Iodine solution spectra

Topical 2% povidone iodine solution and 0.2% chlorhexidine gluconate solution have broad antimicrobial profiles and may be used as cheap spectrum and effective antifungal agents in equine ketomycosis, particularly where Fusarium spp. are involved. A1% dermatological cream formulation of silver sulfadiazine has both antifungal and antibacterial properties and is reasonably well tolerated topically in the horse eye. Its use is advocated where cost restraints exist or for prophylaxis in comeal injuries involving embedded plant material (Hamor Whelan 1999). 

Figure 3.3 A typical spectrum obtained from a measurement of an iodine solution with Am as irradiation source. The characteristic iodine peaks are considerably smaller than the peak of Compton-scattered source photons. In the Compton scattering process, which involves the outer electrons, the incoming photon transfers a part of its energy to an atomic electron, which is then knocked out from the atom. The direction of the continuing photon is changed in the process, and the amount of energy loss is determined by the scattering angle.

XRF spectrum obtained on an iodine solution with an americium 241 source (1). 

Figure lb reports the UV-Visible spectrum of the liquid 1,4-bis(triethoxysilyl)benzene, the precursor of the phenylene-bridged PMO, into which traces of iodine have been dissolved. Only one band due to iodine is visible at 362 nm. We suggest this band to be due to I3" ion, which in aqueous solution absorbs at 355 nm [8], The presence of a band at the same wavelength in the case of I2 adsorbed onto AW-Ph-HMM reveals, also in... 

Measure the molecular absorption spectrum in the visible region (400 to 700 nm) of each of the standards. Also measure the molecular absorption spectrum of the heptane layer in the separatory funnel (the extract). You can fill the cuvette conveniently by using a dropper to draw the solution (top layer) out of the separatory funnel. Obtain the maximum absorbance for each and create the standard curve. Determine the concentration of iodine in the extract. 

A classic example of CT complex formation occurs in the solution of iodine (an acceptor) in cyclohexene (a donor), when the solution assumes a brown color due to a shift in its absorption spectrum. The brown is not a color in the physical sense, but rather the result of a very broad absorption band encompassing about 200 nm in the visible spectrum and evolving as a result of electronic changes in the CT complex. In contrast, a solution of iodine in CCI4—an inert solvent—is purple. 

The iodine was removed from the reaction mixtures by vacuum sublimation and subsequently identified by its characteristic spectrum in pyridine solution. A solution of the sublimate from these reaction products gave an absorption maximum at 369 m/jL, while a solution prepared by dissolving elemental iodine in pyridine produced an absorption band of similar shape with a maximum at 370 m. ... 

The compound [PPN]2[Os6(CO)18] is insoluble in hydrocarbons, sparingly soluble in methanol, and very soluble in acetone, acetonitrile, dichlorometh-ane, and chloroform to give solutions that are stable indefinitely at room temperature. Its IR spectrum in CH2C12 exhibits an intense v(CO) absorption at 1991 and very weak absorptions at 1964, 1938, and 1910cm-1. The compound is easily oxidized back to Os6(CO)18 by treatment of a CH2C12 solution with iodine /2.n... 

The absorption spectrum of violet soln. is but little influenced by the nature of the solvent, by the temp, or by the concentration of the soln. With brown soln. of the same concentration, the absorption in the violet end of the visible spectrum and in the ultraviolet is much more marked. H. Gautier and G. Charpy, E. Wiedemann, and H. Ebert explain the peculiarities in the optical properties of iodine soln. by assuming a polymerization of the solute iodine which in the violet soln. contain I2-molecules, and in the brown soln. In+2-molecules. Under any particular set of conditions, there is a state of equilibrium In+2 wl2, which determines the tint of the soln. From measurements of the raising of the vap. press, of iodine in solvents which produce brown and violet soln., M. Loeb assumed that the iodine in the brown soln. is present as I4 molecules and in the violet soln. as I2 molecules. He explained the change from brown to violet with a rise of temp, by assuming that the equilibrium I4 2I2 is displaced in favour of the I2 molecules, and conversely with a lowering of the temp. 

The fusion curve of mixtures of arsenic and iodine shows no evidence of the formation of a pentiodide, but there is a eutectic, of freezing point 71-5° C., which has the approximate composition of this substance.5 The absorption spectrum of the solution in carbon disulphide is similar to that of a mixture of the triiodide and iodine.3... 

Figure 31 shows the change of the absorption spectrum with desorption of iodine a thin PVA film was first soaked in a 1 x 10mol/1 solution, corres-... 

Figure 9.1 Spectrum recorded during the decomposition of a solution of propionyl benzoyl peroxide and iodine in o-dichlorobenzene at 100°C. The numbers in parentheses below the formulas indicate the relative spectrum amplitudes for the underlined protons. Spectrum groups referred to in the text are indicated at the top of the figure. Reprinted with permission from H. R. Ward, Accts. Chem. Res., 5, 18 (1972). Copyright by the American Chemical Society.

In view of the chromophoric character of the elemental iodine itself, many colorimetric methods have been proposed for the determination of inorganic iodine (88—92). These methods use the visible portion of the spectrum in reading iodine concentrations. In the visible range the extinction coefficient for iodine is not high enough to be used for minute quantities of iodine in water and other solvents (93). Higher sensitivities have been reported for elemental iodine in potassium iodide solutions in the ultraviolet (93,94). 

Drug Iodine Principal Indication(s) Adhesive capsulitis and other soft-tissue adhesions microbial infections Treatment Rationale Iodine is a broad-spectrum antibiotic, hence its use in infections, etc. the scle-rolytic actions of iodine are not fully understood Iontophoresis 5°/o-10°/o solution or ointment from negative pole Phonophoresis 10% ointment... 

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