Raman investigation of protonation of DR1 molecules in silica or ORMOSILs matrices by the sol-gel technique

Abstract

The chemical properties of Disperse Red 1 (DR1), a dye molecule commonly used as an active guest of thin silica or ORMOSILs films for optical applications, were investigated by micro‐Raman spectroscopy. The influence of the acid catalyst was studied in DR1 + TEOS (tetraethyl orthosilicate), DR1 + TEOS + GLYMO (3‐glycidoxypropyltrimethoxysilane) and DR1 + TEOS + ICPTEOS [3‐(triethoxysilyl)propyl isocyanate] sol–gel starting solutions and on the corresponding bulk glasses. A protonated form of DR1 was found in some glasses, and its Raman spectrum is reported. The protonation is not observed in GLYMO‐based matrices owing to the protection against acid attack provided by the epoxy group. Copyright © 2000 John Wiley & Sons, Ltd.

Environment-Dependent Ultrafast Photoisomerization Dynamics in Azo Dye

“…19,24,25 Fourier transform of the time trace measured at 626 nm (see Figure 4a) was calculated as shown in Figure 4b. It agrees with Raman spectrum, 26 confirming that the oscillations in the time-resolved trace are caused by molecular vibrations.…”

“…Fourier transform of the time trace measured at 626 nm (see Figure a) was also calculated for DR19 in a film sample as shown in Figure b. It agrees with the result obtained for solution sample (see Figure b) and Raman spectrum . The LP-SVD analysis was performed for the time trace of the film sample.…”

“…When the obtained parameters were used, the time trace was reconstructed, as shown in Figure a, agreeing with the measured time trace. The vibration modes of 1100, 1131, and 1330 cm –1 are assigned to Φ–N stretching, C–H deformation, and NO 2 symmetric stretching modes, respectively, referring to the Raman study . The result of the LP-SVD analysis shows that the C–H deformation has distinctly high amplitude and fast lifetime among these three vibration modes.…”

“…The vibration modes of 1100, 1131, and 1330 cm À1 are assigned to ΦÀN stretching, CÀH deformation, and NO 2 symmetric stretching modes, respectively, referring to the Raman study. 26 The result of the LP-SVD analysis shows that the CÀH deformation has distinctly high amplitude and fast lifetime among these three vibration modes. It reflects that photoisomerization of the DR19 in solution causes large deformation around the CÀH bond in its primary process.…”

Functionalization of Single-Wall Carbon Nanotubes with Chromophores of Opposite Internal Dipole Orientation

“…The former peak is attributed to C-N (NO) stretching vibration and the latter is related to the N-O stretching mode. 32 Figure 2e shows the Raman spectra of the pristine SWNTs and those functionalized with DR1P and DR1P'. Weak but distinct Raman signals of DR1P and DR1P' were detected in the functionalized SWNTs.…”