Modification of hydrocarbon sorption properties of cloverite by grafting organotin complexes

The reaction of tetraethyltin with cloverite preliminary dehydroxylated at 450 degrees C was studied by various methods such as H-1 and Sn-119 MAS NMR, C-13 CP-MAS NMR, infrared, chemical analysis of the grafted organometallic fragments and of evolved gases. All techniques are in agreement with the formation of a T-O-SnEt3 (T = P, Ga) surface organometaliic complex grafted inside the crystal structure, with one tin organometallic fragment per aperture of the cages. The resulting material showed adsorption properties highly different from those of the starting material. For example, iso-octane was totally excluded while the adsorption rate of n-hexane was reduced compared to benzene. (C) 1997 Elsevier Science B.V.