• Polymer(Korea)
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• v.31 no.2
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• pp.136-140
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• 2007

Charge transfer interaction as a hybridization mechanism of silsesquioxane/polymer was tested using carbazole (electron donor) group and dinitrobenzene (electron acceptor) group. Hybridization test was conducted using films made from mixing/casting of poly (carbazole-styrene) (PS/D) and dimtrobenzyl silsesquioxane (Cube/A), and transparent hybrid films were successfully obtained under some conditions. $^1H-NMR$ of PS/D and Cube/A, and W absorption test of hybrid films showed that one acceptor and one donor can form one charge transfer complex when no silsesquioxane molecule was included in films, but transparent hybrids with no phase separation were obtained only at acceptor/donor ratios less than 0.7 : 1. These results also suggested that on average 4 charge transfer complexes form per one silsesquioxane.

• Journal of the Korean Chemical Society
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• v.29 no.4
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• pp.372-381
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• 1985

Oxo molybdenum (V) complexes of substituted 8-quinolinols were synthesized and characterized by means of the investigation of elemental analysis, infrared spectra, electron spectra, electric conductivity and mass spectrometry compared with oxo molybdenum (VI) complexes. Oxo molybdenum(V) complexes were nonelectrolyte and one strong band of stretching mode of molybdenum and terminal oxygen appeared approximately $940cm^{-1}$. Oxo molybdenum(VI) complexes gave two peaks corresponding molybdenum containing ions, a molecular ion (I) of a 2 : 1 (ligand : metal) chelate and a fragment ion (II) of a 1:1 chelate due to the loss of ligand radical from ion (I). Molybdenum(V) complexes were observed the fragment ion(II) of a 1 : 1 chelate partly. The electronic spectra corresponding to d-d transition and charge transfer transition were observed and interpreted.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.453-459
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• 2013

In phtosynthetic light harvesting complexes, the electronic transition energies of chlorophylls are influenced by the Coulombic interaction with nearby molecules. Variation of the interactions caused by structural inhomogeneity in biological environment results in a distribution of disordered electronic transition energies of chlorophylls. In order to provide a practical guide to predict qualitative tendency of such distribution, we model four porphyrin derivatives including chlorophyll a molecule interacting with an external positive charge and calculate their transition energies using the time dependent density functional method. It is found that ${\pi}-{\pi}^*$ transition energies of the molecules are generally blue-shifted by the charge because this stabilizes occupied molecular orbitals to a greater extent than unoccupied ones. Furthermore, new transitions in the visible region emerge as a result of the red-shift in energy of an unoccupied Mg orbital and it is suggested that light-induced electron transfer may occur from the tetrapyrrole ring to the central magnesium when the molecules are interacting with a positive charge.

• Journal of the Korean Chemical Society
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• v.17 no.2
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• pp.85-94
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• 1973

The stability constants of the charge-transfer complexes formed between three derivatives of nitrobenzene, i.e., 1,3,5-trinitrobenzene, m-dinitrobenzene, nitrobenzene and eleven organic molecules such as $\alpha-picoline$, pyridine, dimethylsulfoxide, N, N'-dimethylacetamide, tetrahydrofurane, 1, 4-dioxane, diethyl ether, acetonitrile, propylene oxide, epichlorohydrine, and methyl acetate, have been determined by ultraviolet absorption spectroscopy in carbon tetrachloride solution at 25.0$^{\circ}C$. The parameters of the electrostatic effect ($E_D$) and covalent effect ($C_D$) for the eleven organic compounds have been calculated from the modified equation of the double-scale enthalpy,$logK = E_AC_A+E_DC_D$ and also the shift of C=O vibrational frequency in infrared spectra for N,N'-dimethylacetamide have been measured from the solutions of above organic compounds. The empirical equation, ${\Delta}{\nu}_{C=O} = 37.4-5.47E_D+12.1C_D$, related to the parameters and the frequency shift has been derived. It seems that the stabilities of the complexes principally depend on the covalent effect. Especially it is found that $\pi$ orbitals in molecules, in addition to the parameters, play the important role in forming the charge-transfer complexes.

