The pure rotational spectrum of CaNH2 and CaND2 (X̃ 2A1): Additional proof of planarity

Abstract

Articles you may be interested inThe rotational spectrum of CuCCH ( X ̃ Σ 1 + ) : A Fourier transform microwave discharge assisted laser ablation spectroscopy and millimeter/submillimeter study Fine structure and hyperfine perturbations in the pure rotational spectrum of the VCl radical in its X Δ 5 r state Molecules in high spin states III: The millimeter/submillimeter-wave spectrum of the MnCl radical (X 7 Σ + )The pure rotational spectrum of CaNH 2 in its X 2 A 1 ground electronic state has been recorded using millimeter/submillimeter direct absorption methods in the frequency range 320-537 GHz as well as that of CaND 2 . The species were created by Broida-oven techniques. Eleven rotational transitions were observed arising from the vϭ0 and v 6 ϭ1 states of CaNH 2 , and eight transitions were recorded for the v 3 ϭ1 and v 4 ϭ1 levels. For CaND 2 , eight transitions (vϭ0) were also measured. For the majority of these transitions, K a doublets corresponding to K a ϭ0 -5 were observed and fine structure splittings were resolved in every component. These spectra were analyzed using an S-reduced Hamiltonian; rotational, centrifugal distortion, and spin-rotation parameters were determined for CaNH 2 , CaND 2 , and the three observed vibrationally excited states. An r 0 structure has also been calculated. The data are consistent with calcium amide being a planar molecule with C 2v symmetry and having predominately ionic bonding, as indicated by previous optical studies.

Molecular Asymmetry and Optical Cycling: Laser Cooling Asymmetric Top Molecules

“…At first order in perturbation theory, the admixed amplitude will be ζ ∼ αα /4B α , where α = a, b, c labels the principal axes. Typical values of ζ ≈ 1 − 5 × 10 −3 [58,155]. Such mix-ing will present a relevant loss channel after scattering 5 × 10 4 photons, more than required for typical laser cooling.…”

Competition between Metal-Amido and Metal-Imido Chemistries in the Alkaline Earth Series: An Experimental and Theoretical Study of BaNH

“…Because magnesium, calcium, and strontium all produced amide radicals with X ˜2A 1 ground states on reaction with NH 3 , the same product was expected for barium, namely BaNH 2 . [6][7][8] The ground state of this molecule is 2 A 1 , and thus an asymmetric top spectrum with a spin-rotation splitting near 70 MHz 18 should have been observed. However, no asymmetric top pattern consisting of doublets was detectable in the data.…”

“…Gas-phase spectroscopy studies to this point have suggested that both alkali and alkaline earth metals preferentially form the amide species MNH 2 on reacting with ammonia in a dc discharge. [4][5][6][7][8] For example, both NaNH 2 and LiNH 2 have been successfully produced in the gas phase, and their rotational spectra have shown that these are planar species with a 1 A 1 ground electronic state. 4,5 Magnesium, calcium, and strontium amides have been investigated as well, by both optical and pure rotational spectroscopy.…”

“…4,5 Magnesium, calcium, and strontium amides have been investigated as well, by both optical and pure rotational spectroscopy. [6][7][8][9][10] These molecules have proven to be radicals with 2 A 1 ground electronic states; i.e., they are planar with C 2V symmetry. Another possible geometry for the amides is pyramidal; however such structures have not been found for these species.…”

Rotational analysis of the transition of SrNH2

“…For strontium amide, theà 2 B 2 -X 2 A 1 and B 2 B 1 -X 2 A 1 transitions have been rotationally analyzed using high resolution laser spectroscopy, while thẽ C 2 A 1 -X 2 A 1 transition has been observed only at low resolution [12]. Finally, the pure rotational spectra of magnesium, calcium, and strontium amides have been recorded along with their deuterium isotopologues [13][14][15][16]. Again, each species was found to be planar and an r 0 structure was determined in the ground state.…”