Low-energy photoelectron imaging spectroscopy of nitromethane anions: Electron affinity, vibrational features, anisotropies, and the dipole-bound state

We present low-energy velocity map photoelectron imaging results for nitromethane anions. The photoelectron spectrum is interpreted with the aid of ab initio theory and Franck-Condon factor calculations. We obtain a new value for the adiabatic electron affinity of nitromethane of (172+/-6) meV and observe the dipole-bound state of nitromethane. The photoelectron angular distributions of the observed features are discussed in the context of threshold laws for photodetachment.