PE spectroscopy

The factor limiting the resolution in ultraviolet photoelectron spectra is the inability to measure the kinetic energy of the photoelectrons with sufficient accuracy. The source of the problem points to a possible solution. If the photoelectrons could be produced with zero kinetic energy this cause of the loss of resolution would be largely removed. This is the basis of zero kinetic energy photoelectron (ZEKE-PE) spectroscopy. 

PE spectroscopy has also been applied to the study of the conformational equilibria of saturated heterocyclic six-membered rings, and in particular of hexahydropyridazines. The... 

Applications of MO methods to such diverse problems as aromaticity, tautomeric structure, dipole moments, and UV, NMR and PE spectroscopy are discussed in various monograph chapters. 

Theoretical methods ranging from the now obsolete HMO studies to ab initio calculations have been used extensively on pyrazoles. Although not emphasized in earlier reviews (66AHC(6)347,67HC(22)l), the most recent publications (B-76MI40402,79RCR289) contain several references to theoretical studies. Some publications related to structural studies are to be found in the following sections, especially in connection with NMR spectroscopy (Section 4.04.1.3.4), UV spectroscopy (Section 4.04.1.3.6), PE spectroscopy (Section 4.04.1.3.9) and tautomerism (Section 4.04.1.5). 

Carbazole, 2-hydroxy-reactions with citral, 4, 235 Carbazole, 2-hydroxy-9-methyl-synthesis, 4, 294 Carbazole, N-hydroxymethyl-as metabolite of carbazole, 1, 230 Carbazole, N-isopropyl-PE spectroscopy, 4, 190 Carbazole, A7-methyl- N NMR, 4, 175 X-ray spectroscopy, 4, 163 Carbazole, 1-nitro-synthesis, 4, 282 Carbazole, tetrahydro-dehydrogenation, 4, 282, 312 synthesis, 4, 107, 337, 353 Carbazole, 1,2,3,4-tetrahydro-reduction, 4, 255, 256 synthesis, 4, 312, 325, 352 Carbazole, 1,2,3,4-tetrahydro-1 -oxo-synthesis, 4, 337 Carbazole, 9-trifluoroacetyl-synthesis, 4, 218 Carbazole, vinyl-polymers, 1, 275, 301 Carbazole, 9-vinyl-copolymer... 

Oxazolidin-5-one, bis(trifluoromethyl)-reactions, 6, 213 Oxazolidinones polymers, 1, 281-282 reactions, 6, 213 Oxazolidinones, imino-rearrangement, 5, 775 Oxazolidinones, vinyl-polymers, 1, 281 Oxazolidin-2-ones circular dichroism, 6, 185 H NMR, 6, 181 IR spectroscopy, 6, 183 PE spectroscopy, 6, 183 reactions, 6, 213... 

Paal-Knorr synthesis, 4, 118, 329 Pariser-Parr-Pople approach, 4, 157 PE spectroscopy, 4, 24, 188-189 photoaddition reactions with aliphatic aldehydes and ketones, 4, 232 photochemical reactions, 4, 67, 201-205 with aliphatic carbonyl compounds, 4, 268 with dimethyl acetylenedicarboxylate, 4, 268 Piloty synthesis, 4, 345 Piloty-Robinson synthesis, 4, 110-111 polymers, 273-274, 295, 301, 302 applications, 4, 376 polymethylation, 4, 224 N-protected, 4, 238 palladation, 4, 83 protonation, 4, 46, 47, 206 pyridazine synthesis from, 3, 52 pyridine complexes NMR, 4, 165... 

Tellurophene, 1,1-diiodotetrahydro-synthesis, 4, 963 Tellurophene, 2,5-diphenyl-alkylation, 4, 948 lithiation, 4, 949 Tellurophene, 2-halo-PE spectroscopy, 4, 25 Tellurophene, 2-lithio-reactions, 4, 79... 

Tellurophene, 2-methylmercapto-conformation, 4, 944 Tellurophene, 2-phenyl-irradiation, 4, 946 mass spectra, 4, 942 photolysis, 4, 42 Tellurophene, tetrachloro-synthesis, 4, 118, 963 Tellurophene, tetradeutero-synthesis, 4, 964 Tellurophene, tetrahydro-conformation, 4, 938, 944 IR spectra, 4, 942 mass spectra, 4, 24, 943 PE spectroscopy, 4, 26 reactions, 4, 88, 958 ring strain, 4, 28 synthesis, 4, 118, 962, 963 Tellurophene, tetraphenyl-cycloaddition reactions, 4, 951... 

The structures of the new bicyclic peroxides have been established by the usual combination of physical techniques and chemical transformations. Here we highlight features of the H and 13C n.m.r. spectroscopic data that provide the best characterization of these compounds their reactions are discussed later. Information about the C-O-O-C dihedral angle in organic peroxides is potentially available from photoelectron (PE) spectroscopy. Measurements on comparatively rigid systems play an important part in establishing a soundly based experimental correlation, and the results obtained on several of these bicyclic peroxides are presented in this section also. 

Important thermodynamic properties that relate to the structure and stability of the chalcogen ailotropes and their polyatomic cations are the formation enthalpies listed in Table 2. Only reliable experimentally or quantum chemically established numbers have been included. From Table 2 it is evident that tellurium is the least investigated with respect to the entries thus, there is clearly space for more thorough experimental or quantum chemical work in this direction. Therefore, we have assessed the missing Te data from the IP determination in ref. 12 (PE spectroscopy) and ref. 13 (quantum chemical calculations) and have put them in the table in parentheses, although it is clear that the associated error bars are relatively high. The data in ref. 14 were not considered. 

Note Values in bold are from the NIST,15 values in parentheses have been put together by the author from PE-spectroscopy data12 of Te and Te calculations (n = 1-6).13... 

The theoretical and experimental principles of PE spectroscopy have been reviewed extensively7-10. In particular, the reader is referred to the chapter The Photoelectron Spectra of Saturated Hydrocarbons in the volume The Chemistry of Alkanes and Cycloalkanes of the present series11. Consequently we shall limit ourselves to the essentials needed for following the arguments presented in this chapter. 

The disproof of the naive expectation that the PE spectrum of a (non-planar) hydrocarbon containing z non-conjugated double bonds would show z 7r-bands, where each one corresponds to the removal of an electron from only one of the z localized two-centre Tr-orbitals, was one of the earliest successes of PE spectroscopy. In particular, if in a... 

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