Methyl complexes, charge transfer spectra

Laali and Lattimer (1989 see also Laali, 1990) observed arenediazonium ion/crown ether complexes in the gas phase by field desorption (FD) and by fast atom bombardment (FAB) mass spectrometry. The FAB-MS spectrum of benzenediazonium ion/18-crown-6 shows a 1 1 complex. In the FD spectrum, apart from the 1 1 complex, a one-cation/two-crown complex is also detected. Dicyclo-hexano-24-crown-6 appears to complex readily in the gas phase, whereas in solution this crown ether is rather poor for complexation (see earlier in this section) the presence of one or three methyl groups in the 2- or 2,4,6-positions respectively has little effect on the gas-phase complexation. With 4-nitrobenzenediazonium ion, 18-crown-6 even forms a 1 3 complex. The authors assume charge-transfer complexes such as 11.13 for all these species. There is also evidence for hydride ion transfer from the crown host within the 1 1 complex, and for either the arenediazonium ion or the aryl cation formed from it under the reaction conditions in the gas phase in tandem mass spectrometry (Laali, 1990). 

In order to include a wider range of solvents than those in which any of the Y values can be conveniently measured, other attempts have been made at correlating solvent polarities.395 Kosower found that the position of the charge-transfer peak (see p. 79) in the uv spectrum of the complex (87) between iodide ion and 1-methyl- or l-ethyl-4-carbometh-... 

Benzo[a]quinolizinium (ions), methyl-, reactivity, 55, 349 BenzoIWquinolizinium (ions/salts) calculated electron densities, 55, 275 calculated electronic spectrum, 55, 324 charge transfer complexation, 55, 352 halogenation, 59, 331 photodimerisation in solid state, 55, 320, 352... 

In the presence of maleic anhydride, the ultraviolet-induced terpolymer-ization of A/-vinylpyrrolidone, methyl methacrylate, and maleic anhydride exhibits charge-transfer polymerization characteristics without any zinc chloride being present [90]. The mixture of N-vinylpyrrolidone and maleic anhydride, on exposure to ultraviolet radiation, changes color from yellowish through pink to scarlet. The ultraviolet spectrum indicates the formation of a one-to-one complex. 

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