The phenoxyl radical 1 was generated in high yields by flash vacuum pyrolysis of ally! phenyl ether 2 with subsequent trapping of the products in argon at 3 K. In water-doped argon matrices, an OH center dot center dot center dot O complex between 1 and water is formed that could be characterized by IR spectroscopy. Several isotopomers of the complex were generated, and the IR spectra compared to results of density functional theory calculations. Other dimers between 1 and water were not found under these conditions. QM/MM calculations in simulated argon matrices reveal that an OH center dot center dot center dot pi complex is unstable even at a time scale of picoseconds. This finding has implications on the related interaction between the tyrosyl radical and the water in biological systems.