RELATIVE LOG-P AND SOLUTION STRUCTURE FOR SMALL ORGANIC SOLUTES IN THE CHLOROFORM WATER-SYSTEM USING MONTE-CARLO METHODS

Relative log P values of dimethylether to methanol and dimethylamine to methylamine were calculated in the chloroform/water system using Monte Carlo simulations and statistical perturbation theory. Correct ordering of the calculated relative log Ps was obtained for the two pairs although the method leads to an overestimation of these values. In aqueous solution, both dimethyl ether and dimethylamine solutes are proton acceptors forming a single hydrogen bond to water. Dimethylamine forms a stable N-H-Ow hydrogen bond while the water hydrogen is poorly localized in the O-H-Ow bond to the ether. In chloroform, the solvent molecules are less ordered around the solutes than was found around methanol and methylamine.