Structural diversity in cobalt camphorate coordination polymers with flexible dipyridylamide ligands including looped layers and self-penetrated topologies

Abstract

Hydrothermal reaction of cobalt nitrate, d-camphoric acid, and flexible dipyridylamide ligands afforded a series of coordination polymers with diverse structural topologies, as characterized by single crystal X-ray diffraction.{[Co2(dl-cam)2(edn)]·2H2O}n (1, edn = N,N′-(ethane-1,2-diyl)dinicotinamide) shows a 3D 41263pcu net built from straight-pillaring of {Co2(OCO)4} paddlewheel dimer-based [Co2(dl-cam)2]n layer motifs. In contrast, [Co(d-cam)(edin)]n (2, edin = N,N′-(ethane-1,2-diyl)diisonicotinamide) manifests a two-fold parallel interpenetrated looped layer topology. {[Co2(dl-cam)2(bdin)]·2H2O}n (3, bdin = N,N′-(butane-1,4-diyl)diisonicotinamide) displays a very rare 3D 446108 roa self-penetrated net built from cross-pillaring of {Co2(OCO)4} paddlewheel dimer-based [Co2(dl-cam)2]n layer motifs, as does {[Co2(dl-cam)2(pedin)]·2H2O}n (4, pedin = N,N′-(pentane-1,5-diyl)diisonicotinamide). [Co(d-cam)(hdin)]n (5, hdin = N,N′-(hexane-1,6-diyl)diisonicotinamide) shows a simple stacked system of sawtooth (4,4) grid motifs. Thermal properties are discussed herein.