Visible spectroscopic studies

UV-visible spectroscopic studies of polymerization of Pu(IV) hydrolysis products. 233, 235-39... 

VO(acac)2 < VO(Et-acac)2 VO(Me-acac)2 BMOV. Conversion rates for all hydrolysis products were faster than for the original species. Both EPR and visible spectroscopic studies of solutions prepared for administration to diabetic rats ocumented both a salt effect on the species formed and formation of a new halogen-containing complex. The authors concluded that vanadium compound efficacy with respect to long-term lowering of plasma glucose levels in diabetic rats traced the concentration of the hydrolysis product in the administration solution. 

Satsuma, A., Shibata, J., Wada, A., Shinozaki, Y. and Hattori, T. (2003) In-situ UV-visible spectroscopic study for dynamic analysis of silver catalyst. Stud. Surf. Sci. Catal., 145, 235-238. 

A.R. Roudman and R.P. Kusy, Uv-visible spectroscopic study of the reaction kinetics of methylpiperadine-modified poly(vinyl chloride)s for use as fixed-state proton carrier membranes, Polymer, 1998, 39, 3641-3649. 

PdX(PR3)2(phen)]BF4 in hot methanol or CHjClj leads to the square planar complexes [PdX(PR3)(phen)]BF4. A u.v.-visible spectroscopic study of a range of related Pd" and Pt bipyridine complexes, including [PdCljfbipy)], has shown large shifts with change in solvent, which may be correlated with the Ej parameters of the solvents. Complexes of the ligand thiazolidine-2-thione... 

On the other hand UV-visible spectroscopic studies have revealed that the alkyl and hydride cations exist as THF adducts. The importance of elapsed time following MAO addition on the composition of the active species has also been investigated by UV-visible spectroscopy [127]. 

Hurst and coworkers synthesized an amphiphilic azobenzene derivative, 4-dodecy-4 -(3-phosphate-trimethyleneoxy)azobenzene (DPMA) and incorporated it into DHP vesicles. ions were entrapped in the vesicles during the vesicle formation. Photocontrolled release of ions across the vesicle membrane was conducted by monitoring the K ion concentration released into the solution under UV and visible light irradiation conditions. UV/visible spectroscopic studies confirmed that DPMA molecules were dispersed into the vesicle membrane without aggregation and isomerized reversibly in the vesicle membrane under UV and visible light irradiation. 

The desired polyimide derivatives were prepared by condensation polymerization as shown in Scheme 1. The initial polyamic acids (PAA 1-4) could be spun onto a substrate and cured by ramping the temperature to 260 C. For those examples where X=(CF3)2C, the polyimide derivatives were soluble in organic solvents. These materials were usually spun in the preimidized form. The improved thermal stability of the arylamino substituted chromophores tethered to the polyimide backbone is obvious from the DSC analysis. The onset decomposition temperature measured by DSC of the aryl substituted polymer PI-2b is almost 40°C hi er than that of Pl-lb (Td = 376 vs 338T). Likewise, this stabilizing effect is apparent variable temperature, UV-visible spectroscopic studies of the polymer films. In this case, the absorbance at the max of the chromophore was monitored versus time at a variety of temperatures (18), While the absorbance of PI-2b (Amax 498 nm) was little changed after one hour at 275°C, that of Pl-lb (Amax 474 nm) decreased by almost 30%. In each case, the heating was conducted under an inert atmosphere. Studies such as these are the origin of the data shown in the last column of Table I. 

PH and PD ions for UV-visible spectroscopic studies (cf. pp. 40/2) were obtained by hollow-cathode [7, 8] or microwave [9,10] discharges through helium that contained traces of Hg or D2 and small amounts of phosphorus vapor, by collisions of P+ ions with H2 or D2 molecules [11], and also by electron impact on PH3 [8, 12 to 14]. 

Wren, J. C., Paquette, J., Sunders, S., Ford, B. L. Iodine chemistry in the +1 oxidation state. II. A Raman and uv-visible spectroscopic study of the disproportionation of hypoiodite in basic solutions. Canadian J. of Chemistry 64, 2284-2296 (1986)... 

ELECTROCHEMICAL AND UV-VISIBLE SPECTROSCOPIC STUDIES OF REFRACTORY METALS IN CHLORIDE MELTS... 

Amir-Ebrahimi, V. Byrne, D. Hamilton, J. G Rooney, J. J. A UV/visible spectroscopic study of water-soluble conjugated polyenes prepared via the ring-opening metathesis polymerization reaction. Macromol. Chem. Phys. 1995,196, 327-342. 

UV visible spectroscopic study in hydrocarbon and chlorinated media. Macromol. Chem. Phys., 200, 1215-1221 (c) Babushkin, D.E., Semikolenova, N.V., Zakharov, V.A., and Talsi, E.P. (2000) Mechanism of dimethylzirconocene activation with methylaluminoxane ... 

Liu, S.-Q., Cao, M.-L., and Dong S.-L., 2008. Electrochemical and ultraviolet-visible spectroscopic studies on the interaction of deoxyribonucleic acid with vitamin Bg. Bioelectrochemistry. 74 164-169. 

A UV-visible spectroscopic study of 3 and related substances revealed a strong solvatochromic effect, which served as the basis of the establishment of a solvent polarity scale (Buncel and Rajagopal, 1989, 1990,1991). The theoretical study of Rauhut et al. (1993) was based on AMI methodology (Dewar and Storch, 1985,1989) but used a double electrostatic reaction field in a cavity, dependent on both the relative permittivity and the refractive index. Nuclear motions interact with the medium through the relative permittivity, but electronic motions are too fast only the extreme high-frequency part of the dielectric constant is relevant. These authors were able to evaluate solvent-specific dispersion contributions to the solvation energy. The calculations reproduced satisfactorily the experimental solvatochromic results for 3 in 29 different solvents. The method has also been successfully applied to other solvatochromic dyes, including Reichardt s .j,(30) betaine. 

Schmidt R, Das PK, Welch MB, Knudsen RD (2004) AWW-Tridentate iron(II) and vanadium (III) complexes, part III, UV-visible spectroscopic studies of reactions of ethylene-oligomerization and polymerization catalysts with methyl alnminoxane cocatalysts. J Mol Catal A Chem 222(l-2) 27 5. doi 10.1016/81381-1169(04)00409-1... 

Although considerations such as these have led to a less active field of UV/visible spectroscopic study compared with infrared study, this wavelength region offers some unique advantages, particularly for studies oriented toward kinetics, dynamics, thermodynamics, and mechanisms of gas-phase ion chemistry. As a particular example, we can mention the ability to initiate a chemical process with the insertion of a very accurately known (single-photon) increment of several eV of internal energy at a precisely determined time (for a view of some of these possibilities, see, for instance, [132]). Control of photon polarization is possible [133]. Moreover, excited electronic reaction and dissociation pathways, often involving radical ion chemistry, can be accessed in this way, which is not possible with vibrational activation. 

Conductometric and UV-visible spectroscopic studies of solutions of tellurium in chlorosulfonic acid indicated that the red colour of the solution is due to the formation of the Te4 cation. In the presence of oxidizing agents, e.g. potassium persulfate, the red (Te4 " ) cation is converted into the yellow Te4 cationic species and with excess oxidant tellurium oxide (Te02) is formed. Other workers isolated the compounds Te4(S03Cl)2 and Te2(S03Cl)2, which on dissolution in chlorosulfonic acid afforded the Te4 " and Te2 + cations. Experiments demonstrate that solutions of selenium and tellurium in chlorosulfonic acid in the presence of... 

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