The photodissociation of V+ · CH4

The isolated VCH4+ ion has been interrogated via resonant one-photon photodissociation spectroscopy. An electronic transition corresponding to a 3d34s ← 3d4 excitation of the metal center characteristic of electrostatic complexes of V+ is observed. The vibronic structure of the spectrum yields the stretching frequency of the excited state of the complex, 90.0 cm−1, with a diagonal anharmonicity of 0.70 cm−1 as well as a rocking frequency of 44.8 cm−1. The electrostatic binding energy of the excited metal ion (3d34s) to methane is determined to be 2900 ± 300 cm−1, whereas the ground state metal ion (3d4) is bound by 5250 ± 300 cm−1.