The vibrational spectra of molecular ions isolated in solid neon. V. N2O+ and NNO−2

Weak covalent interactions and anionic charge-sharing polymerisation in cluster environments

We discuss the formation of weak covalent bonds leading to anionic charge-sharing dimerisation or polymerisation in microscopic cluster environments. The covalent bonding between cluster building blocks is described in terms of coherent charge sharing, conceptualised using a coupled-monomers molecular-orbital model. The model assumes first-order separability of the inter- and intra-monomer bonding structures. Combined with a Hückel-style formalism adapted to weak covalent and solvation interactions, it offers insight into the competition between the two types of forces and illuminates the properties of the inter-monomer orbitals responsible for charge-sharing dimerisation and polymerisation. Under typical conditions, the cumulative effect of solvation obstructs the polymerisation, limiting the size of covalently bound core anions.

Infrared spectroscopic studies on the cluster size dependence of charge carrier structure in nitrous oxide cluster anions

We report infrared photodissociation spectra of nitrous oxide cluster anions of the form (N2O)(n)O(-) (n = 1-12) and (N2O)n(-) (n = 7-15) in the region 800-1600 cm(-1). The charge carriers in these ions are NNO2(-) and O(-) for (N2O)(n)O(-) clusters with a solvation induced core ion switch, and N2O(-) for (N2O)n(-) clusters. The N-N and N-O stretching vibrations of N2O(-) (solvated by N2O) are reported for the first time, and they are found at (1595 ± 3) cm(-1) and (894 ± 5) cm(-1), respectively. We interpret our infrared spectra by comparison with the existing photoelectron spectroscopy data and with computational data in the framework of density functional theory.

Infrared spectra of NH2NO, NH2NO+, and NNOH+ and of the N2⋯H2O complex trapped in solid neon

When a Ne:H2:N2O mixture is co-deposited at 4.3 K with a beam of neon atoms that have been excited in a microwave discharge, NH2NO+ is stabilized in sufficient concentration for detection of five of its vibrational fundamentals. Their assignments are supported by isotopic substitution studies and by the results of unrestricted B3LYP/cc-pVTZ calculations. Electron recombination results in the stabilization of NH2NO, for which the previously reported argon-matrix assignments are confirmed and extended. The OH-stretching fundamental of NNOH+ also is present in the spectrum of the initial sample deposit, but because of proton sharing with the neon matrix is shifted 43.3 cm(-1) from the gas-phase band center. The OD-stretching fundamental of NNOD+ is identified for the first time in the present study. An absorption at 2311.1 cm(-1) is contributed by the NN-stretching vibration of a complex of N2, probably with an ionic species. On prolonged visible and near-ultraviolet irradiation of the deposit, absorptions of the binary N2...H2O complex become increasingly prominent.