Neutral and ionic multiple hydrogen bonded moieties in crystal structure of a one tripodal Schiff base

摘要

Structural and spectroscopic properties of solid tris(3-formyl-5-methyl-2-salicylidenamino-ethyl)amine have been investigated. This is a compound containing two moieties with triple Schiff base fragments. One of the moieties has all three neutral intramolecular O-H ... N hydrogen bonds, whereas there are only ionic H-bonds in the other moiety. Both moieties form cavities with the amine N atom lone electron pairs inside strongly shielded by three aliphatic wings. The H-bond formed in the Schiff fragments influence the other structural parameters of the nearest aromatic parts of the moieties. C-13 and N-15 CP/MAS NMR results (chemical shifts) allow to identify two pairs of Schiff and amino nitrogen nuclei thus supporting formation of the two types of moieties in the crystal lattice. (C) 2003 Elsevier B.V. All rights reserved.