An Unusual (10,3)‐d MOF Material with Nanoscale Helical Cavities and Multifunctionality

The Mn II and Cu II compounds of 3‐(2‐pyridyl)‐5,6‐diphenyl‐1,2,4‐triazine‐4,4′‐disulfonic acid (H 2 pdtd) were synthesized and systematically characterized. The metal‐organic framework (MOF) [Mn 2 (pdtd) 2 (H 2 O) 4 ] n · 5 n H 2 O ( 1 ) was constructed by a solvothermal method preformed at 140 °C with methanol as the solvent, while [Cu(pdtd)(H 2 O) 4 ] · H 2 O ( 2 ) was obtained by conventional solution chemistry conducted at 80 °C. Crystallographic analysis revealed that 1 has an acentric structure in which the Mn II centers are linked via sulfonate groups and chelating nitrogen atoms within the pdtd ligands to give a rare noninterpenetrating (10,3)‐d framework with permanent helical cavities. Consequently, 1 exhibits nonlinear optical (NLO) activity, significant CO 2 sorption, and magnetic coupling. In contrast, 2 is a mononuclear complex with coordinated water and lacks functional properties.