Interaction of electron acceptors with bases. Part 4.—Effect of solvent on π–π intermolecular charge-transfer complexes

Electron donor properties and catalytic activity of manganese ferrospinels

“…The reflectance spectra of the samples after adsorption of the EA showed bands appearing below 400 nm corresponding to physically adsorbed state of neutral TCNQ and a band near 600 nm [17] which was attributed to dimeric TCNQ radical which absorbs at 643 nm. A broad band extending up to 700 nm corresponds to chloranil anion radical [18]. The samples after TCNQ adsorption gave unresolved ESR spectra with a g value of 2.003, while those after chloranil adsorption gave unresolved ESR spectra with a g value of2.011, which are in agreement with those reported earlier.…”

Spectroscopic studies of charge transfer complexes of meso‐tetra‐p‐tolylporphyrin and its zinc complex with some aromatic nitro acceptors in different organic solvents

“…16,22 Therefore, the difference of the dipole moment between ground and excited states is smaller for a stronger complex than for a weak one. The red shift of the CT band caused by polarity change on going from CCl 4 to CH 2 Cl 2 is smaller in stronger complexes than in weak ones since the solvent stabilization energy difference at ground and CT excited is smaller for a strong complex than for a weak complex.…”

Spectrophotometric and fluorescence quenching studies of the charge transfer complexation of (4-dimethylamino-benzylidene)-(4,6-dimethyl-pyrimidin-2-yl)-amine with some organic acceptors

“…This increase in K CT value with decreasing solvent polarity may be due to the fact that, the dative structure (D + -A − ) should be stabilized in a less polar solvent. Dissociation of the complexes into D + and A − radicals has been found to occur in the ground state [39].…”