Benzamidoximes: structural, conformational and spectroscopic studies. I

Abstract

The synthesis and properties of seven arylamidoximes are reported. 1H- and 13C-NMR studies and MO calculations were performed on all seven and an X-ray crystallographic determination was done on one, to determine their structure. The theoretical calculations were done using the AM1 and PM3 methods. From these results it is concluded that, for all of the arylamidoximes studied here, the NH 2 group of the amidoxime ( N-hydroxyamidine) has very little sp 2 character and the aryl ring is not coplanar with the amidoxime group. X-ray crystallographic data for p-chlorobenzamidoxime were compared with the theoretically calculated coordinates. It is interesting to note that, in crystals, the –NH 2 group is coplanar with the CN bond and the aryl ring is out of the plane of the amidoxime group. Molecular mechanics (Biosym) calculations on benzamidoxime yielded better coordinates than either the AM1 or PM3 methods. © 1997 Elsevier Science B.V.