An unusual (10,3)-d MOF material with nanoscale helical cavities and multifunctionality

Article abstract of DOI:10.1002/ejic.201100566

The Mn^II and Cu^II compounds of 3-(2-pyridyl)-5,6- diphenyl-1,2,4-triazine-4,4'-disulfonic acid (H₂pdtd) were synthesized and systematically characterized. The metal-organic framework (MOF) [Mn₂(pdtd)₂(H₂O)₄] _n·5nH₂O (1) was constructed by a solvothermal method preformed at 140 °C with methanol as the solvent, while [Cu(pdtd)(H₂O)₄]·H₂O (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 CO₂ sorption, and magnetic coupling. In contrast, 2 is a mononuclear complex with coordinated water and lacks functional properties. A (10,3)-d metal-organic framework, [Mn₂(pdtd) ₂(H₂O)₄]_n·5nH₂O (1), containing the asymmetrical 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-P,P'- disulfonate ligand (pdtd) was constructed. XRD analysis revealed that 1 is an acentric structure possessing exposed uncoordinated nitrogen atoms within helical cavities. 1 exhibits multifunctionality: nonlinear optical activity, CO₂ sorption, and magnetic coupling.