Vibrational transitions series

The original theory of individual state-selective vibrational transitions induced by IR femtosecond/picosecond laser pulses has been developed by Paramonov and Savva et al. for single laser pulses [13] (see also Ref. 23) followed by more general extensions to series of IR femtosecond/picosecond laser pulses in Refs. 14 and 24. For illustration, let us consider two simple, one-dimensional model systems that are assumed to be decoupled from any... 

Figure 3. Selective vibrational transitions OH(l>, = 0) - OH(ty = 5) and OH(u, = 5)->-OH(iy = 10) induced by two individual IR femtosecond/picosecond laser pulses. The electric fields c(i) and the population dynamics Pv(t) are shown in panels (a) and (b), respectively. Sequential combination of the two individual laser pulses yields the overall transition OH(u = 0) - OH(u = 5) - OH(u/ = 10) cf. Fig. 1 and Table I. For the isolated system, the population of the target state Pv= fo(t) is constant after the series of IR femtosecond/picosecond laser pulses, i > 1 ps.

Combination of several individual vibrational transition (Section III.A) yields a selective sequence of vibrational transitions induced by series of IR femtosecond/picosecond laser pulses. For example, the two individual transitions (12), (13) may be combined to the sequence... 

Figure 6. Series of IR femtosecond/picosecond laser pulses for the sequence of vibrational transitions SBV(u = 0) - SBV(u = 6) - SBV(t> = 1) for laser control of the Cope rearrangement of the model substituted semibullvalene (SBV) shown in Fig. 2 (adapted from Ref. 26). The notations are as in Fig. 3. The electric field is scaled by the scaling factor / of the effective charge associated with the dipole function jt =/ e q.

An absorption spectrum is the result of electronic, vibrational, and rotational transitions. The spectrum maximum (the peak) corresponds to the electronic transition line, and the rest of the spectrum is formed by a series of lines that correspond to rotational and vibrational transitions. Therefore, absorption spectra are sensitive to temperature. Raising the temperature increases the rotational and vibrational states of the molecules and induces the broadening of the recorded spectrum. 

In another series of papers [26] Shin has used the WKB (Wentzel-Kramers-Brillouin) method for evaluating the vibrational transition matrix element, employing various forms of interaction potential. Comparisons are made with quantum-mechanical solutions. 

In the case of iron phthalocyanine catalyst dispersed on carbon, infrared spectroscopy measurements enabled to confirm the series mechanistic pathway for the ORR in the high overpotential domain (below 0.7 V vs RHE). Two intermediates species, 02 and H02 and two products, water (majority product) and hydrogen peroxide could be identified. However, since only few studies are led on the oxygen reduction reaction by infrared spectroscopy, a confident attribntion of the different vibrational transitions observed to a particnlar intermediate remains difficult. 

P, Hennig, W. P, Kraemer and 6. H. F. Oierckseni A Compilation of Theoretical Spectroscopic Constants and Rotational-Vibrational Transition Frequencies for the Isoelectronic Series of Linear Triatomic Molecules HCN, HNC, HCO , HOC", HNN Obtained from Ab Initio Calculated Energy Hypersurface, Max-Plenck-Insti-tut fur Physik und Astrophysik, Munich 1977. 

Abstract. — The preparation and some properties of AuF salts of each of the following cations is described Xe2FJ "j, XeF, K", Cs", NO", and IF. These salts show structural relationships to their noble-metal relatives. The diamagnetism of the AuF anion, its octahedral symmetry and its vibrational behavior, are in accord with the low-spin electron configuration dt of the Au(V). The AuF ion is the smallest and most powerfully oxidizing MF species of the third transition series. From the magnetic susceptibility of O AuF, which obeys a Curie-Weiss relationship with d = 3 , the magnetic moment of has been found to be 1.66 BM. 

An indirect yet powerful tool to monitor the metal adsorption sites is to study CO adsorption. CO is widely used as a probe molecule because of its low reactivity and quite sensitive vibrational frequency Small changes in the substrate electronic structure reflect into measurable changes in CO stretching frequency. The study of CO desorption temperature from a metal covered MgO film and of the IR bands associated to the formation of metal-carbonyl complexes provides an useful tool to identify the surface sites involved in the stabilization of the M-CO species [31]. However, for an atomistic view of the sites involved, it is essential to combine the experimental evidences with the results of ab initio calculations. Recently, this has been done for a series of transition metal atoms, Rh, Pd, and Ag, all belonging to the second transition series but characterized by quite different valence structures (Rh, d Pd, di° Ag, d si) [211,212]. 

As will be shown in Sec. 1.23, a long series of overtone bands can be observed when Raman spectra of small molecules such as I2 and Til4 are measured under rigorous resonance conditions. Anharmonicity constants can also be determined from the analysis of rotational fine structures of vibrational transitions [2]. 

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