Di-, tri-, tetranuclear clusters and polymeric cadmium compounds: Syntheses, structures and fluorescent properties with various linking fashions and high stability of orotates under the condition of strong bases

Assembly reactions of orotic acid (H3dtpc ) and CdCl2·2.5H2O or CdSO4·8H2O yielded four new cadmium compounds {[Cd(H2dtpc)(phen)(H2O)2]·(H2dtpc)·4H2O}2 (1: solution reaction, pH=4–5, in addition of phen), [Cd3(dtpc)2(phen)5]·13H2O (2: hydrothermal reaction, initial pH=14, final pH=7.5), [Cd(Hdtpc)(H2O)3]4 (3: solution reaction, initial pH=6.5, final pH=6.0), {[Cd(Hdtpc)(phen)(H2O)]·H2O}n (4: hydrothermal reaction, initial pH=8; final pH=6.5), respectively. Compounds 1–4 have been characterized by IR, thermogravimetric analyses (TGA), photoluminescence analyses, single-crystal and powder X-ray diffraction (PXRD). Compound 1 is a binuclear, 2 is a trinuclear, 3 is a tetranuclear structure, and 4 possesses one-dimensional chain framework, respectively, in which the orotate ligands show seven different linking fashions in 1–4. The orotate ligands as trivalence anions are observed in the formation of orotate-compounds, in which the orotates show high stability under the extreme condition of strong basic solution, high temperature and pressure.