Diverse 2D and 3D topologies in cobalt cyclohexyldicarboxylate coordination polymers with bis(4-pyridylmethyl)piperazine coligands

Abstract Hydrothermal reaction of cobalt nitrate, a cyclohexyldicarboxylic acid, and the long-spanning dipyridyl coligand bis(4-pyridylmethyl)piperazine (bpmp) produced four structurally diverse coordination polymers which were characterized by single-crystal X-ray diffraction. [Co(cis-12chedc)(bpmp)]n (1, cis-12chedc = cyclohex-4-ene-1,2-cis-dicarboxylate) possesses a 3D pcu network based on embedded {Co2(OCO)2} dimeric units. {[Co(cis-13cdc)(bpmp)(H2O)]·2H2O}n (2, cis-13cdc = cyclohexane-1,3-cis-dicarboxylate) exhibits (4,4) sawtooth coordination polymer layers polycatenated in a 2D + 2D → 3D parallel fashion. {[Co2(cis-14cdc)2(bpmp)]·2H2O}n (3, cis-14cdc = cyclohexane-1,4-cis-dicarboxylate) also shows (4,4) grid layer structures, but without any interpenetration. {Co2(OCO)4} paddlewheel dimers are seen in chain-like substructures in 3. The minor phase [Co(cis-14cdc)(bpmp)(H2O)2]n (4) was isolated along with 3 and manifests a non-interpenetrated 658 cds topology 3D network. Thermal properties of 1–3 were also investigated. Variable temperature magnetic susceptibility studies showed dimer-based antiferromagnetic behavior for 1 and 3.