QUANTITATIVE TREATMENT OF THE SOLVENT EFFECTS ON THE ELECTRONIC ABSORPTION AND FLUORESCENCE-SPECTRA OF ACRIDINES AND PHENAZINES - THE GROUND AND FIRST EXCITED SINGLET-STATE DIPOLE-MOMENTS
Jj. Aaron et al., QUANTITATIVE TREATMENT OF THE SOLVENT EFFECTS ON THE ELECTRONIC ABSORPTION AND FLUORESCENCE-SPECTRA OF ACRIDINES AND PHENAZINES - THE GROUND AND FIRST EXCITED SINGLET-STATE DIPOLE-MOMENTS, SPECT ACT A, 51(4), 1995, pp. 603-615
Electronic absorption and fluorescence excitation and emission spectra
of four acridines (acridine, Acridine Yellow, 9-aminoacridine and pro
flavine) and three phenazines (phenazine, neutral Red and safranine) a
re determined at room temperature (298 K) in several solvents of vario
us polarities (dioxane, chloroform, ethyl ether, ethyl acetate, 1-buta
nol, 2-propanol, ethanol, methanol, dimethylformamide, acetonitrile an
d dimethyl sulfoxide). The effect of the solvent upon the spectral cha
racteristics of the above compounds, is studied. In combination with t
he ground-state dipole moments of these compounds, the spectral data a
re used to evaluate their first excited singlet-state dipole moments b
y means of the solvatochromic shift method (Bakhshiev's and Kawski-Cha
mma-Viallet's correlations). The theoretical ground and excited single
t-stare dipole moments for acridines and phenazines are also calculate
d as a vector sum of the pi-component (obtained by the PPP method) and
the sigma-component (obtained from sigma-bond moments). For most acri
dines and phenazines under study, the experimental excited singlet-sta
te dipole moments are found to be higher than their ground state count
erpart. The application of the Kamlet-Abboud-Taft solvatochromic param
eters to the solvent effect on spectral properties of acridine and phe
nazine derivatives is discussed.