E. Wagner-czauderna et Mk. Kalinowski, Visible absorption spectrum of benzophenone radical anion in dipolar aprotic solvents, COLL CZECH, 65(10), 2000, pp. 1573-1579
Citations number
18
Categorie Soggetti
Chemistry
Journal title
COLLECTION OF CZECHOSLOVAK CHEMICAL COMMUNICATIONS
Two-parameter regression including the acceptor number (AN) and permittivit
y (epsilon) of the solvent explains to some extent the solvatochromic shift
of the absorption band of benzophenone radical anion (Ph-2(C)over dot-O-)
in the visible region. In 11 dipolar aprotic solvents characterized by epsi
lon > 10, in which the Ph-2(C)over dot-O- anions are not associated with (C
2H5)(4)N+ cations (the radicals were prepared by cathodic reduction of benz
ophenone in the presence of (C2H5)(4)N+CLO4- as electrolyte) a correlation
equation has the form v(max) (in cm(-1)) = 86.2(AN) - 19.7 . 10(3)[(epsilon
- 1)/(2 epsilon + 1)] + 21.32 . 10(3). It reflects the relative stabilizat
ion of the ground state in a medium with a high acceptor number and an incr
ease in the dipole moment of Ph-2(C)over dot-O- during excitation.