Infrared spectra of I-.(CH3OH)(n).Ar-m, n=1,2 clusters, obtained via argon and methanol predissociation, are interpreted with the aid of ab initio calculations of the OH stretching fundamentals. The spectra of the cold, argon-solvated clusters establish the coexistence of two isomeric forms of the n=2 cluster, with the asymmetric isomer displaying a dramatic (similar to150 cm(-1)) OH red-shift relative to both the symmetric isomer and the n=1 complex. We trace this red-shift to cooperative H-bonding which is only operative in the asymmetric form. At the higher internal energies afforded by the bare (i.e., Ar-free) complexes, the spectra are radically changed. The strongly red-shifted band is suppressed, reflecting the loss of the cooperative effect as the methanol molecules are separated, while the bands assigned to the more open form are enhanced.