Structural and Spectroscopic Studies on Cu(DACH)2(H2O)Cl2(DACH =1,4-Diazacycloheptane)

摘要

A penta-coordinated Cu(Ⅱ) complex with 1,4-diazacycloheptane (DACH), [Cu(DACH)2(H2O)]Cl2(1), has been synthesized and characterized by X-ray diffraction, IR spectra,elemental analyses, thermal analyses, UV-Vis and ESR techniques. Complex 1 crystallizes in orthorhombic crystal system, Pbcn space group with a = 1.6075(4), b = 1.0539(3),c=0.9195(3) nm, V=1.5578(7) nm3, Mr=352.79, Z=4, Dc=1.487 g/cm3, final R=0.0451 and wR =0.1294.The structure of 1 indicates that the central Cu(Ⅱ) atom is penta-coordinated by four nitrogen atoms of two DACH moieties at the equatorial positions and a water molecule at the axis position. The coordination geometry of Cu(Ⅱ) could be considered as an approximately ideal square-pyramidal environment. Both DACH rings arrange in cis-form and are predominantly in the boat-boat conformation (80%) with some disorder to the chair-chair conformation (20%). The Cl- anions are hydrogen bonded with the nitrogen donors of the DACH rings and the oxygen donor of the coordinated H2O molecule to form a one-dimensional zigzag linear structure.The solution behaviors of 1 are also discussed in detail by Uvvis and ESR technique.