Study of Cyclic Quaternary Ammonium Bromides by B3LYP Calculations, NMR and FTIR Spectroscopies

Study of cyclic quaternary ammonium bromides by B3LYP calculations, NMR and FTIR spectroscopies.

N,N-dioctyl-azepanium, -piperidinium and -pyrrolidinium bromides 1-3, have been obtained and characterized by FTIR and NMR spectroscopy. DFT calculations have also been carried out. The optimized bond lengths, bond angles and torsion angles calculated by B3LYP/6-31G(d,p) approach have been presented. Both FTIR and Raman spectra of 1-3 are consistent with the calculated structures in the gas pha...

B3LYP calculations of cerium oxides.

In this paper we evaluate the performance of density functional theory with the B3LYP functional for calculations on ceria (CeO(2)) and cerium sesquioxide (Ce(2)O(3)). We demonstrate that B3LYP is able to describe CeO(2) and Ce(2)O(3) reasonably well. When compared to other functionals, B3LYP performs slightly better than the hybrid functional PBE0 for the electronic properties but slightly wor...

Computational and NMR study of quaternary ammonium ion conformations in solution

Conformations around C–N bonds at the quaternary centre in tetraalkylammonium ions in water solution are investigated. Structures of Me4N , Et4N , n-Pr4N , n-Bu4N , and n-Pe4N + are calculated using quantum mechanical HF and DFT methods together with the PCM solvent model. Relative solvation free energies of tetraalkylammonium ions are further estimated from microscopic molecular dynamics free ...

Synthesis and characterization of alkylammonium zwitterionic amino acids derivatives by FTIR, NMR spectroscopy and DFT calculations.

3-(3-Dimethylammonio)propylammonio propanoate bromide (1), 4-(3-dimethylammonio)propylammonio butanoate bromide (2), and 5-(3-dimethylammonio)propylammonio pentanoate bromide (3) have been obtained in reaction of 1,1-dimethyl-1,3-propylenediamine with 3-bromopropionic acid, ethyl 4-bromobutyrate and 5-bromovaleric acid, respectively. The products have been characterized by FTIR, Raman and NMR s...

Testing quaternary ammonium germicides.