Adiabatic photodissociation of acenaphthylene dimers in the excited singlet state

✍ Scribed by Sadaaki Yamamoto; Mikio Hoshino; Masashi Imamura

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 449 KB
• Volume: 98
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(83)80254-1

✦ Synopsis

Ruorescencc spectroscopic studies of ncenaphthylene dimers in saturated hydrocarbon solutions have revealed that the dimer (AZ) photodissociates to the monomers (A) through the pathways AZ -I,,, IA: -IA* t-IA + 2 IA. Using the temperature dependence of *AZ and lA* emission intensities, the dissociation mechanism is discussed. l_ Introduction 2. Experimental Adiabatic photoreactions involving carbon-carbon bond cleavage and formation have been current subjects of photochemistry [l-7 1. Among these reactions, the photodissociation of aromatic photodimers has been investigated for understanding the reaction mechanisms and the radiationless transition processes of the electronically excited photodimers [7] _ These studies provide information for the theoretical consideration of the potential surface of photoreactions. Purified c-A2 and t-A2 were kindly donated by Mr. T_ Kowata. Acenaphthylene (E-P. grade) purchased from Tokyo Kasei was recrystallized twice from nhexane solution and then passed through a silica-gel column using ,z-hexane as elutant. Naphthalene purchased from Wako Pure Chemical Inc. was sublimed once under vacuum. Methylcyclohexane (MCH) and isopentane (IP) were purified by column chromatography on silica-gel and alumina [lo] _ In this connection we were interested in the photodissociation of the cis-and trans-acenaphthylene photodimers (c-AZ and f-A&