Handbook of Solvents - George Wypych - ChemTech - Ventech!

11.1 Theoretical treatment of solvent effects 661
Table 11.1.3. INDO/S SCRF CI calculated and experimental spectroscopic transition
energies of some dyes in different solvents 27
Molecule Solvent νcalc, cm -1
(Scheme 23)
(Scheme 24)
(Scheme 25)
Gas phase
Cyclohexane
Water
Gas phase
n-Hexane
Water
Gas phase
Chloroform
Water
Scheme 23 Scheme 24
Scheme 25
29,700
26,300
22,500
36,900
34,800
31,100
20,200
21,800
24,600
νexp, cm -1
-
27,400
23,300
-
30,200
26,100
-
19,600
22,100
The INDO/S SCRF CI method has been also successfully applied for the prediction of
the solvatochromic shifts in various nitro-substituted porphyrins. 32
The SCRF methodology has been employed also for the prediction of the
solvatochromic shifts on emission spectra. 33,34 A satisfactory agreement was obtained between
the calculated and experimental fluorescence energies of
p-N,N-dimethylaminobenzonitrile in different solvents. Finally, the solvent-induced shifts
in the vibrational spectra of molecules have been also calculated using the SCRF theory. 35
The SCRF approach has been also implemented for the treatment of solute-continuum
solvent systems at the ab initio Hartree-Fock level of theory. 36,37 In addition, a general SCRF
(GSCRF) approach has been proposed to account for the interaction of the solvent reaction
field with the arbitrary charge distribution of the solute molecule. According to this theory,
38,39 the effective Hamiltonian of the solute in the solvent has the following form
⎣ ⎦
H� H� 0 0
= + drΩ r V r + dr′ G r,r′ Ω r′
[11.1.71]
∫
() () ∫ ( ) ( )
s s s m s
where Ω s ( r) is the solute charge density operator given by
() r =− ( r − r) + ∑Z
( r −R
)
Ωs i a a
i
a
∑δ δ [11.1.72]