Ultraviolet spectroscopy charge transfer

Charge-transfer complex Visible and ultraviolet spectroscopy 1/1 ... 

Many surfactants, e.g. benzenesulphonates, contain aryl groups and it is found that they will form charge-transfer complexes with 1,2,4,5-tetracyano-benzene which can be detected by ultraviolet absorption and fluorescence spectroscopy (Masuhara et al., 1979) a similar result was obtained with an amphiphatic system. Fluorescence quenching in such micelles has been studied, an example being the quenching of the fluorescence of benzyl anthroate by triethylamine in Triton X (Costa and Macanita, 1978). 

Up to now, infrared spectroscopy has been used mainly to determine the types of hydroxyl groups and the acidity of zeolites (39). The frequencies of the vertical and horizontal vibrations (with respect to the cavity wall) of H2O molecules adsorbed in zeolite A were determined by measurements in the far infrared ( 220 and —75 cm" ) (37). These values are in agreement with a simple theoretical model. A number of ultraviolet and ESR studies are reviewed (33). The difference has been established between the specific molecular interaction of aromatic molecules on zeolites cationized with alkali cations and the more complex interactions involving charge transfer in CaX and deca-tionized X and Y zeolites. These more complex interactions with CaX zeolites containing protonized vacancies and with decationized zeolites are similar. These phenomena are related to the interactions of molecules with acidic centers in zeolites which are stronger, as compared with the molecular adsorption. 

Diffuse reflectance (DR) spectroscopy of Co permits the observation of d-d transitions in the near infrared and visible region and charge transfer (CT) transitions in the ultraviolet region. Co is the only common d ion and because of its stereochemistry the respective... 

Recently, the VL shift of 0.6 eV has been measured by means of ultraviolet photoemission spectroscopy (UPS) at the interface between tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ) [2]. This is one of the largest values for organic/organic interfaces studied so far. Calculations on TTF/TCNQ dimer showed a marked dependence of the charge transfer between two molecules with respect to their mutual geometry, as it is demonstrated in Fig. 1. 

UV-vis(-NIR) Ultraviolet-visible(-near-infrared) spectroscopy Electron and charge transfer transitions... 

The substitution of Ce in Ce02 by Hf results in the formation of ceria-hafnia solid solutions, whose properties in soot oxidation were investigated by Reddy et The order of soot oxidation activity (Ce-Hf > Ce-Zr) was correlated to the number of oxygen vacancy defects as evidenced by Raman studies. Moreover, diffuse reflectance ultraviolet-vis spectroscopy patterns showed that the ceria-hafnia sample had the best resolved band at about 255 nm, which has been characterized as a Ce <— 0 charge transfer transition and correlated to a higher concentration of oxygen vacancy defects. In a recent paper the same group also compared the catalytic activity of pure ceria, ceria-zirconia and ceria-lanthana solid... 

Abstract Far-ultraviolet (FUV) absorption spectroscopy provides molecular information about valence electronic transitions a, n, and Jt electron excitation and charge transfer (CT). FUV spectral measurements of liquid water and aqueous solutions had been limited, because the absorptivity of liquid water is very intense (absorptivity 10 cm at 150 nm). We have developed an attenuated total reflection (ATR)-type FUV spectrophotometer in order to measure FUV spectra of liquid water and aqueous solutions. The ATR-FUV spectroscopy reveals the features of the valence electronic transition of liquid water. This chapter introduces a brief overview of the first electronic transition (A. Y) of liquid water (Sect. 4.1) and the FUV spectral analyses (140-300 nm) of various aqueous solutions including how the hydrogen bonding interaction of liquid water affects the A <— X transition of water molecules (Sect. 4.1) how the A Y bands of water molecules in Groups 1, 11, xm, and lanthanoid (Ln +) electrolyte solutions are associated with the hydration states of the metal cations (Sects. 4.2 and 4.3) how the protonation states of amino acids in aqueous solutions affect the electronic transition of the amino acids (Sect. 4.4) and the analysis of O3 pulse-photolytic reaction in aqueous solution using a nanosecond pump-probe transient FUV spectrophotometer (Sect. 4.5). 

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