Solvatochromism as a probe to observe the solvent exchange process in a 1-D porous coordination polymer with 1-D solvent accessible channels.

A one-dimensional porous coordination polymer (PCP) {[Cu2(acetate)2(3,6-di(pyridin-4-yl)-1,2,4,5-tetrazine)]·2CHCl3}n possesses pleochroic properties. Solvent exchange with acetonitrile and nitromethane reveals that single crystals of the PCP are also solvatochromic, with the solvent exchange process occurring in an unexpected double V-shaped pattern. Crystal surface adsorption modeling shows that the origin of this effect is preferential sorption at two faces of the crystal.