title: High-resolution infrared spectroscopy of the charge-transfer complex [Ar-N2]+: a combined experimental/theoretical study.
abstract: A combined experimental and theoretical study of the charge-transfer complex [Ar-N(2)](+) is presented. Nearly 50 transitions split by spin-rotation interaction have been observed by means of infrared diode laser absorption spectroscopy in a supersonic planar plasma expansion. The band origin is at 2272.2563(18) cm(-1) and rotational constants in the ground and vibrationally (NN-stretch) excited state amount to 0.128701(8) cm(-1) and 0.128203(8) cm(-1), respectively. The interpretation of the data in terms of a charge switch upon complexation is supported by new ab initio calculations. The best estimate for a linear equilibrium structure yields R(e)(NN)=1.102 A and R(e)(Ar-N)=2.190 A. Predictions for molecular parameters not directly available from the experimental results are presented as well. Furthermore, the electronic structure and Ar-N bonding mechanism of [Ar-N(2)](+) have been analyzed in detail. The Ar-N bond is a textbook example of a classical 2-center-3-electron bond.
authors.affiliation: Laser Centre Amsterdam, Department of Physical Chemistry, Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Verbraak
authors.forename: J N P
authors.initials: JN
authors.lastname: van Stralen
authors.forename: J
authors.initials: J
authors.lastname: Bouwman
authors.forename: J S
authors.initials: JS
authors.lastname: de Klerk
authors.forename: D
authors.initials: D
authors.lastname: Verdes
authors.forename: H
authors.initials: H
authors.lastname: Linnartz
authors.forename: F M
authors.initials: FM
authors.lastname: Bickelhaupt