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Complexation of 4‐dimethylaminoazobenzene with various kinds of cyclodextrins: Effects of cyclodextrins on the thermal cis‐to‐trans isomerization
Author(s) -
Sueishi Yoshimi,
Hishikawa Hiroaki
Publication year - 2002
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.10074
Subject(s) - chemistry , isomerization , cyclodextrin , dimethyl sulfoxide , methanol , circular dichroism , photochemistry , medicinal chemistry , stereochemistry , organic chemistry , catalysis
Abstract On the basis of the change in electronic and induced circular dichroism spectra for complex formation, the complexation of 4‐dimethylaminoazobenzene (DAAB) with four kinds of cyclodextrins (α‐ and β‐cyclodextrin (CD), heptakis(2,6‐di‐ O ‐methyl)‐β‐cyclodextrin, and heptakis(2,3,6‐tri‐ O ‐methyl)‐β‐cyclodextrin) was studied in methanol–water and dimethyl sulfoxide–water mixtures. It was found that the trans and cis isomers of DAAB form two different types of complex (inclusion and lid type) with CDs, depending on the kinds of CDs and solvents. Further, we have examined the effect of CDs on the thermal cis‐to‐trans isomerization of DAAB. The accelerated or decelerated effect on the thermal isomerization was observed upon adding CDs. The effects of CDs on the thermal isomerization are discussed in connection with the complexation of the cis‐isomer of DAAB with CDs. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 481–487, 2002