Electron binding to valence and multipole states of molecules: Nitrobenzene, para- and meta-dinitrobenzenes

Abstract

Low-energy photoelectron imaging spectroscopy of nitromethane anions: Electron affinity, vibrational features, anisotropies, and the dipole-bound state J. Chem. Phys. 130, 074307 (2009); 10.1063/1.3076892Effect of excess electron and one water molecule on relative stability of the canonical and zwitterionic tautomers of glycine Nitrobenzene anions (NB Ϫ ) in both valence and dipole bound states are examined using laser ͑photodetachment͒ photoelectron and Rydberg electron transfer ͑RET͒ spectroscopies. Photoelectron spectroscopy of the valence NB Ϫ anion yields a valence ͑adiabatic͒ electron affinity of 1.00Ϯ0.01 eV. The reaction rates for charge transfer between atoms of cesium and xenon in high Rydberg states ͓Cs(ns,nd) and Xe(n f )͔ and NB exhibit a prominent peak in their n-dependencies consistent with the formation of a dipole bound anion having an electron affinity of 28 meV. Para-dinitrobenzene ͑pDNB͒ has a zero dipole moment and a large quadrupole moment. RET studies with pDNB show a complex n-dependence. The rate of formation of pDNB Ϫ ions exhibits a broad peak at low n-values and a second very broad feature extending to large n-values. The peak at low n is tentatively attributed to charge exchange into a quadrupole bound state (EA qb ϭ25 meV). The absence of field-detachment for these ions suggests that if these are in a quadrupole bound state they are strongly coupled to the valence state. Meta-dinitrobenzene ͑mDNB͒ has a large dipole moment and a small quadrupole moment. The observation of a weak but narrow peak at a low n-value in the RET measurement is consistent with electron attachment into a primarily dipole bound state (EA db ϭ68 meV) which is also strongly coupled to the valence state.

The chemistry of nitroso oxides

“…For calibration, the G3MP2B3 AEA of PhNO and PhNO 2 are 1.08 and 0.91 eV, correspondingly. The theoretical value for nitrobenzene is in reasonable agreement with photoelectron spectroscopy experiments, 1.00 ± 0.01 eV 75 .…”

A Drude-model approach to dispersion interactions in dipole-bound anions

“…However this is no longer the case, as they have been found to be important in a variety of chemical processes. The demonstration that dipole-bound anions can serve as precursors to formation of valencelike anions [38][39][40] has generated much interest in their role in electron capture in biological molecules such as uracil and thymine. [41][42][43][44][45][46] In addition, many biologically important molecules can exist as zwitterions, which because of their large dipole moments, can form dipole-bound anions.…”

Electron capture dissociation mass spectrometry of tyrosine nitrated peptides

“…None of the unmodified proteinogenic amino acids have a positive electron affinity. However, it was shown that benzyl modifications of cysteine with an EA of Ն1.00 eV, specifically 3-nitrobenzylcysteine (EA ϭ 1.00 eV [37] and 3,5-dinitrobenzylcysteine (EA ϭ 1.65 eV [38], termed 'electron predators', inhibit peptide backbone cleavage by ECD and the related electron-transfer dissociation (ETD) completely [36]. Identical rates of electron capture were observed for doubly-charged peptides containing modifications with disparate EA suggesting initial electron capture is governed by longrange interactions, i.e., the electron is captured to high-n Rydberg states, as proposed by McLafferty [10].…”