The CaOH radical has been produced in a supersonic molecular beam by the reaction of water vapor with laser desorbed calcium. Three new electronic states, the D 2Σ+, E 2Σ+, and F states have been observed by laser induced fluorescence and resonance enhanced multiphoton ionization spectroscopy. The D and E states are linear, but the F state is bent, the first bent and strongly covalent state of CaOH to be observed. Vibrational constants for the D state have been determined and a partially rotationally resolved spectrum has provided the rotational constant and Ca–OH bond length in this state. The D and E states are more strongly bound than the ground state, perhaps indicating some covalent contribution to the bonding. Additional vibrational constants of the ground electronic state including the CaO–H vibrational frequency have been determined from the emission spectra.

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Eu3+ ions influence on the crystallization process of Y3TaO7 solid solution and this particular host has presented a high concentration quenching (30 mol%), displaying an intense orange-reddish emission, with color purity over 92.6%.

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A laser time-of-flight mass spectrometer setup used to investigate the spectroscopy and dynamics of weakly bound complexes is described. Complexes were produced by laser vaporization of metals into a supersonic expansion of helium and a solvent. The first results consisting of laser ionization and photodepletion spectra of Ba‚‚‚(FCH 3 ) n for 1 e n e 3 are reported. The measurement of the Ba‚‚‚FCH 3 + signal as a function of the ionization photon energy allowed estimation of the complex ionization potential, which was found to be 4.5( 0.1 eV. The photodepletion spectrum of the Ba‚‚‚FCH 3 complex displayed two distinct regions. At longer wavelengths it showed a high cross-section (60-70 Å 2 ) and a well-defined vibrational structure, while a much smaller cross-section (2-4 Å 2 ), with a more diffuse structure, appeared at shorter wavelengths. In addition, clear resonances were observed at longer wavelengths, indicating a significant coupling between the bound excited potential of the complex and the (open channel) ionic potential leading to BaF * + CH 3 reaction products. All of these features are discussed, taking into account the interplay between the spectroscopy and dynamics associated with each electronically excited state of the complex that governs the photoinitiated harpooning reaction.

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Articles you may be interested inPhotodissociation of (SO2XH) Van der Waals complexes and clusters (XH = C2H2, C2H4, C2H6) excited at 32 040-32090 cm−1 with formation of HSO2 and X

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