Temperature dependence of electronic energy transfer and quenching in copolymer films of styrene and 2-(2'-hydroxy-5'-vinylphenyl)-2H-benzotriazole

New fluorescent monomers and polymers displaying an intramolecular proton-transfer mechanism in the electronically excited state (ESIPT), 1. Synthesis of benzazolylvinylene derivatives and its copolymerization with methyl methacrylate (MMA)

“…These new polymers containing the benzazole moiety combine the high thermal stability of rigidrod polymers with the photochemical stability and resistance to degradation by free radicals of intramolecular hydrogen bonded (IHB) moieties. The copolymer samples described in this paper confirm how the thermal stability of a polymer can be affected by introduction of dyes in the main-chain as previously reported by Scott et all 15) . We have observed a significant increase in the T di and T g values for the copolymers containing the dyes of the benzazole family when compared with the MMA polymer itself.…”

Theoretical Modelling for the Ground State Rotamerisation and Excited State Intramolecular Proton Transfer of 2-(2’-hydroxyphenyl)oxazole, 2-(2’-hydroxyphenyl)imidazole, 2-(2’-hydroxyphenyl)thiazole and Their Benzo Analogues

“…Equilibrium parameters of different photoisomers of HBO, HBI, HBT and HPO, HPI, HPT in different electronic states. R [7][8][9][10][11][12][13][14][15][16][17] represents the interatomic distance between the two atoms for the first series and R [8][9][10][11][12][13] represents it for the other series referred to by the numbers (see Scheme 1). T 7-8-10-11 is the torsional angle developed by the atoms of the first series and T 2-1-7-8 is that developed by those of the second series.…”

“…2.54  4.00 R [8][9][10][11][12][13] 2.14  1.00 normal and rotameric forms and thus rules out the independent existence of the rotamer. The instability of the rotamer of HBT has been supported by Nagaoka et al [44] from their ab initio calculations.…”

“…Studies range from the choice of a variety of homo-and heterocyclic aromatic molecular systems to a wide variety of pure and mixed homogeneous and microheterogeneous solvents [1][2][3][4][5][6][7][8][9][10][11]. This phenomenon has widespread implications in photostabilizers [12], laser dyes [13] and also in the biological fields [14]. In organic bifunctional molecules, containing both the hydrogen atom donor and acceptor groups in close proximity, an intramolecular hydrogen bond is generally formed in the ground electronic state [15].…”

Research of electronic absorption spectra of benzazols derivatives by ab initio calculations

“…Because of its immense potential, excited state intramolecular proton transfer has generated massive interest in recent years [3][4][5][6]. This phenomenon has widespread implications in photostabilizers [7], plastic scintillator, laser dyes [8] and also in the biological fields [9].…”