Synthesis of novel fluorene-functionalised nanoporous silica and its luminescence behaviour in acidic media

Abstract

Fluorene-functionalised nanoporous silica (FL-NH2-SBA-15) was prepared using the post-synthesis grafting method of SBA-15. The material thus obtained was characterised by means of small- and wide-angle X-ray diffraction, nitrogen adsorption-desorption, Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and elemental analysis. The results showed that the organised structure is preserved after the post-grafting procedure. Surface area and pore-size decreased by attaching functional groups to the pore surface. In addition, the pore volume was reduced with functionalisation. The amount of fluorene grafted onto the surface of SBA-15 was 0.55 mmol with a yield of approximately 46 %. The emission spectra of FL-NH2-SBA-15 in acidic media were studied and are discussed in detail. The structural change between FL-NH2-SBA-15 and the protonated form might be an effective candidate for acid-dependent molecular-sensor models for advanced application in molecular sensors in the future.

Physico-chemical characteristic of “Gajner Lake” in Arid Region of Rajasthan

“…Nitrate was estimated maximum (4.7 mg/L) in the summer season and minimum (2.4 mg/L) in the rainy season. Similar results were also recorded by Yadav (2013 18 ). Fluoride (F-)-The presence of high concentrations of fluoride in water is also a significant problem in the area.…”

Self-penetrating and interpenetrating 3D metal–organic frameworks constructed from 4-(4-carboxyphenoxy)-phthalic acid and N-donor auxiliary ligands

“…14). The main emission peaks of H 3 L, bbi were observed at 349 nm (λ ex = 280 nm) and 443 nm (Niu et al, 2012), respectively, which can be attributed to the π*→n or π*→π transitions (Zhang et al, 2003;Chen et al, 2008;Yadavi et al, 2013). On the complexation of these ligands with the Cd(II) atom, the emission peaks occurred at 414 nm and 468 nm (λ ex = 280 nm).…”

Green hydrothermal synthesis yields perylenebisimide–SiO2 hybrid materials with solution-like fluorescence and photoredox activity

“…One of the already early on heavily studied classes of hybrids were organic colorants, i.e., dyes or pigments, ‡ embedded in metal oxides, M x O y , as the inorganic component. 3 Such organic dye@M x O y HMs combine the optoelectronic properties contributed by the dyes with, e.g., high thermomechanical stabilities of the M x O y s. This improves the chemical, photochemical and thermal stability of the dyes, [4][5][6][7][8][9][10] and generates promise for a wide range of applications, such as photovoltaic cells and articial light harvesting, 11 photocatalysis, 12 ne chemical production, 13 optical sensors, 14 therapeutics carriers, 15 or smart textiles. 16 Synthetically speaking, the generation of dyes@M x O y , and of organic-inorganic HMs in general, bears one major challenge: the two components can hardly be synthesized and linked concomitantly, as they each require fundamentally different ways of preparation.…”

“…3 Such organic dye@M x O y HMs combine the optoelectronic properties contributed by the dyes with, e.g. , high thermomechanical stabilities of the M x O y s. This improves the chemical, photochemical and thermal stability of the dyes, 4–10 and generates promise for a wide range of applications, such as photovoltaic cells and artificial light harvesting, 11 photocatalysis, 12 fine chemical production, 13 optical sensors, 14 therapeutics carriers, 15 or smart textiles. 16…”