Synthesis, crystal, luminescent properties and electronic structures of two copper(I) halide polymers based on Cu4I4 cubane tetramers

摘要

Two novel coordination polymers [Cu4I4(en)2]_n 1 and [Cu4I4(pn)2]_n 2 (en = 1,2-diaminoethane and pn = 1,3-diaminopropane) were prepared by hydrothermal methods and determined by single-crystal X-ray diffraction analysis. Compound 1 possesses a 3D zeolite-like architecture with infinite intersected channels, constructing from cubane Cu4I4 tetramers, which is simplified into a twofold interpenetrating dia network. Compound 2 with the similar Cu4I4 cores, features a 2D layer with parallelogram-shaped channels along the b axis, showing a uninodal sql net. Both exhibit luminescent emission bands at about 600 nm at room temperature when excited at 350 and 370 nm, respectively. Furthermore, thermogravi-metric analyses, optical diffuse reflectance spectroscopy, and the theoretical calculations were discussed.