Fluorescence excitation and depletion spectroscopy of the BAr complex: Electronic states correlating with the excited valence B(2s2p2 2D) asymptote

Abstract

A study on the anisole-water complex by molecular beam-electronic spectroscopy and molecular mechanics calculations Laser fluorescence excitation spectroscopy of the CAr van der Waals complex Experimental and theoretical study of the electronic spectrum of the BAr 2 complex: Transition to the excited valence B(2s2p 2 2 D) state

Experimental and theoretical study of the electronic spectrum of the BAr2 complex: Transition to the excited valence B(2s2p2 2D) state

“…35 The C 2 ⌬ state was detected only through fluorescence depletion spectroscopy. 31 In similar fashion, we have been unable to detect near-resonance fluorescence from the BAr 2 complex for laser wavelengths near that of the 2s2p 2 2 D←2s 2 2 p 2 P valence transition.…”

“…In our spectroscopic study of diatomic BAr electronic states correlating with the B(2s2 p 2 2 D)ϩAr asymptote, 31 the weakly bound D 2 ⌸ and E 2 ⌺ ϩ states were observed to decay radiatively, while the strongly bound C 2 ⌬ state was found to decay nonradiatively, 31 by predissociation through a repulsive 4 ⌸ state. 35 The C 2 ⌬ state was detected only through fluorescence depletion spectroscopy.…”

“…While the electronic spectrum of the binary BAr complex shows well-resolved vibrational bands, its spectrum also covers a similar spectral region around the B atomic line. 31 Strictly speaking, the molecular carrier of the emission spectrum shown in Fig. 1͑a͒ can be the ternary BAr 2 or a higher BAr n complex, or a combination of several such complexes.…”

“…Fluorescence depletion experiments were carried out by overlapping this tunable laser beam with a second tunable laser beam ͑Continuum ND6000͒, as described previously. 30,31 The laser-induced fluorescence signal passed through a 1/4 m monochromator and was detected with a photomultiplier ͑Thorn EMI 9813QB͒, whose output was directed to a gated integrator and thence to a laboratory computer. A portion of the fundamental output of the first dye laser was directed through a solid-fused silica etalon ͑free spectral range 1.18 cm Ϫ1 ) in order to provide wave number markers.…”

“…27 We have characterized the potential energy curve of the single, B 2 ⌺ ϩ state arising from the B(2s 2 3s 2 S) ϩNe,Ar asymptote 28,29 and those of the C 2 ⌬,D 2 ⌸, and E 2 ⌺ ϩ states correlating with B(2s2p 2 2 D)ϩNe,Ar. 30,31 Electronic absorption spectra have been reported for boron atoms trapped in argon and hydrogen matrices. 12 higher energy than that of the first transition in free atomic boron ͑249.8 nm͒.…”