Thermodynamically stable MOF showing a highly rare four-connected hxg-d-4-Cccm net with self-penetration, polyrotaxane, and polycatenane multi-features†
Abstract
Two different crystals, namely Zn2(L)2(AzDC)2·(H2O)2 (1) and Zn2(L)2(AzDC)2 (2) (L = N2,N6-di(pyridin-4-yl)pyridine-2,6-dicarboxamide, H2AzDC = azobenzene-4,4′-dicarboxylic acid), have been co-crystallized in a one-pot reaction, where 1 is a thermodynamically stable product, as only a few crystals of 2 are observed in this system and after holding in the original solution for more than three hours the crystals of 2 transform to become 1. Notably, 1 represents a highly rare hxg-d-4-Cccm net with self-penetration and polyrotaxane and polycatenane multi-motifs, whereas a common sql net with three-fold interpenetration is observed for 2.