Donor disposition and aliphatic conformation effects on structure in luminescent zinc dicarboxylate coordination polymers with isomeric dipyridylamide coligands

Abstract

Hydrothermal reaction of zinc nitrate, a four-carbon chain dicarboxylic acid, and one of three isomeric dipyridylamide coligands has afforded a family of six new coordination polymers, which have been structurally characterized by single-crystal X-ray diffraction. The binding modes and conformations of the dicarboxylate ligands and the nitrogen donor disposition within the dipyridylamide coligands provide crucial structure-directing roles in this system. {[Zn(fum)(3-pina)]·1.5H₂O}_n (1, fum = fumarate, 3-pina = 3-pyridylisonicotinamide) has a 4-fold interpenetrated 4³6²8 sra topology. [Zn(fum)(4-pna)]_n (2, 4-pna = 4-pyridylnicotinamide) possesses a 4-fold interpenetrated 6⁶dia topology, while [Zn(fum)(4-pina)]_n (3, 4-pina = 4-pyridylisonicotinamide) has a 2-fold interpenetrated 4¹²6³pcu topology with dimeric cluster nodes. [Zn₃(mal)₂(OH)₂(4-pina)₂]_n (4, mal = maleate) has neutral [Zn₃(mal)₂(OH)₂]_n ribbons linked into a (3,6) triangular layer. [Zn(suc)(4-pina)]_n (5, suc = succinate) displays an uncommon 6-connected self-penetrated 4⁴6¹⁰8 mab topology, while instead [Zn(suc)(4-pna)]_n (6) has a simple corrugated (4,4) grid structure. Thermal and luminescent properties of these new materials have also been investigated.