Chloride, formation constants with

Solid-surface room-temperature phosphorescence (RTF) is a relatively new technique which has been used for organic trace analysis in several fields. However, the fundamental interactions needed for RTF are only partly understood. To clarify some of the interactions required for strong RTF, organic compounds adsorbed on several surfaces are being studied. Fluorescence quantum yield values, phosphorescence quantum yield values, and phosphorescence lifetime values were obtained for model compounds adsorbed on sodiiun acetate-sodium chloride mixtures and on a-cyclodextrin-sodium chloride mixtures. With the data obtained, the triplet formation efficiency and some of the rate constants related to the luminescence processes were calculated. This information clarified several of the interactions responsible for RTF from organic compounds adsorbed on sodium acetate-sodium chloride and a-cyclodextrin-sodium chloride mixtures. Work with silica gel chromatoplates has involved studying the effects of moisture, gases, and various solvents on the fluorescence and phosphorescence intensities. The net result of the study has been to improve the experimental conditions for enhanced sensitivity and selectivity in solid-surface luminescence analysis. 

The silanol groups which had not been esterified on reaction with methanol did still react with thionyl chloride. Gok9ek (231) found that the sum of methoxy content (after reaction with methanol vapor at various temperatures) and chloride formation remained nearly constant. 

The complex formation of partially alkylated PVP was reported by Kabanov et a 42 and by us5S. The K value fell by about two orders of magnitude with the degree of alkylation for the PVP derivatives that were alkylated or quaternized by methyl bromide42. This reduction of K was due to electrostatic repulsion on the quaternized PVP chain. On the other hand, Table 5 shows no effect of alkylation on the stability of the polymer chelate when benzyl chloride is used as the alkylating reagent, while the formation constant falls slightly for PVP alkylated by ethyl... 

These very small values for the thermodynamic functions tend to suggest that chloride ions form very weak complexes indeed if not just forming an ion-pair. The first formation constant, ki, shows a decrease with increase in ionic radii of the halide ions (Table 17). 

When pyridinium hydrochloride was treated at 250°C with iodine monochloride in the presence of aluminium chloride, a 2-pyridylpyridinium salt was formed. Both 1 1 and 1 2 complexes formed when iodine monochloride or iodine reacted with pyridine (80AJC1743). Formation constants for the charge-transfer complexes between iodine and pyridine (and pico-lines) have been measured [84JCS(P2)731], and solvent effects on the... 

A-methylimidazole with the corresponding protoporphyrin IX and protoporphyrin IX dimethyl ester complexes of chloroiron(III) and for the reaction of imidazole (Him) with TPPFeF and (PPDME)FeF. In the latter case, the first intermediate to form is, as before (equation 40), the six-coordinate high-spin PFe(HIm)F, and the second is PFe(HIm)F Him in which an external imidazole is hydrogen bonded to the fluoride. It has also been shown that reaction of hindered imidazoles such as 2-MeImH and 1,2-Me2lm with TPPFeCl introduces a steric strain with the porphyrin ring that causes about a factor of ten decrease in the formation constant, K (equation 40), and a factor of ten or more increase in the rate of chloride ion dissociation (equation 41). ... 

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