Spectroscopic and theoretical study in substituted N-phenoxyethylanilines

MIRTA FINAZZI; ROSANA PIVOSO; NÉSTOR E. MAZA; ALICIA H. JUBERT; GUSTAVO ROMANELLI; JORGE JIOS; JUAN CARLOS AUTINO

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2003 vol. 64 p. 443 - 453

0022-3697

Infrared spectroscopicstudies, assigned with the aid of density functional calculations, and ab initio theoretical calculations of N-(2-phenoxyethyl)aniline and their derivatives allow us to have an insight into the vibrational, geometrical and electronic properties of N-(2-phenoxyethyl)aniline, N-(2-(4-nitrophenoxy)ethyl)aniline, 4-methoxy-N-(2-(4-chlorophenoxy)ethyl) aniline, 4-methoxy-N-(2-(2-nitrophenoxy)ethyl)aniline and 4-bromo-N-(2-(2-bromo-4-chlorophenoxy)ethyl)aniline. Our calculations indicate that the gauche conformation around the (CH2)2 chain is the lowest-energy for all the molecules. We further investigated the vibrational behavior of N-(2-phenoxyethyl)aniline, N-(2-(4-nitrophenoxyethyl)aniline and 4-methoxy-N-(2-(4-chlorophenoxy)ethyl)aniline compounds at 300 and 77 K where several peaks corresponding to normal modes associated with the lineal chain showed reinforcement and loosening of their force constants. The peak corresponding to N?H stretching mode has been found dependent on their position and intensity upon the substituents and derivatives. We find that the splitting at 3413?3381 and 3403?3374 cm−1 of the N?H band in the spectra of the NO2 derivatives cannot be associated with the existence of a conformational equilibrium, but may be assigned to a free N?H and to a NH⋯O bonded form, respectively. An analysis of the Mulliken charges on the atoms that constitute the aliphatic chain of the different compounds shows a difference on the acidic capacity of the hydrogen atom attached to the nitrogen atom.