Author/Authors :
Danilov، نويسنده , , V.I. and Dailidonis، نويسنده , , V.V. and Hovorun، نويسنده , , D.M. and Kurita، نويسنده , , N. and Murayama، نويسنده , , Y. and Natsume، نويسنده , , T. and Potopalsky، نويسنده , , A.I. and Zaika، نويسنده , , L.A.، نويسنده ,
Abstract :
The stable structures and electronic properties for the berberine cation as well as possible ammonium, carbinol and amino-aldehyde forms of protoberberine salts in the presence of hydroxyl ions were investigated by the B3LYP/6-31G(d,p) and MP2/6-31++G(d,p) methods. The geometry optimizations by both methods lead to the nonplanar propeller-twisted and buckled structure for the all forms. The obtained bond lengths and bond angles agree with the experimental values. The comparison of total energies elucidates that the amino-aldehyde form is the most preferable tautomer in gas phase, while the carbinol form is less stable. The least stable tautomer is the ammonium form.
