Charge-Transfer Probes for Molecular Recognition via Steric Hindrance in Donor-Acceptor Pairs

Document Type

Article

Language

eng

Publication Date

1997

Publisher

American Chemical Society

Source Publication

Journal of the American Chemical Society

Source ISSN

0002-7863

Original Item ID

DOI: 10.1021/ja9720319

Abstract

Molecular association of various aromatic hydrocarbons (D, including sterically hindered donors) with a representative group of diverse acceptors (A = quinone, trinitrobenzene, tetracyanoethylene, tropylium, tetranitromethane, and nitrosonium) is visually apparent in solution by the spontaneous appearance of distinctive colors. Spectral (UV−vis) analyses of the colored solutions reveal their charge-transfer origin (λCT), and they provide quantitative information of the intermolecular association in the form of the KDA and εCT values for the formation and visualization, respectively, of different [D,A] complexes. Importantly, such measurements establish charge-transfer absorption to be a sensitive analytical tool for evaluating the steric inhibition of donor−acceptor association. For example, the steric differences among various hindered aromatic donors in their association with quinone are readily dramatized in their distinctive charge-transfer (color) absorptions and verified by X-ray crystallography of the charge-transfer crystals and/or QUANTA molecular modeling calculations of optimum intermolecular separations allowed by van der Waals contacts.

Comments

Accepted version. Journal of the American Chemical Society, Vol. 119, No. 40 (1997): 9393-9404. DOI. © 1997 American Chemical Society. Used with permission.

Sergey V. Lindeman and Rajendra Rathore were affiliated with the University of Houston at the time of publication.

Link to Full Text

Share

COinS