Influence of Ligand Geometry on the Dimensionality of Sn(II) Benzenedicarboxylate Crystal Structures

Four new divalent tin benzenedicarboxylates (bdc) have been synthesized by hydrothermal techniques, and their structures have been determined from single crystal X-ray data. A chiral complex layer is formed by Sn-II and 1,2-bdc. In Sn(1,2-bdc)-II (2), such layers are stacked in a AA pattern, leading to a chiral and polar structure with the space group symmetry C2, while in Sn(1,2-bdc)-I (1) the same layer is alternately stacked with the mirror-image layer, leading to a structure with the space group C2/c. The one-sided coordination of Sn-II combined with the 120 degrees angle of the carboxylate groups in 1,3-bdc results in the tubular structure of Sn(1,3-bdc) (3). The tubes are connected by very weak intertube Sn-O bonds. The compound Sn3O(1,4-bdc)(2) (4) has a 3D framework structure based on Sn3O triangular secondary building units that are cross-linked by the 1,4-bdc ligands. Strong pi-pi interactions occur between the neighboring phenyl rings.