Temperature-controlled assembly of two fluorescent ZnII polymers from 3D pillared-layer framework to 2D (4,4) layer

Two ternary coordination polymers with the same ingredients but different structures, [Zn-2(datrz)(2)(niP)](n) (1) and {[Zn(Hdatrz)(nip)]center dot H2O}(n) (2) (Hdatrz = 3,5-diamino-1.2.4-triazole; nip(2-) = 5-nitroisophthalate), were respectively obtained by temperature-controlled hydrothermal reactions and fully structural characterized. Interestingly, tetrahedral Zn-II ions in 1 are linked into wavy layers by anionic mu(3)-N1,N2,N4-datrz ligands, which are further supported by deprotonated bis-monodentate nip(2-) to generate a 3D pillared-layer framework. In contrast, the tetrahedral Zn-II ions in 2 are aggregated into a (4, 4) covalent layer through alternate mu(3)-N1,N4-Hdatrz and bis-monodentate nip(2-) bridges. Thus, the competitive binding of the two polydentate ligands to the metal ion plays essential roles on the connectivity and dimensionality of the two complexes. Thermal stability and the fluorescent emissions of the two complexes were also investigated and compared. (C) 2010 Elsevier B.V. All rights reserved.