Synthesis, spectroscopic and structural studies of new Schiff bases prepared from 3,5- [formula omitted]-salicylaldehyde and heterocyclic amines: X-ray structure of N-(3,5-di- tert-butylsalicylidene)-1-ethylcarboxylato-4-aminopiperidine

Abstract

Two new sterically hindered salicylaldimines, N-(2,2,6,6-tetramethyl-piperidine-4)-3,5- B u 2 t -salicylaldimine ( I) and N-(1-carboxyethyl piperidine-4)-3,5- B u 2 t -salicylaldimine ( II), have been prepared and characterized by IR, UV–vis, 1H NMR, 13C NMR techniques and the structure of II has been examined by X-ray crystallography. No intermolecular H-bonding, π–π stacking or C H⋯π interactions are observed in the structure. The crystal structure the was mainly governed by intermolecular steric repulsions, due to bulky tert-butyl groups and the tendency of salicylaldimine rings to pack in parallel mode forms one-dimensional columns.