L. Pan et al., An unprecedented two-fold interpenetrated heterometallic 4(6)6(4) network constructed by five-connected copper metal nodes, CHEM COMMUN, (12), 2001, pp. 1064-1065
Hydrothermal reactions making use of dichromate metal anion as a secondary
ligand yielded a novel three dimensional, bimetallic copper(II)chromium(VI)
network with an unprecedented 4(6)6(4) topology consisting of Cu(II) ions
as five-connected nodes; two such networks, completely identical, interlock
to generate a two-fold interpenetrated structure.