TAUTOMERISM IN 2,2'-BIPYRIDYL-3,3'-DIOL

摘要

Three stable tautomeric forms, dienol (DE), ketoenol (KE), and diketo (DK), of 2,2'-bipyridyl-3,3'-diol BP(OH)(2) were found in this study, using the semiempirical AM1 and MNDO-PM3 and ab initio (4-31G basis set) methods. All calculations were carried out without any symmetry restrictions. There is a good agreement between the ab initio calculated and experimentally obtained structural parameters for the DE tautomer. Transition structures, corresponding to the DK double right arrow KE and KE double right arrow DE processes have also been found. On the basis of the results from the present work, an asynchronous (two-step) DK double right arrow KE double right arrow DE mechanism of the IPT reaction in BP(OH)(2) is proposed. (C) 1996 John Wiley & Sons, Inc. [References: 45]