Ring opening process of some spirochromenes by photoproduced HCl in poly(N-vinyl carbazole)

Abstract

The coloration reaction of some spirochromenes (SP) has been investigated in the case of a free radical photosensitive system composed of a poly(N‐vinylcarbazole) matrix (PVCz) in dichloromethane containing carbon tetrachloride as an activator at average ratios of 5:1:0.1 for PVCz, CCl4 and SP, respectively. In this system, photoproduced HCl leads to the formation of the colored forms of SP. Acidification and irradiation of the variety of spirochromene solutions in the presence and absence of PVCz were also investigated and compared with the effect of photoproduced HCl on the reversibility of the ring opening process. The opened forms of the compounds were characterized by UV–visible spectra, pH and conductivity measurements. The effect of solvent and the substituent of SP were investigated. Decoloration reactions of the opened forms of SP at 50°C were followed using UV–visible spectroscopy, pH and conductivity measurements. © 1997 John Wiley & Sons, Ltd.

Matrix effect on the electrochromism of spirochromics

“…These experiments show that PMMA acts as a matrix for spirooxazine type molecules (SP 3 and SP 4 ) without reducing the photochromic activities of these compounds, whereas PVCz (as previously reported) is a more suitable binder for SP 1 , SP 2 and SP 7 [4].…”

“…The nature of the polymer used also effects the bleaching process. For example, the use of a polyvinylcarbazole (PVCz) matrix results in a reversible bleaching process without reducing the photochromic activity of certain samples [4]. 10, 164±168 (1999) model Potentiostat interfaced to a PC and a Kipp and Zonen XY recorder were used for the electrochemical process.…”

Synthesis, Characterization, In‐Vitro and In‐Vivo Anti‐Cancer Evaluation of Novel Benzopyrylium Salts on Colorectal Cancer Model of Drosophila Melanogaster

“…Additionally, pyrylium salts are employed as constituent dyes in lasers [6] and have been the subject of research regarding their photochromic properties. [7][8][9][10] With the advent of photodynamic therapy, pyrylium salts have also been explored for their biological activities. It has been reported that thiopyrylium dye inhibits proliferation of human colon carcinoma cell line CX1.…”

Design and Study of a Photo-Switchable Polymeric System in the Presence of ZnS Nanoparticles under the Influence of UV Light Irradiation

“…The exploration of such light-responsive molecules in devices typically requires immobilization on the surface through an appended functionality that does not interfere with the light switching behavior. This has been achieved for photo-switchable molecules using formations of self-assembled monolayers (SAMs) [ 39 , 40 , 41 , 42 ], bilayers [ 43 , 44 , 45 ] and incorporation into polymer films [ 46 , 47 , 48 , 49 ], beads and nanoparticles [ 50 , 51 , 52 ]. Furthermore, the polymerization process itself must be compatible with the photo/electroactive switching units, and in addition, the incorporation of the photoresponsive functionality must not affect the polymerization.…”