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

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-ene1,2-cis-dicarboxylate) possesses a 3D pcu network based on embedded {Co-2(OCO)(2)} dimeric units. {[Co(cis13cdc)(bpmp)(H2O)]center dot 2H(2)O}(n) (2, cis-13cdc= cyclohexane-1,3-cis-dicarboxylate) exhibits (4,4) sawtooth coordination polymer layers polycatenated in a 2D+ 2D -> 3D parallel fashion. {[Co-2(cis-14cdc)(2)(bpmp)]center dot 2H(2)O}(n) (3, cis-14cdc= cyclohexane-1,4-cis-dicarboxylate) also shows (4,4) grid layer structures, but without any interpenetration. {Co-2(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 6(5)8 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.