BROAD-LINE H-1-NMR - A NEW APPLICATION FOR STUDYING THE BRONSTED ACIDSTRENGTH OF SOLIDS

The Bronsted acidity of solids denoted S is determined by studying the interaction SOH + H2O --> SOH...OH2 --> SO- + H3O+. The concentration s and the internal H-H distances of the species H3O+, H2O...HO, and of the remaining species (OH and H2O) are determined by fitting the 4 K H-1 broad-line NMR spectra of these solids which contain as many water molecules as Bronsted acid sites. An acidity scale is derived from th is determination.