The vibrational spectra of molecular ions isolated in solid neon. III. N+4

Abstract

When a Ne:N2=100 or 200 mixture is codeposited at 5 K with a beam of neon atoms excited by a microwave discharge, a weak to moderately intense infrared absorption appears at 2237.6 cm−1 which is assigned to the N+4 molecular ion. The analysis of the infrared spectra of the nitrogen-15 substituted species of N+4 supports the conclusion from earlier ab initio calculations and electron spin resonance observations that N+4 has a linear, centrosymmetric ground-state structure. For the N+4 species with noncentrosymmetric isotopic substitution, the in-phase end-atom stretching fundamental becomes infrared active and has also been observed. Although the anion responsible for overall charge neutrality of the deposit has not been definitively identified, secondary photolysis studies provide some information regarding its properties.