Photoelectron–photofragment coincidence studies of NO−-X clusters (X = H2O, CD4)

Abstract

The dissociative photodetachment of NO⁻(H₂O)and NO⁻(CD₄) anion clusters was studied at 775 nm (1.60 eV) using photoelectron–photofragment coincidence spectroscopy. The correlation between the photoelectron and photodetached neutral spectra indicates vibrational excitation in the recoiling NO neutral fragments from NO-(H₂O), with a progression consistent with vibrational excitation up to v(NO) = 3 in the products. The correlation remains when D₂O is substituted for H₂O, implying the NO vibrational mode plays a role in the dissociation coordinate of the complex. In contrast, no correlation was observed between photoelectron kinetic energy and kinetic energy release from NO⁻(CD₄). Consideration of the maximum available kinetic energy allows the binding energies to be detemined as 0.57 and 0.07 eV for NO⁻(H₂O) and NO⁻(CD₄), respectively.