Absorption spectra in solution

Bayliss, N.S. 1950. The effect of the electrostatic polarization of the solvent on the electronic absorption spectra in solution. J. Chem. Phys. 18 292-296. 

Traces of phosphorus, silicon, and arsenic can be determined colorimetrically by complexing with molybdate and reducing the heteropoly anion to a very deep blue color. Absorption spectra in solution of heteropoly blues show charge transfer bands in the visible region with molar extinction coefficients of the order 104 to 10s 123 ... 

Carnall, w. T. and Fields, P. R., Lanthanide and Actinide Absorption Spectra in Solutions Advances in Chemistry Series, Vol. 71, Fields, P. R. and Moeller, T., Symposium Chairmen, American Chemical Society, Washington, D.C., 1967. 

Values obtained from absorption spectra in solution (293 K). 

Ultraviolet (UV) and visible spectra, also known as electronic spectra, involve transitions between different electronic states. The electronic transition is accompanied by the vibrational and rotational transitions so that what woidd otherwise be an absorption line becomes a broad peak containing vibrational and rotational fine structure. Furthermore, the molecular interaction between solute and solvent levels it to a smooth curve (envelope) for the absorption spectra in solutions. The accessible regions are 200-400nm for... 

Lanthanide and Actinide Absorption Spectra in Solution, W.T. Carnall and PR. Fields, In Lanthanide/Actinide Chemistry, Advances in Chemistry Series No. 71, PR. Fields and T. Moeller (Eds.), Am. Chem. Soc Washington, DC, 1967, pp. 86-101. 

After 1865, narrow absorption bands played a role for evaluating the separation of two elements, as elaborated by Auer von Welsbach, and Soret (who was professor of physics at the University of Geneva, where Marignac was professor of chemistry and mineralogy) ascribed some absorption bands prominent in some erbium fractions to a new element. A few years after, these bands turned out to occur in holmium, separated by Cleve in 1879. There are minor chemical effects in sulfate complexes, mixed anion-hydroxo complexes, etc., on absorption spectra in solution. 

A scheme for the treatment of the solvent effects on the electronic absorption spectra in solution had been proposed in the framework of the electrostatic SCRF model and quantum chemical configuration interaction (Cl) method. Within this approach, the absorption of the light by chromophoric molecules was considered as an instantaneous process. Tliere-fore, during the photon absorption no change in the solvent orientational polarization was expected. Only the electronic polarization of solvent would respond to the changed electron density of the solute molecule in its excited (Franck-Condon) state. Consequently, the solvent orientation for the excited state remains the same as it was for the ground state, the solvent electronic polarization, however, must reflect the excited state dipole and other electric moments of the molecule. Considering the SCRF Hamiltonian... 

N. S. Bayliss, J. Chem, Phys., 18, 292 (1950). The Effect of the Electrostatic Polarization of the Solvent on Electronic Absorption Spectra in Solution. 

This results in having the conduction pathway transmitted through the bridging moietigg. Porphyrin-ligand charge transfer processes have also been identified by elec onic absorption spectra in solution as in the case of (pyridine)2Fe tetraphenylporphyrin. 

RARE EARTH IONS IN SOLUTION 2. Absorption spectra in solution... 

Charge transfer takes place not only in electrode processes but also in numerous homogeneous chemical reactions, and above all in redox reactions. The approach worked out by Gurney is applicable in this case too, since the transfer of an electron from the reducing agent A to the oxidizer B takes place at the moment when the energy levels of the initial (A + B ) and the final (A + B ) states are equalized. This equalization takes place as a result of fluctuations of the medium. These ideas in a qualitative form and without a direct relation to Gurney s theory were formulated by Libby[190], who proceeded from Franck s ideas on photochemical processes and absorption spectra in solutions. In the most complete form, these concepts were formulated approximately at the same time in the well-known paper by Platzmann and Franck[191] (see also [192]). Similar... 

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