Study of host-guest interaction in mixed molecular crystals

✍ Scribed by M.K. Chaudhuri

• Publisher: Elsevier Science
• Year: 1974
• Tongue: English
• Weight: 566 KB
• Volume: 26
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(74)80418-5

✦ Synopsis

The measurement of the polarization ratio (PR) of guest transitions in mixed molecular crystals has been used as a tool to study the effect of host-guest interaction. Two mixed crystnl systems, namely naphthacene in transstllbene and anthracene in carbazole, have been studied. In the former system, the lowest energy host and guest transitions are oppositely polarized. It has been observed that in this system the @:a) PR value for the guest absorp tion system decreases progressively for the higher members of the vibronic bands as their energy difference. from the host excited state decreases. This result quite wnvincingly demonstrates the effect of the host on a guest transition. In the latter system, the-lowest energy host and guest transitions are polarized in the same direction, and in this system the (bzz) PR value has been found to be more or less constant over the entire guest absorption band system. The results of the polarization measurement in these two mixed crystals are in conformity with the theory of hostguest interaction developed by Craig and Thirunamachandran.