252960-45-5Relevant academic research and scientific papers
Emission from regioisomeric bis(phenylethynyl)benzenes during pulse radiolysis
Samori, Shingo,Tojo, Sachiko,Fujitsuka, Mamoru,Ryhding, Torben,Fix, Aaron G.,Armstrong, Brittany M.,Haley, Michael M.,Majima, Tetsuro
supporting information; experimental part, p. 3776 - 3782 (2009/09/29)
(Chemical Equation Presented) Emission from charge recombination between radical cations and anions of a series of regioisomeric 1,4-, 1,3-, and 1,2-bis(phenylethynyl)benzenes (bPEBs) substituted by various electron donor and/or acceptor groups was measured during pulse radiolysis in benzene (Bz). The formation of bPEB in the excited singlet state (1bPEB*) can be attributed to the charge recombination between bPEB?+ and bPEB?-, which are initially generated from the radiolytic reaction. This mechanism is reasonably explained by the relationship between the annihilation enthalpy change (-ΔH° ) for the charge recombination of bPEB?+ and bPEB?+ and excitation energy of 1bPEB*. Since the degree of the π-conjugation in the S 1 state and HOMO-LUMO levels of bPEB change with the substitution pattern of phenylacetylene groups on the central benzene ring and the various kinds of donor and/or acceptor group, the fine-tuning of the emission color and intensity of bPEB can be easily carried out during pulse radiolysis in Bz. For donor-acceptor-substituted bPEB, it was found that the difference in the charge transfer conjugated pathways between donor and acceptor substituents (linear-, cross-, and bent-conjugated pathways) strongly influenced the HOMO-LUMO energy gap.
