Composite materials based on SiO2-matrices saturated with DAST

Abstract In the present work the synthesis, structure and spectral properties of SiO2-matrices of different porosity (23%, 48% and 78%) doped by 4-N,N-dimethylamino-4′-N’-methyl-stilbazolium tosylate (DAST) are described for the first time. DAST does not form microcrystals into pores of the matricies, but probably exists as layers ordered by electrical fields of SiO2 surfaces. Growth of the pores size leads to increase of disordered cation fraction. Comparison of the half-width of the emission band (near 600 nm) of the DAST methanol solutions (2200 cm−1), of the composites based on the matrices with narrow pores (1835 cm−1), of the composites based on matrices with large pores and porosity of 48% and 78% (2000 cm−1) and of the DAST crystal (1855 cm−1) shows the highest ordering of DAST cations in the matrices with low porosity (23%). SiO2:DAST composites are the new materials, whose spectral properties can be tuned by changing the pores size.