MOLECULAR-COMPLEXES OF CROWN-ETHERS .2. COMPLEXES BETWEEN CROWN-ETHERS AND PI-ACCEPTORS

Citation
Gaw. Derwish et al., MOLECULAR-COMPLEXES OF CROWN-ETHERS .2. COMPLEXES BETWEEN CROWN-ETHERS AND PI-ACCEPTORS, Journal of inclusion phenomena and molecular recognition in chemistry, 20(2), 1994, pp. 123-129
Citations number
15
Categorie Soggetti
Chemistry,Crystallography
ISSN journal
09230750
Volume
20
Issue
2
Year of publication
1994
Pages
123 - 129
Database
ISI
SICI code
0923-0750(1994)20:2<123:MOC.CB>2.0.ZU;2-C
Abstract
The intermolecular charge transfer (CT) complexes of four crown ethers (CE), viz. B15C5, B18C6, DB18C6 and DB24C8 (as donors), and three acc epters, i.e. tetracyanoethylene (TCNE) 7,7,8,8-tetracyanoquinodimethan e (TCNQ) and chloranil were studied in the UV-Visible region in 1,2-di chloroethane (DCE) at 298.2 K. Solid complexes were also prepared and the ratio of the donor to the acceptor was 1 : 1. Results indicate tha t the lambda(max) of the CT band decreases while K-c (formation equili brium constant) increases following the systematic change of the elect ron affinity of the pi accepters. The K-c values suggest that the phen yl group in CE plays a major role in the formation of a CT complex.