35398-30-2Relevant academic research and scientific papers
Photodissociation of Hexaarylbiimidazole. 1. Triplet-State Formation
Qin, X.-Z.,Liu, A.,Trifunac, A. D.,Krongauz, V. V.
, p. 5822 - 5826 (1991)
The mechanism of photodissociation of 2-chlorohexaarylbiimidazole is studied by laser flash photolysis in organic liquids and by EPR methods in polymer and low-molecular-weight organic matrices.It is found that at low temperature (ca. 10 K) the ultraviolet irradiation produces a triplet hexaarylbiimidazole rather than the radicals.No triplet-state decomposition into radicals is observed, supporting the results of indirect measurements reported by other researchers.At higher temperatures, the radicals formed from the dissociation of the singlet state dominate.This is the first direct observation of the hexaarylbiimidazole triplet reported to date.The results are explained by considering the molecular structure and hexaarylbiimidazole mobility.
In situ Observation of Molecular Swapping in a Crystal by X-ray Analysis
Kawano, Masaki,Sano, Tomokatsu,Abe, Jiro,Ohashi, Yuji
, p. 1372 - 1373 (2007/10/03)
X-ray diffraction analysis elucidated that a pair of hexaarylbiimidazoles was transformed to a complex composed of two lophyl radicals and a piezodimer on irradiation at low temperatures. The piezodimer, the existence of which has been assumed spectroscopically as an unstable isomer, was produced via molecular swapping of two photo-induced lophyl radicals with drastic conformational change. The black crystal reverted to the original structure on warming to 25 deg C.
