First observation and electronic spectroscopy of chromium mononitride: The A 4Πr←X 4Σ− transition near 745 nm

Abstract

We report the first gas phase spectroscopic study of chromium mononitride. CrN molecules were generated in our laser vaporization molecular beam source and studied using laser induced fluorescence techniques. Twelve vibronic subbands of Cr14N have been rotationally analyzed in the 745–647 nm region. These bands are assigned to the A 4Πr←X 4Σ− transition. The assigned ground state electron configuration 1δ29σ1 and symmetry are identical to those of the isovalent VO, MoN, and WN molecules. The energy observed for the excited 4Πr state matches closely the first 4Π state energy derived from a recent ab initio calculation [J. F. Harrison, J. Phys. Chem. 100, 3513 (1996)]. In addition to the A-X transition, 11 other bands of Cr14N have been identified and vibrationally assigned to transitions involving two other excited states, presumably the B4Σ−, and a 2Π state. Comparisons with the isovalent VO, MoN, and WN systems have provided more insights into the bonding and electronic structure of the CrN molecule.

Electronic Spectroscopy of Rhodium Mononitride

“…The molecules of interest were generated in the laser vaporization molecular beam source already successful in producing spectra of CrN, as previously described (12). For RhN, a rotating rhodium rod (5-mm diameter, 99.9% purity; Goodfellow) was used together with a stream of helium-doped 5% with 14 NH 3 and/or 15 NH 3 (99%, Cambridge Isotopes).…”

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

“…The lower state rotational constants of these bands are almost the same, indicating that the state from which these transitions originate is identical for each band. The carrier of these bands is unambiguously assigned as FeN from the rotational constant, the half-integer angular momentum J, and the experiment using 15 14 N is similar to those of the other 3d transition-metal nitrides which have been published previously (6,13,14,18). Figure 1 shows a schematic representation of the observed spectrum of 56 Fe 14 N. Because it is synthesized from the spectra recorded in a lot of separate experiments, the relative intensities compared over wide wavelength ranges are considered to be rough.…”

“…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.…”

Electronic structures of 3d‐metal mononitrides

“…1 For 3d-metal mononitrides, experimental studies were available only for the neutral species. These include mass-spectrometric investigation on ScN, 2 TiN, 2 and VN; 2 near-infrared electronic emission spectra on ScN; 3 electronic spectra on TiN 4,5 and VN; 6 Stark spectra on TiN; 7 laser spectroscopy on TiN; 8 laser-induced fluorescence on VN 9,10 and CrN; 10,11 laser ablation and matrix infrared techniques on VN, 12 CrN, 12 MnN, 12 FeN, 13 CoN, 14 NiN, 14 and MN (MASc, Ti, V, Cr, Mn, Fe, Co, Ni). 15 Theoretical studies on the neutral species include MRCI (multireference configuration interaction) method on ScN, 16 TiN, 17,18 VN, 18,19 CrN, 18,20 FeN, 21 and NiN; 21 complete active space self-consistent field (CASSCF) on FeN; 20 CIPSI (configuration interaction by perturbation of a multiconfiguration wave function selected iteratively) method on ScN 22 and CuN; 23 CCSD(T) (coupled cluster singles doubles noniterative triples) on MN (MASc, Ti, V, Cr); 24 LDA-LCAO (local density functional linear combination of atomic orbitals) on TiN; 25 DFT (density functional theory) study with B3LYP (explanation see the second part) method on VN, 12 CrN, 12 MnN, 12 and FeN; 13 DFT 14,15 and MRSDCIϩQ (multireference single and double excitation configuration interaction with Davidson-type correction), as well as MRCPA (multireference coupled pair approximation) on CoN.…”