Infrared predissociation (IRPD) spectra of Cl-(CH3OH)(1-3)Ar and Cl-(CH3OD)(1-3)Ar were obtained in the OH and CH stretching regions. The use of methanol-d(1) was necessary to distinguish between CH stretches and hydrogen-bonded OH features. The spectra of Cl-(CH3OH)(2-3)Ar show intense features at frequencies lower than the CH stretches, indicating structures with very strong hydrogen bonds. These strong hydrogen bonds arise from structures in which a Cl-center dot center dot center dot center dot methanol ionic hydrogen bond is cooperatively enhanced by the presence of a second shell and, in the case of Cl-(CH3OH)(3)Ar, a third shell methanol. The strongest hydrogen bond is observed in the Cl-(CH3OH)(3)Ar spectrum at 2733 cm(-1), shifted a remarkable -948 cm(-1) from the neutral, gas-phase methanol value. Harmonic, ab initio frequency calculations are not adequate in describing these strong hydrogen bonds. Therefore, we describe a simple computational approach to better approximate the hydrogen bond frequencies. Overall, the results of this study indicate that high-energy isomers are very efficiently trapped using our experimental method of introducing Cl- into neutral, cold methanol-argon clusters.