Spectra of molecular

Bouche Th., Drier Th., Lange B., Wolfrum J., Franck E. U., Schilling W. Collisional narrowing and spectral shift in coherent anti-Stokes Raman spectra of molecular nitrogen up to 2500 bar and 700 K, Appl. Phys. B50, 527-33 (1990). 

The energy difference I/ , -F2I=2 V12 is known as Davydov or exciton splitting, Figure 8.3. The shift of energy levels gives rise to new bands in the absorption spectrum denoted as the upper and lower Davydov (exciton) components. These components are the H- and J-bands observed in absorption spectra of molecular aggregates. 

The intermolecular interaction described above provides information about the magnitude of spectral shifts, but it does not explain why the absorption spectra of molecular aggregates usually have either an H- or J-band. The square of transition dipole moment (in Debye2 units) is usually termed the dipole strength and is related to the intensity of the absorption band as (van Amerongen et al. 2000)... 

Pardi, L.A., Krzystek, J., Telser, J., and Brunei, L.-C. 2000. Multifrequency EPR spectra of molecular oxygen in solid air. Journal of Magnetic Resonance 146 375-378. 

Troisi A, Ratner MA (2005) Modeling the inelastic electron tunneling spectra of molecular wire junctions. Phys Rev B 72(3) 033408... 

Yu L, Zangmeister CD, Kushmerick JG (2007) Origin of discrepancies in inelastic electron tunneling spectra of molecular junctions. Phys Rev Lett 98 206803-206804... 

Tian W, Datta S, Hong S, Reifenberger R, Henderson JI, Kubiac CP (1998) Conductance spectra of molecular wires. J Chem Phys 109 2874... 

As a final example the spectra of molecular charge-transfer complexes are considered next. Electron acceptors such as pyromellitic dianhydride, chloranil and tetracyanobenzene... 

Contents Lattice Dynamics. - Symmetry. - Inter-molecular Potentials. - Anharmonic Interactions. - Two-Phonon Spectra of Molecular Crystals. -Infrared and Raman Intensities in Molecular Crystals. 

To these authors knowledge, it is not practically possible to measure the whole spectra of molecular composition of the conversion gas and the off-gas. Therefore, it is only practical to discuss the empirical formula [CxHyOz] of the conversion gas or the offgas. 

The exact analysis of the HFEPR spectra of molecular magnet clusters is not possible and is usually carried out by beginning with a basic Hamiltonian of the form,... 

The complex between 1,10-phenanthroline and picric acid was stated to be a n-7i complex, not the expected n-n type.362 1,10-Phenanthroline also forms molecular complexes with phloroglucinol,363 halogenated p-nitrophenols 364 hexachlorocyclohexanes,365 and iodine.366,367 It forms an adduct with acetic anhydride.368 Electronic spectra of molecular complexes of 1,10-phenanthroline with porphyrins have been recorded.369... 

The subject matter of the book are the rovibro-translational spectra of molecular complexes. Supermolecular spectra involving electronic transitions will be briefly considered in Chapter 7. We are concerned mostly... 

Besides the isotropic overlap-induced dipole component familiar from the rare gas pairs, we will now in general have other significant induced dipole components if molecules are present, namely multipole-induced and distorted frame-induced dipole components, see Chapter 4 for details. Moreover, these anisotropic dipole components couple with the polarizability tensor and thus give rise to simultaneous transitions in two (or perhaps more) molecules. Furthermore, molecules in general interact with more or less anisotropic forces which to some extent does also affect the spectra of molecular systems. 

M. Perrot and J. Lascombe. Collision-induced effects in allowed infrared and Raman spectra of molecular fluids. In [45], p. 613. 

Figure 22-6 Electron ionization (70 eV) mass spectra of molecular ion region of benzene (C4H6) and biphenyl (C,2H,0). [From Nisr/EPA/NIH Mass Spectral Database...

Figure 7. Comparison of the K-shell energy-loss spectra of molecular nitrogen obtained using electron impact and synchrotron radiation.

Figure 6. A series of energy loss spectra of molecular NO and its dissociation products adsorbed on Ru(001) (14) (a) follows an exposure of mo °f 22 torr-s ( Xo = 0.15) at T — 150 K on clean Ru(001) (b) follows heating the surface represented in (a) to 250K (c) follows exposing the surface represented in (b) to 43 torr-s...

Figure 1. (a) - Photo luminescence spectra of atomic cryocrystals at T= 5 K under excitation energy h v=Eg. (b) - (1-3) Excitation spectra of molecular luminescence bands of solid Ar (4) - absorption spectrum of solid Ar (from Ref.7). 

Direct evidence of the existence of organomagnesium compounds with a cluster metal core has been obtained by matrix-assisted laser desorption/ ionizaiton time-of-flight mass spectrometry (MALDI-TOF MS). This method allows one to record the spectra of molecular ions [MH]+ of pro-tonated molecules M. The major advantage of this method is that the use of volatile matrices makes it possible to measure the mass spectra of compounds that hardly transform to the gas phase under other conditions. This is true in full measure for organomagnesium compounds. The method does not provide detailed information on the geometry of corresponding... 

Figure 4 Absorption spectra of molecular chlorine versus temperature between 390 and 530°C...

Figure 15 Thermal desorption spectra of molecular and dissociative states of N2 fromW(l 00) (grey curve) andW(l 0 0)—c(2 x 2)Cu (black curve) [117]. For W(1 00) a flash desorption is performed with a heating rate of 860 Ks-1 and the dosing temperature is Ts = 75 K. For the alloy, results below 350 K were performed with a thermal source with the heating rate at 25 K s-1 and the dosing temperature Ts 75 K, while for results above 800K the heating rate was 110 Ks-1, Ts = 650 K with a 1.48eV beam. In both cases d>i =0°.

The experiments described demonstrate that it is possible to detect the spectra of molecular cations in the presence of a large magnetic field, despite the expected spatial displacement. Several other cations have since been detected by FIR LMR, both atoms and molecules. 

We conclude this section on modulation spectrometers by describing a particularly novel and important method, known as velocity modulation, which was originally developed by Gudeman, Begemann, Pfaff and Saykally [10]. It applies specifically to ionic species, and has been used primarily to study the infrared vibration-rotation spectra of molecular ions. If we need an excuse to include it in this book, however, it is provided by Matsushima, Oka and Takagi [11] who used the method to study the far-infrared rotational spectrum of the HeH+ ion. 

Figure 10.14. Velocity modulation spectrometer introduced by Gudeman, Begemann, Pfaff and Saykally [10] to study the infrared vibration-rotation spectra of molecular ions.

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