The ENDOR crystallography of disordered systems used for studying the
electronic and geometric structure of some copper(II) sulfur containin
g chelate complexes and oxovanadium(II) chelate complexes in solid sta
te and in frozen solution is reported. This method is also applied for
studying some very weak interactions in solution between the cited ch
elate complexes and different solvents (alcohol, chloroform) which are
unaccessible with other physical methods.