Luminescence of tris(2,2'-bipyridine)ruthenium(II) in sol-gel glasses

Luminescence quenching of tris(2,2′-bipyridine)ruthenium(II) by 2,6-dimethylphenol and 4-bromo-2,6-dimethylphenol in sol–gel-processed silicate thin films

“…This blue shift on the emission spectra has been previously reported and discussed in detail for related chargetransfer compounds doped into sol-gel materials [15,[19][20][21].…”

The photophysical properties of ruthenium polypyridyl complexes within a sol-gel matrix

“…For [Ru(bpy)3] 2+ the increase in energy of the luminescence maximum has been explained by the restriction in solvent movement around the excited molecule [9] which has the result that the 3MLCT excited state is not completely stabilised within its lifetime. It is known that the isoelectric point of colloidal silica is approximately 2 [12].…”

“…When considering the final lifetimes of the doped gels, two effects should be taken into account. The first effect is that of surface charge, with the negatively charged surface impeding vibrational deactivation of the excited state complex by electrostatic interaction to a greater extent than the positively charged surface [9]. The second effect involves the density of the host gel.…”

“…Because it is a low temperature process, organic and biological molecules with poor thermal stability can be encapsulated intact in the inorganic glass while retaining their optical properties [7]. It has been shown previously that the photophysical behaviour of the [Ru(bpy)3] 2+ cation (bpy = 2,2'-bipyridine) is dramatically altered upon incorporation within a sol-gel matrix [7][8][9]. To date, most of the work in this area has focused only on immobilised [Ru(bpy)3] 2+ (Fig.…”

Non-hydrolytic sol–gel synthesis and characterization of Eosin-Y doped titanosilicate thin films for waveguiding applications

“…8, a y-axis offset is applied to samples A and C for visibility). The blue shift in samples A and B may be caused by immobilization of the dye in sol-gel matrix during the sol-gel process (Matsui et al, 1991), while for sample C in which TiO 2 dominates, the environment does not change. This is as a result of different electrostatic interaction between the dye cation and negatively charged SiO 2 (Pouxviel et al, 1989) or positively charged TiO 2 (Amadelli et al, 1990).…”