Bob Grimminger, Jie Wei, Blaine Ellis, and Dennis J. Clouthier Department of Chemistry, University of Kentucky, Lexington, KY Zhong Wang, and Trevor Sears Department of Chemistry, Brookhaven National Lab, Upton, NY Discovery of the Electronic Spectra of HPS and DPS

Interests in HPS Possible interstellar species Similarity to the isovalent analogs HNO and HPO Electronic spectrum was previously unknown Little other experimental work done on HPS Os complex (Bohle et al., 1990) Neutralization-reionization (Wong et al., 1992) Microwave spectrum (Halfen et al., Session FC05, Friday morning) 2

What we expect to find 3 Ground state configuration: …(11a ′ ) 2 (12a ′ ) 2 (3a ′′ ) 2 (13a ′ ) 2 (4a ′′ ) 0 X 1 A ′ Promotion of an electron: …(11a ′ ) 2 (12a ′ ) 2 (3a ′′ ) 2 (13a ′ ) 1 (4a ′′ ) 1 A 1 A ′′ Out of plane polarized c-type bands Very spread out rotational structure a b c ~ ~

Production of jet-cooled radicals H 2 S + PH 3 + Ar 4

Bend P-S Stretch Observed LIF spectrum of HPS VibrationObservedTheory † ν 1 (P-H stretch) ν 2 (bend) 661.5(8)642.6 ν 3 (P-S stretch) 502.4(7) † B3LYP/aug-cc-pVTZ 5 * * * *

Observed DPS LIF bands P-S Stretch VibrationObservedTheory † ν 1 (P-H stretch) ν 2 (bend) ν 3 (P-S stretch) 505(1)521.0 † B3LYP/aug-cc-pVTZ 6 ** *

SVL emission from HPS Only bend (673 cm -1 ) and P-S stretch (885 cm -1 ) observed Splitting ≈ 34 cm cm -1 (687 cm -1 ) 885 cm -1 (900 cm -1 ) 7 *B3LYP/aug-cc-pVTZ Ka ′′ = 0 Ka ′ = 1 Ka ′′ = 0 Ka ′′ = 1 Ka ′′ = 2 X(0,0,0) X(0,1,0) A ~ ~ ~

Rotational structure of HPS Observed Theory 8 B3LYP/aug-cc-pVTZ DPS

Where are we in the spectrum of HPS? 9

Collaboration with Sears Group Several new vibronic bands detected All bands were fairly weak 10 P-S stretch

Calculated geometries CoordinateGround StateExcited State P-H (Å) P-S (Å) H-P-S (degrees) B3LYP/aug-cc-pVTZ 11 Walsh, A. D., J. Chem. Soc., 1953, 2289.

CCSD(T)/aug-cc-pVTZ Calculated Walsh-type diagram for HPS 12 HPS ground state orbitals HPS excited state α-orbitals

Future work Extend the electronic spectrum to longer wavelengths Obtain rotationally resolved LIF spectra to determine molecular structure 13