One-Dimensional Copper(II) Complexes Containing Only Single End-On Azido Bridges: Crystal Structures and Magnetic Properties
journal contributionposted on 04.05.2005, 00:00 by En-Qing Gao, Yan-Feng Yue, Shi-Qiang Bai, Zheng He, Chun-Hua Yan
Two one-dimensional (1D) azido-bridged coordination polymers of formula [Cu(L)(μ-1,1-N3)(N3)]n (1) and [Cu(L)(μ-1,1-N3)(N3)]n (2) have been synthesized and structurally characterized, and their magnetic properties have been studied, where L1 and L2 are the bidentate Schiff bases obtained from the condensation of 2-pyridylaldehyde with aniline and p-chloroaniline, respectively. Both compounds consist of 1D uniform chains in which the Cu(II) ions with a distorted square pyramidal geometry are interlinked by single end-on azido bridges in the asymmetric basal−apical fashion, and the chains are interlinked by weak C−H···N hydrogen bonds into two-dimensional (2D) layers. They represent the first examples of metal azido complexes containing only single end-on azido bridges. Temperature- and field-dependent magnetic analyses reveal that weak antiferromagnetic interactions are mediated by the single asymmetric bridges, with the exchange parameters being −2.2 and −3.7 cm-1 for 1 and 2, respectively.