Isolation of the Phenyl Cation in a Solid Argon Matrix

Vacuum UV photolysis of halobenzenes 1 results in the formation of the phenyl cation (2), which is isolated in solid argon matrices. The structure and ground-state multiplicity of 2 were unequivocally determined by IR spectroscopy in combination with isotopic labeling experiments and comparisons with DFT calculations. Furthermore, 2 can be captured by N2 to form the benzene diazonium ion.