The effects of organic solvents (dimethylsulfoxide-d(6) (DMSO-d(6)), chloroform-d, acetone-d(6), and acetonitrile-d(3)) on the properties of interfacial water at surfaces of silica gel Si-40 and partially silylated fumed silica A-380 were studied by means of the H-1 NMR spectroscopy with freezing-out of adsorbed water at 180 < T < 273 K. The results of the H-1 NMR investigations were also analysed on the basis of the structural characteristics of silicas and quantum chemical calculations of the chemical Shifts delta(H) and solvent effects. DMSO-d(6) and acetonitrile-d(3) are poorly miscible with water in silica gel pores in contrast to the bulk liquids. DMSO-d(6) and chloroform-d affect the structure of the interfacial water weaker than acetone-d(6) and acetonitrile-d(3) at amounts of liquids greater than the pore volume. Acetone-d(6) and acetonitrile-d(3) can displace water from pores under this condition. The chemical shift of protons in water adsorbed on silica gel is 3.5-6.5 ppm, which corresponds to the formation of two to four hydrogen bonds per molecule. Water adsorbed on partially silylated fumed silica has two H-1 NMR signals at 5 and 1.1-1.7 ppm related to different structures (droplets and small clusters) of the interfacial water. (C) 2004 Elsevier B.V. All rights reserved.