Coexistence of Planar and Chair-Shaped Cyclic Water Hexamers in a Unique Cyclohexanehexacarboxylate-Bridged Metal−Organic Framework

The hydrothermal reaction of CoCl2·6H2O with cis,cis,cis,cis,cis-1,2,3,4,5,6-cyclohexane-hexacarboxylic acid (L) generates
a unique three-dimensional metal−organic framework (MOF) of [Co3(L-6H)(H2O)6]n (1). X-ray crystallography reveals that each L-6H
ligand changes its conformation to a trans,trans,trans,trans,trans form to connect nine Co(II) atoms, and each Co(II) atom is connected to
three L-6H ligands, leading to a MOF structure with high symmetry of R3̄. The coexistence of planar and chair-shaped cyclic water hexamers
is found in this MOF. Magnetic studies show the occurrence of the field-dependent magnetic transition.