Crystal Structure of Coordination Polymers Based on Scandium and 2,5-Pyrazinedicarboxylic Acid

Abstract

In the interaction of scandium chloride hexahydrate and 2,5-pyrazinedicarboxylic acid (H2pzc) dihydrate in different solvent mixtures two novel coordination polymers are obtained under solvothermal conditions: [Sc2(dmf)2(H2O)2(pzc)3] (1) and [Sc2(H2O)2(pzc)3]·2CH3CN·H2O (2) (dmf is N,N-dimethylformamide). Crystal structures of compounds 1 and 2 are determined by single crystal X-ray diffraction and supported by elemental and thermogravimetric data and IR spectroscopy. The phase purity of the samples prepared is confirmed by powder X-ray diffraction. It is shown that the coordination environment of the scandium cation and the 2,5-pyrazinedicarboxylate ligand denticity change depending on the composition of a solvent mixture. Compound 1 has a layered structure while in the structure of 2 there is a three-dimensional framework.