Abstract The specific interactions (“complexations”) between N 2 or CO and protic molecules, especially alcohols, are discussed. The influence of the interaction of N 2 and CO on the νOH, δOH, νCO and τOH bands of methanol were studied by recording the i.r. spectrum of methanol in N 2, CO and mixed Ar/N 2 and Ar/CO matrices; shifts of these bands from the argon values were larger in some of the mixed matrices than in pure N 2 or CO. All of these four bands are split by 2% of CO in Ar. The influence of N 2 and CO on the shift of the τOH band from the argon value was found to be smaller for methanol than for other alcohols. In contrast to argon, the τOH band is intense in pure N 2 and CO and is symmetric and considerably temperature dependent, especially in pure CO.