Charge-transfer exciton transitions in anthracene-PMDA crystal

✍ Scribed by A. Brillante; M.R. Philpott; D. Haarer

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 261 KB
• Volume: 56
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(78)80225-5

✦ Synopsis

The reflection spectrum of the fust singlet charge transfer transition of anthracene-PMDA (pyromeflitic dianhydride) crystal has been obt.dned at temperatures close to 2 K. The spectrum is polarized along the stack axis and consists of a series of vrbronic bands, approximately 500 cm-l wide, with impressed fme structure arising from intermolecular phonon modes. This fme structure is particuiarIy prominent for the O-O band which starts with a zero-phonon line which is the most dominant feature of the entire spectrum-The zero-phonon line has a reflectivity of appro.ximately 0.37 and a iine width less than 5 cm-'. This is the fust time that an absolute reflection spectrum of a charge transfer transition with such vibronic details has been obtained. A preliminary discussion of the nature of the transition is presented.