A cobalt coordination polymer with a new 6-connected self-penetrated topology and its high temperature layered polymorph

Abstract

Crystals of {[Co2(cpp)2(dpa)2]·2.5 H2O}n (1, cpp = 3-(4-carboxyphenyl)propionate, dpa = 4,4′-dipyridylamine) were prepared by hydrothermal methods. A single-crystal structure determination showed the presence of 2-fold interpenetrated lvt topology [Co2(cpp)2]n networks, which feature ferromagnetically coupled {Co2(OCO)2} dimeric units. The interpenetrated [Co2(ccp)2]n networks are pillared by pairs of dpa ligands to give an unprecedented dimer-based 6,6-connected binodal self-penetrated network with overall (32556672)(34425465) topology. A higher temperature synthetic scheme afforded [Co(cpp)(dpa)(H2O)]n (2), which displays a simpler (4,4) grid sawtooth layered topology.