Solvothermal Subcomponent Self-Assembly of Cubic Metal–Imidazolate Cages and Their Coordination Polymers

A series
of Ni–imidazolate cubic cages, one-dimensional and two-dimensional
coordination polymers based on the cubic cages, have been prepared
by solvothermal subcomponent self-assembly of 5-methyl-4-formylimidazole, m-xylylenediamine, and NiII salts with varied
anions. These compounds have been characterized by single-crystal
X-ray diffractions, elemental analysis, IR spectra, and powder X-ray
diffractions. The formation of an oligomerized coordination cage or
an infinite coordination polymer depends on the anions chosen. An
oligomerized 8-nuclear Ni–imidazolate cubic cage is formed
when the anion Cl–, Br–, I–, SCN–, NO2–, or NO3– is utilized in the reactions,
and a two-dimensional coordination polymer based on the Ni–imidazolate cubic cage will be
obtained when N3–, (CN)2N–, or (CN)3C– act as the
anions. When only ClO4– or both ClO4– and [Ni­(C4N2S2)2]2– (C4N2S2 = dimercaptomaleonitrile) as anions exist in the reaction
mixture, a ladder-like one-dimensional coordination polymer based
on the Ni–imidazolate cubic cage and formate is formed unpredictably.