Ionic columnar metallomesogens formed by three-coordinated copper(I) complexes

Two series of copper(I) complexes (1, 2) derived from bis{2-[3'-(3",4"-dial koxyphenyl)-5'-methyl-1'-pyrazolyl]ethyl} prepared and ethers and from bis{ 2-[3'-(3",4",5'-trialkoxyphenyl)-5'-methyl-1'-pyrazolyl]ethyl} ethers were characterized. These ionic copper(I) complexes were obtained by reaction of the ethers with [Cu(McCN)(4)]BF4 in refluxing acetonitrile. All three-coor dinated copper(I) complexes isolated as off-white solids were characterized by NMR spectroscopy and elemental analysis, and their mesomorphic properti es were also studied by polarized optical microscopy, differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). Results indicated th at these complexes exhibited hexagonal columnar phases (Col(h)). The cleari ng points of all compounds were relatively low (94-112 degreesC) and the te mperature range of the mesophases was ca. 45-68 degreesC. Powder XRD diffra ction patterns showed three sharp reflections in the small angle region cor responding to a ratio of their positions of I : (1/3)(1/2): (1/2), indicati ng typical hexagonal columnar phases.