The pure rotational spectrum of HPS ($\tilde{\rm X}^1 {\rm A}^{\prime}$X̃1A′): Chemical bonding in second-row elements

Abstract

The pure rotational spectrum of HPS, as well as its (34)S and D isotopologues, has been recorded at microwave, millimeter, and submillimeter wavelengths, the first observation of this molecule in the gas phase. The data were obtained using a combination of millimeter direct absorption, Fourier transform microwave (FTMW), and microwave-microwave double-resonance techniques, which cover the total frequency range from 15 to 419 GHz. Quantum chemical calculations at the B3LYP and CCSD(T) levels were also performed to aid in spectral identification. HPS was created in the direct absorption experiment from a mixture of elemental phosphorus, H(2)S, and Ar carrier gas; DPS was produced by adding D(2). In the FTMW study, these species were generated in a pulsed discharge nozzle from PH(3) and H(2)S or D(2)S, diluted in neon. The spectra recorded for HPS and its isotopologues exhibit clear asymmetric top patterns indicating bent structures; phosphorus hyperfine splittings were also observed in HPS, but not DPS. Analysis of the data yielded rotation, centrifugal distortion, and phosphorus nuclear spin-rotation parameters for the individual species. The r(m) ((1)) structure for HPS, calculated from the rotational constants, is r(H-P) = 1.438(1) Å, r(P-S) = 1.9320(1) Å, and θ(H-P-S) = 101.85(9)°. Empirically correcting for zero-point vibrational effects yields the geometry r(e)(H-P) = 1.4321(2) Å, r(e)(P-S) = 1.9287(1) Å, and θ(e)(H-P-S) = 101.78(1)°, in close agreement with the r(m) ((1)) structure. A small inertial defect was found for HPS indicating a relatively rigid molecule. Based on these data, the bonding in this species is best represented as H-P=S, similar to the first-row analog HNO, as well as HNS and HPO. Therefore, substitution of phosphorus and sulfur for nitrogen and oxygen does not result in a dramatic structural change.

An experimental and theoretical study of the electronic spectrum of HPS, a second row HNO analog

“…The quantities v 0 and A −B were allowed to vary in the regression, while A −B was fixed at the value for HPS (8.531095 cm −1 ) calculated from the rotational constants given in Ref. 8. The results of this analysis are summarized in Table III along with the vibronic assignments which will be discussed later.…”

“…were taken from the analysis of the pure rotational spectrum in Ref. 8; the upper state rotational constants were obtained from an analysis of theà state potential energy surface (PES, vide infra) which yielded the excited state equilibrium structure and vibration-rotational constants. 37 Even when only the B3LYP equilibrium structure was used to calculate the excited state rotational constants, the similarity between the observed and calculated contours was acceptable.…”

“…The derived ground state HPS structure was in good agreement with the more recent experimental structure derived from microwave data. 8 The HPS vibrational frequencies were predicted to be ν 1 (PH stretch) = 2195 cm −1 , ν 2 (bend) = 877 cm −1 , and ν 3 (PS stretch) = 647 cm −1 . Other studies examined the electronic stabilization of the PS group by various substituents, 11 the bonding in the thiophosphoryl group, 12 the dynamics of the isomerization, and H 2 elimination reactions of H 3 PS to form HPS, 13 and the reactions that could form PS, including HPS as an intermediate.…”

“…Other studies examined the electronic stabilization of the PS group by various substituents, 11 the bonding in the thiophosphoryl group, 12 the dynamics of the isomerization, and H 2 elimination reactions of H 3 PS to form HPS, 13 and the reactions that could form PS, including HPS as an intermediate. 14 The most recent and highest level theoretical calculations were those done in connection with the microwave study, 8 in which coupled cluster [CCSD(T)] theory was used to calculate the equilibrium structure, harmonic, and anharmonic force fields, quartic centrifugal distortion constants, nuclear quadrupole coupling constants for DPS, and phosphorus nuclear spin-rotation constants.…”

Isolation and Characterization of the Free Phenylphosphinidene Chalcogenides C6H5P=O and C6H5P=S, the Phosphorous Analogues of Nitrosobenzene and Thionitrosobenzene

“…The spectroscopy and structure of H−P=O has been intensively studied . The heavier congener H−P=S has been detected with neutralization–reionization mass spectrometry and rotational spectroscopy . Only in 2019, CH 3 −P=O was generated and efficiently trapped in argon matrices through photolysis or flash vacuum pyrolysis of methylphosphoryl diazide CH 3 P(O)(N 3 ) 2 …”