Knowledge Bank

We have studied the $SH(2\Pi ,)-Ar$ and SD-Ar radical complexes with FTMW spectroscopy. The complexes were produced in a supersonic free jet by a pulsed discharge of $H2S$ or $D2S$, which was diluted to 0.35% in Ar with a stagnation pressure of 2 atm. R-branch transitions in the lower spin-orbit component ($\Omega =3/2$) for the linear $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi i$ radicals were observed for $J\prime \prime =3/2$ to $J\prime \prime =15/2$ in the 8 - 26 GHz region. The transitions were split into two parity components owing to the parity doubling. Each parity component was split further due to the magnetic hyperfine interaction associated with the H/D nucleus. Rotational constants for SH-Ar and SD-Ar were determined to be 1569,656(2) and 1567.707(2)MHz respectively. The value for SH-Ar agrees well with that, of a previous LIF $study.a$ From the SH/SD data. it was confirmed that the argon atom is located at the hydrogen side of the SH radical. With an assumption that the S-H band length is equal to that in the monomer, the H-Ar distance is calculated to be 2,900 \AA, which is about, 0.1 \AA longer than that in OH-Ar. The effective $Ds$ constants of SH-Ar and SD-Ar were found to have negative values of $-58.4(7)$ and $-50.7(6)$ kHz respectively.