Fourier transform spectroscopy of NiCl: identification of the [12.3] 2Σ+–B2Σ+ transition

✍ Scribed by C.A. Rice; L.C. O’Brien

• Book ID: 104151889
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 107 KB
• Volume: 221
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1016/s0022-2852(03)00218-2

✦ Synopsis

Nickel monochloride, NiCl, has been studied by several spectroscopic research groups in recent years [1][2][3][4][5][6]. From these efforts, a consistent picture has been developed with respect to the five low-lying electronic states which correlate to the Ni þ (3d 9 )Cl À (3p 6 ) electronic configuration: the X 2 P 3=2 state at T 0 ¼ 0 cm À1 , the A 2 D 5=2 state at T 0 ¼ 161 cm À1 , the X 2 P 3=2 state at T 0 ¼ 382 cm À1 , the A 2 D 3=2 state at T 0 ¼ 1646 cm À1 , and the B 2 R þ state at 1768 cm À1 . Additionally, our laboratory has identified two excited states, a [12.3] 2 R þ state and a [13.0] 2 P 3=2 state from the analyses of transitions from these states connecting to the X 2 P 3=2 ground state [5,6]. This note identifies a new electronic transition near 10,500 cm À1 , shown to be the

transition of NiCl near 10,500 cm À1 was recorded in emission using the Fourier transform spectrometer associated with the McMath-Pierce Solar Observatory at Kitt Peak, AZ. The excited NiCl molecules were produced in a King-type carbon tube furnace, loaded with approximately 25 g of NiCl 2 in 50 Torr He heated to 1700 °C.

Using the published constants of the [12.3] 2 R þ state [5] and published constants for the B 2 R þ state [3], we were able to identify three branches in the

by predicting the position of the expected transitions. Interestingly, the expected pattern for a 2 R þ -2 R þ parallel transition, two P branches and two R branches, was not observed. In our spectrum, the Q fe , R ff , and P ee branches were observed, the R ee and P ff branches were not observed at all, and the Q ef branch was obscured by other branches and not identified. A portion of the spectrum is presented in Fig. 1.