• Analytical Science and Technology
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• v.8 no.4
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• pp.481-486
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• 1995

Quenching experiments by photoinduced electron transfer between a charged donor and a neutral acceptor were carried out in acetonitrile, dichloromethane and mixed solvents of acetonitrile and dichloromethane. Tris(2, 2'-bipyridine) ruthenium(II) ($[Ru(bpy)_3]^{2+}$) which has 2+ charge and dicyanobis (2, 2'-bipyridine) ruthenium(II) ($Ru(bpy)_2(CN)_2$) which has no charge were used as electron donors, and a series of tris(${\beta}$-diketonato) ruthenium (III) was used as acceptor. In dichloromethane, $[Ru(bpy)_3]^{2+}$ and its counter ions ($ClO{_4}^-$) form ion pair. In the estimate of ${\Delta}G$ of electron transfer, the electrostatic potential between counter ions and product ion pair produced by electron transfer must be taken into account. A similar effect of counter ions was found in mixed solvents of 10, 30, 50, 70 and 90% acetonitrile ratio in volume. The effect of counter ion on ${\Delta}G$ became smaller with the increase in acetonitrile ratio. The result in mixed solvents suggests that $[Ru(bpy)_3]^{2+}$ and its counter ions form ion pair even in 90% acetonitrile solution.

• Journal of the Korean Chemical Society
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• v.29 no.5
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• pp.482-489
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• 1985

The substituted quinolinium salts of pentachlorooxomolybdate (V) have been synthesized and characterized by means of the investigation of elemental analysis, infrared spectra, electron spectra, electric conductivity. The results of elemental analysis were well coincided with the theoretical value and all prepared salts were mononuclear complexes. The complexes were binary univalent electrolytes and analyzed d-d transition and charge transfer transition.

• Journal of the Korean Chemical Society
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• v.15 no.6
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• pp.352-358
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• 1971

The interaction between dimethylsulfoxide molecules and some organic molecules, i.e.nitrobenzene, m-dinitrobenzene, o-dinitrobenzene, 1,3,5-trinitrobenzene, m-xylene, mesitylene, bibenzyl, biphenyl, o-phenanthrene, naphthalene, has been studied. The organic molecules exhibit negative deviation from Raoult's law due to the formation of the charge transfer complexes with dimethylsulfoxide. The stability constants of the complexes were determined spectrophotometrically, and also some thermodynamic functions were calculated. The binding energies of the complexes appear in the range of -1 ∼ -4 kcal/mole. The stability depends on the polarity and basicity of the solvent used.

• Journal of the Korean Chemical Society
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• v.25 no.3
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• pp.177-182
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• 1981

Benzoylpyridinium and lutidinium salts containing$ [MoO(NCS)_5]^{2-}$ have been synthesized. The complexes have been characterized by spectroscopic, magnetic susceptibility and conductivity studies. Benzoylpyridinium and lutidinium oxopentaisothiocyanatomolybdates(Ⅴ) arise from d-d and charge transfer transitions. The magnetic moments of the complexes are close to the spin-only values. The complex anions are mononuclear containing N-bonded $NCS^-$ ligand.

• Bulletin of the Korean Chemical Society
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• v.1 no.2
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• pp.62-68
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• 1980

Ultraviolet spectrophotometric investigations have been carried out the systems of monoalkylbenzene with iodine in carbon tetrachloride. The results reveal the formation of one to one molecular complexes. The equilibrium constants for these complexes of representative monosubstituted benzene reveal the following order of increasing stability: benzene < methyl- < ethyl- < n-propyl-benzene. The value of ${\Delta}H$, ${\Delta}G$, and ${\Delta}S$ for interaction of a number of monoalkyl substituted benzene with iodine has been determinated. In general, as ΛH becomes increasingly negative, corresponding decreases in ${\Delta}G$ and ${\Delta}S$ values are observed, and these variation are linear. The thermodynamic constants become increasingly negative with increasing monoalkyl substitution of the aromatic donor nucleus. The complex bond is therefore weak, and its formation is accompanied by relatively small entropy changes.

• Textile Coloration and Finishing
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• v.4 no.1
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• pp.21-25
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• 1992

The charge-transfer(CT) complexes derived from various donors and acceptors were evaluated as coloring matter. Dyes absorbing light in the region from the visible to the near-infrared wavelengths were synthesized. In order to determine the molar ratio of the donor to the acceptor in the CT complex in the solution, the continuous variational method was applied to each system. A 1:1 correspondence between the donor and the acceptor molecules in the CT complex in the solution is established. Color development properties in paper were examined. The longer the exposure time at constant temperature, the deeper the strength of color in paper. The strength of color at high temperature was decreased, because sublimed CT dyes in paper were migrated out side of paper.