Synthesis of new silica xerogels based on bi-functional 1,3,4-thiadiazole and 1,2,4-triazole adducts

New transparent Silica-based hybrid materials were synthesized by reaction of polymethylhydrosiloxane (PMHS) and organic compounds: 1,3,4-thiadiazole-2,5-diamine (1), 1,3,4-thiadiazole-2,5dithiol (2) and 1H-1,2,4-triazole-3-thiol (3), in tetrahydrofuran as solvant using hexachloroplatinic acid (H2PtCl6 center dot 6H(2)O) as a catalyst. PMHS was used as a principal network forming agent, it has been cross-linked via hydrosilylation reaction with bi-functional heterocyclic compounds, leading to the formation of colored gels. These later dried (xerogels) were characterized by numerous techniques, including spectroscopy of (FT-IR) and C-13 and Si-29 CP MAS NMR. The xerogels morphology and texture were studied by scanning electron microscopy and Brunauer-Emmet-Teller method. According to N2-physisorption results, isotherms are classified as type IV with H2 type hysteresis loop; then, the xerogels are mesoporous materials. The optic and magnetic properties of the obtained materials were studied by UV-VIS and EPR spectroscopies, respectively. This study showed that all materials are paramagnetic semiconductors. [GRAPHICS] .