Electronic spectra of radicals in a supersonic slit-jet discharge by degenerate and two-color four-wave mixing

Abstract

Four-wave mixing techniques have been used for the measurement of electronic transitions of cold transient species generated in a supersonic slit-jet discharge expansion. The origin band of the d(3)Pi(g)-a(3)Pi(u) system of C(2) and A(2)Pi(3/2)-X[combining tilde](2)Pi(3/2) electronic transition of HC(4)S were recorded. A signal-to-noise ratio of 10(4) in the spectra was achieved, resulting in detection limits of 10(10) cm(-3) for these two molecules. Application of selective two-color resonant four-wave mixing is used for the spectral assignment utilizing the double-resonance nature of the method. The combination of these techniques with a slit source proves to be a sensitive approach for the detection of transient molecules in a molecular beam discharge.

Characterization of C4H in the A2Π and X2Σ+ states by double resonance four-wave mixing

“…The signal beam travels through collimating lenses set on a long pathlength before reaching a photomultiplier. 15 The data were averaged over 40 laser shots and 0.06 cm −1 steps were used for the scans. The degenerate scan allowed selection and detection of specific transitions of C 4 H for the pump laser.…”

“…8 The intense peak corresponds to the A u system of C 2 by two-color four-wave-mixing whenever the intensity of the pump laser was increased. 15 In the present case, the probe frequency is set on the less intense B 3 and 3π 3 open shell configurations. This alternating behavior is similar to that described in the theoretical calculations of the s-o splitting of the HC n S series.…”

Conformational structures of 3-cyanoindole-(H2O) (n= 0–2): Franck–Condon simulations

“…A detailed list of geometrical information is given in Table S1. FC simulations of the vibronic spectra of 3CI have been carried out using pgopher program [19][20][21]. Table 1 Observed peak frequencies (cm −1 ) in the UVHB spectrum, calculated S1 harmonic frequencies (cm −1 ), and the corresponding vibronic assignments for the 3CI-(H2O)n (n = 0-2) clusters.…”

Deperturbation study of the state of C2 by applying degenerate and two-color resonant four-wave mixing

“…In fact, we have shown recently on several transient species (C 3 [28], C 2 [29], HC 4 S [29], HC 2 S [30] and C 2 À [31]) that the excellent sensitivity of TC-RFWM is applicable to the low-density environment of a discharged free-jet. From the combination of the two experimental techniques new possibilities ensue for an advanced treatment of the perturbation problem.…”