Grimshaw, James; Prasanna de Silva, A. published the artcile< Photocyclization of aryl halides. Part 4. 5-(2-Halophenyl)-1,3-diphenyl-Δ2-pyrazolines. Predissociation and electron transfer between intramolecular but separate chromophores>, Formula: C8H4BrNO, the main research area is pyrazoline halophenyl diphenyl photocyclization; halophenyldiphenylpyrazoline photochem ring closure; phenylpyrazoline halophenyl photocyclization.
Photoreaction of 5-(2-iodophenyl)-1,3-diphenyl-Δ2-pyrazoline (I) proceeds by simple bond homolysis from the S1° state to give 1,3,5-triphenylpyrazoline and 2-phenylpyrazolo[1,5-f]phenanthridine in a ratio which depends on the H atom donor ability of the hydrocarbon solvent. The quantum yield for decomposition of I depends on the viscosity of the hydrocarbon solvent and on the temperature The corresponding chloro and bromo compounds cyclize slowly and the 3-iodo- and 4-iodophenyl compounds are photostable. Consideration of these facts and the complementary fluorescence data suggests a mechanism of interchromophoric predissociation to an nσ* state. However, examples are given where there is a smaller electron donor-acceptor energy gap between the 2 chromophores so that photoreaction occurs by an electron transfer path.
Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) published new progress about Photocyclization. 89003-95-2 belongs to class bromides-buliding-blocks, and the molecular formula is C8H4BrNO, Formula: C8H4BrNO.
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary