Three Hydrogen-Bonded Metal-Organic Networks with Tunable Semiconductor Properties

Solvothermal reacition of 2,4,6-tris(pyrezole-1-yl)-1,3,5-s-triazine (TPTz) and three metal ions resulted in the formation of three hydrogen-bonded metal-organic networks. It's found that 6-(pyrezole-1-yl)-1,3,5-triazine-2,4-diol (H2L) hydrolyzed from TPTz acts as the ligand in reality. Single-crystal structure analysis shows that the three compounds are isomorphous with the formula of [M(HL)(2)]center dot 2H(2)O (M=Zn, 1; Co, 2; Mn, 3). The center metal ion is six-coordinated by two N atoms from pyrazolyl, two N atoms from triazine ring and two 0 atoms from waters, respectively. Two HL- coordinate to one center metal ion forming a zero-dimensional metal-organic molecular, which was linked by the hydrogen bond, and then extended to a two-dimensional layer network. UV-Vis DRS analysis shows that they are all wide band semiconductors with a band-gap of 3.80 (Zn), 3.30 (Co), 3.27 (Mn) eV, respectively, showing an obvious dependence on their center metal ions. CCDC: 904985, 1; 904986, 2; 904987, 3.