Crystal Structure and Photochromic Properties of Two Complexes based on 1-(4-carboxybenzyl)-4,4 '-bipyridinium Ligand

Selecting different metal ions, two novel complexes {[Zn(BCbpy)(m-BDC)(H2O)] center dot 2H(2)O}(n) (1) and [Co(H2O)(6)](0.5)[Co-0.5 (BCbpy)(H2O)(2)](m-BDC) center dot 3H(2)O center dot DMF (2) have been prepared and structurally characterized in the presence of the viologen ligand 1-(4-carboxybenzyl)-4,4'-bipyridinium (BCbpy) and 1,3-benzenedicarboxylic acid (m-H2BDC). The crystal structures and photochromic properties of two complexes have been investigated in this article. 1 possesses a two-dimensional (2D) layered structure, while the structure of 2 is zero-dimensional (0D). As expected, 1 and 2 were discovered to be photochromic accompanying electron transfer (ET). Interestingly, 1 can be dissolved in ethanol solution and deposited on filter paper, applied to a printing medium without ink.