Experimental excess molar isentropic compressions for six binary systems: (pyridine, 2-methylpyridine or 2,6-dimethylpyridine) + (water or methanol) are correlated with the calculated theoretically association energies of the ROH center dot center dot center dot NA complexes that increase in the order: pyridine < 2-methylpyridine < 2,6-dimethylpyridine. In spite of stronger O-H center dot center dot center dot N bonds, the negative excesses for methanolic systems are smaller than for the aqueous ones. That is mainly because of the aggregation of water-amine complexes due to the O-H center dot center dot center dot O bonds. Differences in partial molar compressions of the amines in water and methanol solvents result most probably from the hydrophobic hydration in aqueous solutions. (C) 2012 Elsevier B. V. All rights reserved.