H-1, C-13, N-15 NMR and (n)J(C, H) coupling constants investigation of 3-piperidino-propylamine: A combined experimental and theoretical study

Abstract

Proton coupled and decoupled C-13, H-1, N-15, DEPT, COSY, HETCOR and INADEQUATE NMR spectra of 3-piperidino-propylamine (3-pipa) have been reported for the first time. In order to provide a precise structural elucidation, the magnitude of (n)J(C, H) (n = 1, 2, 3) Coupling constants of 3-pipa (C8H18N2) have been determined. Solvent effects on chemical shifts have been investigated by using CDCl3 and DMSO. Molecular mobility of the title molecule has also been investigated by performing C-13 NMR spin-lattice relaxation firm (T-1) measurements. C-13. H-1 and N-15 NMR chemical shifts and (1-3)J(C, H) coupling constants of 3-pipa have been calculated by means of B3LYP density functional method with 6-311 ++G(d,p) basis set. Comparison between the experimental and the theoretical results indicates that density functional B3LYP method is able to provide satisfactory results for predicting NMR properties