Effect of Organic Polymer Additive on Crystallization of Porous Coordination Polymer

Poly(vinylsulfonic acid, sodium salt) (PVSA) is a polymer capable of complexing and stabilizing Cu 2+ by electrostatic interaction, which affects crystallization of a porous coordination polymer [{Cu 2 pzdc 2 (pyz)} n ] (pzdc = pyrazine-2,3-dicarboxylate, pyz = pyrazine; 1 ) in the self-assembly process. It is shown that the addition of PVSA to the reaction mixtures significantly affects the nucleation process of 1, which determines the crystal size of 1 in the range of 1−100 μm. Scanning electron microscopy, X-ray powder diffraction, and electron diffraction measurements show that PVSA controls not only the crystal size and shape but also the preferential orientation of the plate crystals, which results in alignment of the channel direction of 1 in the bulk powdery state. The N 2 adsorption measurement of each sample showed characteristic typical micropore adsorption isotherms independent of the crystal size of 1; however, the adsorption speed for the samples showed a novel size-dependent feature because of changes in the diffusion length of N 2 in the one-dimensional channels of 1 .