Topological control through the solvent effect in two-dimensional cadmium coordination polymers

Two new solvent-induced cadmium (II) coordination polymers, {[CdL1.5(NO3)2](CH3CN)}n (1) and [CdL (NO3)2(H2O)]n (2) were successfully synthesized from the same initial materials Cd(NO3)2.4H2O and 1,4-bis(3pyridyl)-2,3-diaza-1,3-butadiene (L) in EtOH/CH3CN and CH3CN solvent systems, respectively. These coordination polymers were structurally characterized by single-crystal X-ray diffraction analysis and further identified by infrared spectra (FTIR) and powder X-ray diffraction (PXRD). The influence of the solvent system can be observed by a significant change in the topological features. As controlled by solvent, compound 1 shows a 2D coordination polymer that can be simplified as a (6,3) net, while compound 2 is two-dimensional (4,4) coordination network. Our results provide interesting insights into solvent effects on the topological control in construction of non-interpenetrated coordination polymers. Hirshfeld surface analysis of the structures 1 and 2 is used to investigate the percentage of participation of intermolecular interactions in the crystal packing of compounds 1 and 2.