Three inorganic–organic hybrids of bismuth(III) iodide complexes containing substituted 1,2,4-triazole organic components with charaterizations of diffuse reflectance spectra

The reactions of two kinds of substituted 1,2,4-triazoles with BiI3 yielded three inorganic–organic hybrids: [HL1]4[Bi6I22]·[L1]4·4H2O (1) (L1=3-(1,2,4-triazole-4-yl)-1H-1,2,4-triazole); [HL2]4[Bi6I22]·6H2O (2); [HL2]2[Bi2I8]·[L2]2 (3) (L2=(m-phenol)-1,2,4-triazole). Both 1 and 2 have polynuclear anions of [Bi6I22]4– to build up the inorganic layers and substituted 1,2,4-triazoles as the organic layers. Hybrid 3 consists of two BiI5 square pyramids as inorganic layers. There exist hydrogen bondings and I⋯I interactions in the structures of 1, 2 and 3. Optical absorption spectra of 1, 2 and 3 reveal the presence of sharp optical gaps of 1.77, 1.77 and 2.07 eV, respectively, suggesting that these materials behave as semiconductors.