The interacting B 4Σ− and d 2Π states of CrN: A laser induced and dispersed fluorescence study

Abstract

First observation and electronic spectroscopy of chromium mononitride: The A4Πr←X4Σ− transition near 745 nm Chromium mononitride molecules have been produced in a laser vaporization molecular beam source using Cr metal and ammonia. The complex CrN LIF spectra between 430 and 490 nm have been examined in detail and representative bands in three new electronic subsystems, labeled B 4 ⌺ Ϫ ←X 4 ⌺ Ϫ , d 2 ⌸ 3/2 ←X 4 ⌺ Ϫ , and d 2 ⌸ 1/2 ←X 4 ⌺ Ϫ , have been rotationally analyzed. Perturbations between the B 4 ⌺ Ϫ and d 2 ⌸ states and their dependence on vibrational quantum numbers have been examined. Dispersed fluorescence ͑DF͒ spectra have been recorded which provided a measure of the state mixing. The DF spectra also reveal the presence of an electronic state of CrN with Tϳ6000 cm Ϫ1 , identified as the a 2 ⌺ Ϫ state. Molecular parameters in the B 4 ⌺ Ϫ , d 2 ⌸, and a 2 ⌺ Ϫ states have been established.

Jet-Cooled Optical Spectroscopy of FeN between 16 300 and 21 600 cm−1

“…A number of transition metal nitrides have recently been studied. For the 3d transition metal family, ScN (6), TiN (7)(8)(9)(10)(11)(12)(13), VN (14 -17), and CrN (17)(18)(19) have been studied in the gas phase. Theoretical calculations for ScN (20 -21), , VN (26,27), CrN (26,28), , NiN (29), and CuN (31) have also been reported.…”

Density Functional Investigation of High-Spin XY (X = Cr, Mo, W and Y = C, N, O) Molecules

“…Diatomic molecules containing elements in the first transition series have been heavily studied, both experimentally [1][2][3][4][5][6][7][8] and theoretically. [9][10][11][12][13][14][15] The methodological requirements, including both basis set flexibility and extent of electron correlation recovery, for reliable computational results have been the subject of a recent excellent review, 16 which also provided abundant interpretive examples of the TM-main group element bond.…”

“…Diatomic molecules containing elements in the first transition series have been heavily studied, both experimentally − and theoretically. − The methodological requirements, including both basis set flexibility and extent of electron correlation recovery, for reliable computational results have been the subject of a recent excellent review, which also provided abundant interpretive examples of the TM−main group element bond. Reports on compounds involving TMs from the 4d row are much less common. − While several specific molecules have been observed and calculated, we know of no comparable systematic review of theoretical treatments.…”

CrN, CuB, and AuB: A Tale of Two Dissociation Limits

“…Like YbO, the high density of states found in the spectrum of CrN displayed in Figure is likely due to ion pair states, in this case diabatically correlating to Cr + 3d 5 , 6 S g + N – , 2p 4 , and 3 P g , which drop down into the energetic region spanned in Figure . Indeed, previous spectroscopic work has identified the A 4 Π and B 4 Σ – states near 13,500 cm –1 and 20,500 cm –1 , respectively. , These states leave the 4s-like 9σ orbital of CrN vacant and probably correlate diabatically to the Cr + 3d 5 , 6 S g + N – , 2p 4 , 3 P g ion pair limit. Additional ion pair states deriving from the Cr + 3d 4 4s 1 , 6 D g + N – , 2p 4 , 3 P g ion pair limit, approximately 12,000 cm –1 higher in energy, also undoubtedly drop into the region spanned by Figure .…”

“…Indeed, previous spectroscopic work has identified the A 4 Π and B 4 Σ − states near 13,500 cm −1 and 20,500 cm −1 , respectively. 28,29 These states leave the 4s-like 9σ orbital of CrN vacant and probably correlate diabatically to the Cr + 3d 5 , 6 S g + N − , 2p 4 , 3 P g ion pair limit. Additional ion pair states deriving from the Cr + 3d 4 4s 1 , 6 D g + N − , 2p 4 , 3 P g ion pair limit, approximately 12,000 cm −1 higher in energy, also undoubtedly drop into the region spanned by Figure 1.…”