THEORETICAL-STUDY OF THE STRUCTURE AND TAUTOMERISM OF N-1-UNSUBSTITUTED PYRAZOLES IN THE SOLID-STATE

Ab initio theoretical calculations have been performed on the pyrazole cyclic dimer, trimer and tetramers as well as on linear oligomers, as suming that there is no relaxation of the geometry during the proton t ransfer, The ground state and a wide variety of transition states, cor responding to different pathways for intermolecular proton transfer,ha ve been explored and the results compared with experimental data from crystallography and solid state NMR spectroscopy, For the simplest cas e of the dimer, the reaction path corresponding to a double proton tra nsfer has been explored as well as the effect of relaxing the geometry .