Laser photodetachment determination of the electron affinities of OH, NH2, NH, SO2, and S2

Using a fixed frequency argon ion laser we have studied the energy spectra of electrons photodetached from OH⁻, ${\mathrm{NH}}_2^{-}$ , NH⁻, ${\mathrm{SO}}_2^{-}$ , and ${\mathrm{S}}_2^{-}$ . We determined the following electron affinities: $E_A(\mathrm{OH}{\text{)= 1.829}}_{\text{−0.014}}^{\text{+0.010}}\hspace{0.17em}\mathrm{eV}$ , E_A(NH₂)=0.779±0.037 eV, E_A(NH)=0.38±0.03 eV, E_A(SO₂)=1.097±0.036 eV, and E_A(S₂)=1.663±0.040 eV. Additionally, the angular distribution anisotropy parameter β was measured for OH⁻ and ${\mathrm{NH}}_2^{-}$ at 4880 Å, as −0.993 ± 0.040, and 0.027±0.012, respectively, and information about negative ion vibrational constants is presented.