Pyrazolines spectrum

An important point is that the electrochemically driven charge transport in these polymeric materials is not dependent on the presence of mixed valence interactions which are well known to give rise to electronic conductivity — in a number of cation radical crystalline salts. This is clearly seen from the absorption spectrum of the electrochemically oxidized pyrazoline films (Figure 8) which show no evidence for the mixed valence states that are the structural electronic prerequisites for electrical conductivity in the crystalline salts. A more definitive confirmation of this point is provided by the absorption spectrum (Figure 10) of electrochemically oxidized TTF polymer films which shows... 

The diradical species trimethylenemethane (42) was first discovered by Dowd in 1966 from cleavage of the pyrazoline, and was characterized by its ESR spectrum and the formation of methylenecyclopropane (equation 67). The study of diradicals has a long history (equation 3), " and many examples have been studied. ... 

Fluorescence studies of the commercially important l,3-diphenyl-2-pyrazoline derivatives have been extended to a wide range of phenyl- and methyl-substituted derivatives. The fluorescence yields in non-polar solvents are all close to unity, with the exception of l,3,5,5-tetraphenyl-2-pyrazoline. This is not the case in methanol, when a large variation in yields is observed.85 (See the section on oxidation for other photochemical processes in these compounds.) By an examination of the fluorescence spectra and fluorescence excitation spectra of 9-amino-acridine at 4.2 K, the fine-structure fluorescence spectrum of the neutral molecule has been identified and investigated using laser excitation.88... 

The azo dyes were identified by elemental analysis and MS,IR and NMR spectra, and it was proved by the studies of tautomerism of the azo dyes with IR and NMR spectra that hydrazone form was predominant in the azo dyes. First,the absorption peak of 1660, 1600, 1560 and 1260 cm" in IR spectrum of 4- were all compatible with the absorption peak CO, Endo C N, Exo C—N and NH of hydra-zone, respectively, that were exactly identified on arylazo-3-methyl-1-phenyl-2-pyrazolin-5-one... 

Bis(ketenyl)pyrazoline (79a) was formed by photolysis of the bis(diazoacetyl) precursor 78, and identified by the ketenyl IR absorption in CH3CN, at 2123 and 2133 cm and when generated in methanol gave the diester (Eqn (4.41)).The bis(ylide) 79b formed with the bisketene (Eqn (4.42)), as identified by the characteristic UV spectrum, and computations suggest this exists as two bond-stretch... 

The IR spectrum of CuL-4H20, where H2L = 2-amino-4-methylthiazole-dipropionic acid, is consistent with 1 coordination through amine N and two carboxylate O atoms.IR ligand bands for Cu(o-haph)2L2, where o-haph = o-hydroxyacetophenone, L = range of 2- or 3-pyrazoline-5-one derivatives, show that L is coordinated via O or N+O atoms. 

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