The CaCCHÃ2Π–2Σ+522and 520Bands Studied by High Resolution Spectroscopy: The Ca–C–C Bending Vibration and Vibronic Interaction

A high-resolution laser ablation study of the transition of SrCCH

“…In addition, experimental data exist for the excited states of these molecules. For CaCCH, theà 2 P-X 2 R þ transition has been observed experimentally both at low [15,16] and high resolution [17][18][19][20][21], including a determination of the dipole moments for the à andX states of CaCCH using Stark spectroscopy [22]. In addition, theC 2 D-X 2 R þ transition [23] of CaCCH has been observed at low resolution.…”

The C–C–H Bending Vibration Mode (ν4) in the Electronic Ã2Π and X2Σ+ States of the CaCCH Radical

“…In our previous study of the CaOH and CaOD radicals (4), the corresponding parameters have somewhat larger magnitudes, ⑀ ϭ Ϫ0.10 and Ϫ0.098, respectively, than those for CaCCH. However, they are still small when compared with those for the 15-electron species such as NCO (5,6), NCS (7), BO 2 (8,9), and CO 2 ϩ (10, 11), for which the magnitudes of ⑀ are generally in the range between Ϫ0.15 and Ϫ0.20; the exception is the BO 2 Ã 2 ⌸ u state (9), for which ⑀ ϭ Ϫ0.029. The small magnitudes of the Renner-Teller parameters for the Ca-X (X ϭ OH/OD, CCH) radicals may be understood from their electronic structures.…”

“…With the above representations for the upper and lower states, a weighted, nonlinear least-squares fit was performed, including all the measured lines. The weight for the majority of the lines which were well resolved was 1/(0.0035) 2 , corresponding to the measurement accuracy; for blended lines, a smaller weight, 1/(0.01) 2 , was used. The variance of the final fit was 1.369; although this is somewhat larger than unity, it seems quite satisfactory considering the complex nature of the spectrum.…”

Laser spectroscopy of the and transitions of CaCCD

“…In 1995, the ground states of CaCCH and SrCCH were studied using millimeter and submillimeter direct absorption spectroscopy [4,5]. Between 1996 and 1999, Li and Coxon studied many different vibrational bands of the e A 2 P-e X 2 R þ transition in CaCCH [6][7][8][9][10].…”