Restricted rotations in 4,6-bis- and 2,4,6-tris-(N,N-dialkylamino)-s-triazines

Abstract

Barriers to rotation have been measured in some 4,6-bis- and 2,4,6-tris-(N,N-dialkylamino)-s-triazines. X-Ray crystal structures are reported for 2-chloro-4,6-bis(diisopropylamino)-s-triazine 1,2,4,6-tris(diisopropylamino)-s-triazine 6,2,4,6-tris(diisobutylamino)-s-triazine 8 and the tetrakis(dibutylamino) derivative 12. In the isopropyl compounds 1 and 6, the structures are precisely ordered with all the isopropyl groups in the same direction: the dynamic NMR behaviour is in good agreement and barriers for rotation around the N–Ar and N–C_α bonds in 1 were assigned as 15.6 and 12.1 kcal mol^–1, respectively.