THE EXCHANGE PROCESSES IN O-VANILLIN SALICYLOYLHYDRAZONE AS STUDIED BY 2-DIMENSIONAL NMR

Multidimensional NMR studies of o-vanillin salicyloylhydrazone at vari ous temperatures have been undertaken in deuterated dimethyl sulfoxide and its cryoprotective mixture in H2O and D2O, acetone and acetonitri le. The molecule is found to exist in two conformers in dimethyl sulfo xide and the cryoprotective mixture. The exchange between the two conf ormers has been detected from the two-dimensional experiments - inform ation which is not easily obtainable from the normal one-dimensional s pectra. Results in the different solvents are interpreted in terms of solvent-solute interactions.