Bruce