Solvent effects on the resonance Raman spectra of bacteriochlorophyll a cation radical

✍ Scribed by Yasuhito Misono; Ei-ichi Nishizawa; Leenawaty Limantara; Yasushi Koyama; Koichi Itoh

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 587 KB
• Volume: 236
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)00237-x

✦ Synopsis

Resonance Raman (RR) spectra were measured for the cation radical of bacteriochlorophyli a in acetone, methanol, dichloromethane and mixed solvents of acetone and methanol. The ring-breathing (C~-C m stretching) frequency of the radical (abbreviated as v~ +) was observed at 1601 cm-i in acetone (forming a penta-coordinated monomer), at 1587 cmin methanol (forming a hexa-coordinated monomer) and at 1600 cm -~ in dichioromethane (forming a penta-coordinated aggregate). The RR spectrum of the radical in dichloromethane is almost identical to the transient RR spectrum ascribed to 'the aggregated T~ species of Bchi a' formed in the particular solvent by Nishizawa, Limantara, Nanjou, Nagae, Kakuno and Koyama, indicating that their interpretation needs to be revised.