FT-IR, Raman, NMR and DFT studies on two bis-aniline derivatives

V. Chiş1, C. Lehene1, M. Venter2, O. Cozar1, M. Vasilescu1, N. Leopold1

1 “Babes-Bolyai” University, Faculty of Physics, Kogalniceanu 1, RO-400084 Cluj-Napoca, Romania.
2 “Babes-Bolyai” University, Faculty of Chemistry and Chemical Engineering, Department of Inorganic Chemistry, Arany Janos 11, Cluj-Napoca, Romania.

Among various applications of the aromatic amines, especially in synthesis chemistry, one of the most important is their use as starting materials for the preparation of diaza- and triazene derivatives. The latest class of compounds is remarkable due to the biological and catalytic properties of the neutral and/or coordinated compounds.1 Moreover, the poly-amino aromatic derivatives may be used as building units in the construction of channel-type supramolecular structures revealing catalytic and separation properties, due to their ability to generate N-HE (E = N, O, S) intermolecular interactions.2
In view of recent interest in this field, we initiated the structural investigation of two bis-aniline derivatives: 4,4'-diaminodiphenylmethane (1) and 4,4'-diaminodiphenylether (2). Due to the presence of two amino groups distanced by large spacers and the overall angular structure of these molecules, the compounds 1 and 2 may be predicted as potential templates for the construction of nanometric cavities.

1						2
Molecular structure of the two investigated bis-aniline derivatives

The aim of this work is to fully characterize the compounds 1 and 2 by FT-IR, FT-Raman and multinuclear (1H and 13C) NMR spectroscopy in conjunction with Density Functional Theory (DFT) calculations, in order to establish the structure and electronic properties of these compounds3. Thus, the experimental vibrational and NMR spectra of these molecules will be assigned and discussed, based on calculations performed at B3LYP and BLYP levels of theory with different basis sets. In addition, emphasis will be put on the intermolecular interactions of these compounds, which could lead to the construction of nanometric cavities. Finally, the reliability of the semiempirical methods AM1 and PM3 will be tested for predicting the molecular properties of these compounds, as fast and computationally feasible methods for the investigation of their supramolecular entities. 

1.	M.M. Venter, PhD Thesis, Babeş-Bolyai University, 1998.
2.	C.N.R. Rao et al, J. Amer. Chem. Soc, 119, 10867, 1997; J. Mater. Chem, 9, 2407, 1999; J. Amer. Chem. Soc, 121, 17521, 1999.
3.	V.Chiş, Chem.Phys., 300, 1, (2004)