Novel Layered 2D and Triply Interpenetrating 3D Cobalt-Functionalized Diaza-12-crown Based Coordination Polymers: Synthesis, Structure, and Magnetic Properties

Two novel coordination polymers with formulas CoL1·3H2O [1, L1 =
3,3′-((1,7-dioxa-4,10-diazacyclododecane-4,10-diyl)­bis­(methylene)
dibenzenecarboxylate] and Co2L2(H2O)2·2­(H2O) [2, L2 = 5,5′-((1,7-dioxa-4,10-diazacyclododecane-4,10-diyl)­bis­(methylene))
diisophthalate] were synthesized, where one Co­(II) ion coordinates
the crown-4 moiety of the ligand. Compound 1 crystallizes
in the space group C2 as an infinite two-dimensional
chiral layered coordination network with a tetragonal 44 sql net topology. The structural unit consists of the
coordinated Co­(II) ion and the deprotonated ligand. The Co­(II) ion
is 6-coordinate with two nitrogen atoms and two oxygen atoms of the
crown 1,7-diaza-12-crown-4, and two carboxylate oxygen atoms from
neighboring ligands, and exhibits a highly distorted octahedral geometry.
Compound 2 crystallizes in the monoclinic space group P21/n as a triply interpenetrating
3D network with the uncommon sqc528/dmd system, the first
coordination polymer with a 3-fold interpenetrating dmd topology.
It exhibits two distinct Co­(II) ions. One is in the center of the
crown-4 along with two cis-coordinated water molecules
in a highly distorted octahedral geometry; the other is 4-coordinate
with tetrahedral geometry and a node in the framework. Weak antiferromagnetic
interactions exist between the cobalt centers in both compounds.