- The interacting B 4Σ- and d 2Π states of CrN: A laser induced and dispersed fluorescence study
-
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 4Σ- ← X 4Σ-, d 2Π3/2←X 4Σ-, and d 2Π1/2←X 4Σ-, have been rotationally analyzed. Perturbations between the B 4Σ- and d 2Π states and their dependence on vibrational quantum numbers have been examined. Dispersed fluorescence (DF) 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 T～6000 cm-1, identified as the a 2Σ- state. Molecular parameters in the B 4Σ-, d 2Π, and a 2Σ- states have been established.
- Zhou, Chi,Balfour, Walter J.,Qian, Charles X. W.
-
-
Read Online
- First observation and electronic spectroscopy of chromium mononitride: The a 4Πr←X 4Σ- transition near 745 nm
-
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 1 δ29σ1 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.
- Balfour, Walter J.,Qian, Charles X. W.,Zhou, Chi
-
-
Read Online
- The permanent electric dipole moments of chromium and vanadium mononitride: CrN and VN
-
The Pe(1), F = 2.5 branch feature of the (0,0) D 3Π0e - X 3Δ1 band system of 51 VN was recorded as a function of an applied static electric field. The resultant Stark splitting and shifts were analyzed giving values of 3.07(7) D and 6.1(4) D for the X 3Δ1 and D 3Π0e states, respectively, for the magnitude of the permanent electric dipole moment, μ. Similarly, the Ree(0.5) branch feature of the (0,0) A 4Π3/2 - X 4Σ- band system of 52 CrN was recorded as a function of an applied static electric field and analyzed to produce μ values of 2.31(4) D and 5.42(2) D for the X 4Σ- and A 4Π3/2 states, respectively. In order to facilitate the dipole moment determinations for 52CrN it was necessary to record and analyze the field free spectrum of the (0,0) A 4Π3/2 - X 4Σ- subband system. A comparison of the dipole moments for the first row monoxides and mononitrides is made and trends are discussed with reference to a molecular orbital correlation scheme.
- Steimle, Timothy C.,Robinson, J. Scott,Goodridge, Damian
-
-
Read Online
- Infrared spectra, structure, and bonding of the group 6 and ammonia M:NH3, H2N-MH, and N≡MH3 reaction products in solid argon
-
Laser-ablated chromium, molybdenum, and tungsten atoms undergo oxidative addition reactions with ammonia during condensation in excess argon. The subject molecules were trapped in solid argon and identified by isotopic shifts and DFT frequency calculations. The 1:1 metal-ammonia complexes increased on annealing and photoisomerized to H2N-MH and then to N≡MoHj and N=WH 3, but N≡CrH3 is too high in energy to be formed here. These products also increased slightly on annealing, which indicates a spontaneous reaction between group 6 metal atoms and ammonia. The N≡MoH3 and N≡WH3 molecules contain fully developed triple bonds with effective bond orders of 2.91 and 2.92, computed using the B3LYP density functional, and terminal metal nitride bond lengths, in agreement with those measured for larger organometallic complexes.
- Wang, Xuefeng,Andrews, Lester
-
p. 4885 - 4891
(2009/03/12)
-
