Structurally Diverse Divalent Metal Adamantanedicarboxylate Coordination Polymers with Hydrogen‐bonding Capable Dipyridyl Pillaring Ligands

Abstract

Five new divalent metal coordination polymers containing either 1,3‐adamantanedicarboxylate (adc) or 1,3‐adamantanediacetate (ada) and pillaring dipyridyl ligands were prepared and structurally characterized by single‐crystal X‐ray diffraction. Using the V‐shaped linker 4,4′‐dipyridylamine (dpa), three new phases were isolated. {[Zn2(ada)2(dpa)2]·4.5H2O}n (1) shows a (4,4) grid topology with embedded octameric water clusters. {[Co(ada)(dpa)(H2O)]·H2O}n (2) also manifests a 2D dimensionality, but with an intriguing novel (4)(12)(4.125) looped topology. {[Cd(adc)(H2O)2]·H2O}n (3) did not incorporate dpa ligands during self‐assembly, but exhibits an uncommon 3‐connected 83 etb network topology. [Co(ada)(ebin)]n (4) [ebin = ethanediaminebis(nicotinamide)] possesses a (3,6) triangular net based on {Co2(OCO)2} dimeric units. {[Cd(adc)(ebin)]·2H2O}n (5) also shows dimeric units, although linked into a decorated (4,4) grid topology. Magnetic susceptibility studies of compound 4 revealed a decrease in χmT product upon cooling, ascribed to antiferromagnetic coupling concomitant with single‐ion effects [g = 2.39(2) with D = 40(3) cm–1 and J = –3.55(4) cm–1]. Compounds 1 and 5 undergo blue‐violet fluorescence upon ultraviolet irradiation; the zinc derivative 1 shows potential as a sensor for the solution‐phase detection of nitrobenzene and m‐nitrophenol. Thermal decomposition behavior of the five new phases is also discussed.