Electronic spectra of

Electronic spectra of surfaces can give information about what species are present and their valence states. X-ray photoelectron spectroscopy (XPS) and its variant, ESC A, are commonly used. Figure VIII-11 shows the application to an A1 surface and Fig. XVIII-6, to the more complicated case of Mo supported on TiOi [37] Fig. XVIII-7 shows the detection of photochemically produced Br atoms on Pt(lll) [38]. Other spectroscopies that bear on the chemical state of adsorbed species include (see Table VIII-1) photoelectron spectroscopy (PES) [39-41], angle resolved PES or ARPES [42], and Auger electron spectroscopy (AES) [43-47]. Spectroscopic detection of adsorbed hydrogen is difficult, and... 

The above three sources are a classic and comprehensive treatment of rotation, vibration, and electronic spectra of diatomic and polyatomic molecules. 

High-resolution spectroscopy used to observe hyperfme structure in the spectra of atoms or rotational stnicture in electronic spectra of gaseous molecules connnonly must contend with the widths of the spectral lines and how that compares with the separations between lines. Tln-ee contributions to the linewidth will be mentioned here tlie natural line width due to tlie finite lifetime of the excited state, collisional broadening of lines, and the Doppler effect. 

Duschinsky F 1937 On the interpretation of electronic spectra of polyatomic molecules. I. Concerning the Franck-Condon Principle Acta Physicochimica URSS 7 551... 

Rossetti R, Nakahara S and Brus L E 1983 Quantum size effects In the redox potentials, resonance Raman spectra and electronic spectra of CdS crystallites In aqueous solution J. Chem. Phys. 79 1086... 

G. Herzberg, Moleculer Spectra and Molecular Structure III. Electronic Spectra of Polyatomic Molecules, Van Nostrand, New York, 1967. 

Use Coringuration Interaction to predict electronic spectra of molecules. The Con ngiiration Interaction wave function provides a ground state plus soin e excited state energies. You can obtain electron ic absorption frequencies from the differences betw een the energies of the ground state and the excited states. 

The electronic spectra of benzenoid systems differ in a characteristic manner from their acyclic analogues. Thus benzene, unhke hexatriene. 

Za,b = integrals are retained. In the INDO approach, the values of these single-atom integrals are determined by requiring the results of the calculation, performed at the Fock-like orbital level, to agree with results of ab initio Fock-level calculations. In the MINDO approach, experimental electronic spectra of the particular atom are used to... 

Electronic spectroscopy is the study of transitions, in absorption or emission, between electronic states of an atom or molecule. Atoms are unique in this respect as they have only electronic degrees of freedom, apart from translation and nuclear spin, whereas molecules have, in addition, vibrational and rotational degrees of freedom. One result is that electronic spectra of atoms are very much simpler in appearance than those of molecules. 

As is the case for diatomic molecules, rotational fine structure of electronic spectra of polyatomic molecules is very similar, in principle, to that of their infrared vibrational spectra. For linear, symmetric rotor, spherical rotor and asymmetric rotor molecules the selection mles are the same as those discussed in Sections 6.2.4.1 to 6.2.4.4. The major difference, in practice, is that, as for diatomics, there is likely to be a much larger change of geometry, and therefore of rotational constants, from one electronic state to another than from one vibrational state to another. 

D. S. McClure, Electronic Spectra of Molecules and Ions in Crystals, Academic Press, Inc., New York, 1959. 

Electronic spectra of reduced mixed POMs (RMC) are identical with spectra obtained in conditions of analysis. Spectmm of RMC having two bands at 720 nm in visible region and another at 890 nm differs from the spectmm of 12-MPB in which only one prominent band is present at 800-840 nm. Spectra in organic solvents were displaced to 670 nm for RMC and to 720 nm for 12-MPB. 

Interaction of EMT with chlorine and monochloramine has been studied. Electronic spectra of EMT and of its product of oxidation by chlorine and monochloramines have been obtained. X = 470 nm for EMT, 400 nm and... 

The acidity of a lydrocarbon can be determined in an analogous way. If the electronic spectra of the neutral and anionic forms are sufficiently different, the concentrations of each can be determined directly, and the equilibrium constant for... 

Apart from TiO and the lower halides already mentioned, the chemistry of these metals in oxidation states lower than 3 is not well established. Addition compounds of the type [TiCl2L2] can be formed with difficulty with ligands such as dimethylformamide and acetonitrile, but their magnetic properties suggest that they also are polymeric with appreciable metal-metal bonding. However, the electronic spectra of Ti in TiCl2/AlCl3 melts and also of Ti incorporated in NaCl crystals (prepared by... 

Table A Electronic spectra of some complexes of nickel(II)...

Dilute solid solutions of Ln ions in Cap2 may be reduced by Ca vapour to produce Ln ions trapped in the crystal lattice. By their use it has been possible to obtain the electronic spectra of Ln ions. 

The electronic spectra of actinide compounds arise from three types of electronic transition ... 

Theoretical studies of the relative stabilities of tautomers 14a and 14b were carried out mostly at the semiempirical level. AMI and PM3 calculations [98JST(T)249] of the relative stabilities carried out for a series of 4(5)-substituted imidazoles 14 (R = H, R = H, CH3, OH, F, NO2, Ph) are mostly in accord with the conclusion based on the Charton s equation. From the comparison of the electronic spectra of 4(5)-phenylimidazole 14 (R2 = Ph, R = R3 = H) and 2,4(5)-diphenylimidazole 14 (R = R = Ph, R = H) in ethanol with those calculated by using ir-electron PPP method for each of the tautomeric forms, it follows that calculations for type 14a tautomers match the experimentally observed spectra better (86ZC378). The AMI calculations [92JCS(P1)2779] of enthalpies of formation of 4(5)-aminoimidazole 14 (R = NH2, R = R = H) and 4(5)-nitroimidazole 14 (R = NO2, R = R = H) point to tautomers 14a and 14b respectively as being energetically preferred in the gas phase. Both predictions are in disagreement with expectations based on Charton s equation and the data related to basicity measurements (Table III). These inconsistencies may be... 

It is also interesting that the hypothetical helicene 255 has been incorporated in a study of the jt -electron spectra of a series of infinite helicenes composed of various structural units (77BAU2532). A compound 256, closely resembling an indolo-[2,3-c]carbazole but possessing an additional six-membered ring between the... 

The electronic spectra of radicals 101 and 102 have two sets of absorption bands in the visible andnear-UV regions (Fig. 1, Table XXXII). 

Moffitt, W., Proc. Roy. Soc. [London) A218, 486, The electronic spectra of conjugated hydrocarbons." Allyl radical treated as an example. 

Electronic spectra of these complexes, as Fig. 18 shows, contain two new bands, one of which (long wave) is due to the acceptor absorption and the other... 

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