Diaqua tetrabenzo (b,f,j,n,) {1,5,9,13} tetraazacyclohexadecine copper(II) and nickel(II) bisanthraflavates: crystal and molecular structure

Abstract

Charge transfer molecular solids [diaqua tetrabenzo (b,f,j,n,) {1,5,9,13) tetraazacyclohexadecine] Ni(II) and Cu(II) bisanthraflavates were synthesized and characterized by IR, Mass Spectrometry, TGA, and X-ray diffraction on single crystals. Unit cell dimensions (Å) a = 12.291(1), c = 14.574(1) Å and a = 12.434(1), c = 14.066(1) Å for Cu(II) and Ni(II) derivatives, respectively, space group P4₂/n in both cases. The obtained compounds show expected chemical and structural similarities. Tetraazamacrocycles are surrounded individually by a zig-zag, ribbon-like motif extending in the crystal by head-to-tail hydrogen bonding of monosubstituted anthraflavates. Electric conductivities were measured by the four points method as pellets from the variation of electric current through the sample as a function of temperature, for fixed voltages in the ohmic regime. Preliminary results indicate low conductivity values at room temperature but semiconductivity behaviour in the temperature range −150 to 170°C.