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)] ⋅ 2H2O}n (1) and [Co(H2O)6]0.5[Co0.5(BCbpy)(H2O)2](m‐BDC) ⋅ 3H2O ⋅ 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. [ABSTRACT FROM AUTHOR]