Sites of protonation and copper(II)-complexation in protic ionic liquids comprised of N-hexylethylenediaminium cation
2013; Elsevier BV; Volume: 183; Linguagem: Inglês
10.1016/j.molliq.2013.04.002
ISSN1873-3166
AutoresMayu Watanabe, Shinobu Takemura, Sayaka Kawakami, Emi Syouno, Hiromichi Kurosu, Masafumi Harada, Masayasu Iida,
Tópico(s)Analytical Chemistry and Chromatography
ResumoProtonation sites of a chelating mono-protic ionic liquid (PIL) comprising N-hexylethylenediaminium (= HHexen+) depending on the counter anion were studied by 15N and 13C NMR spectroscopy and DFT calculation. In the case of the bis(trifluoromethanesulfonyl) amide (= TFSA−) PIL, the protonation occurred almost at the secondary amine, whereas the protonation occurred preferentially at the primary amine in the trifluoroacetate (= TFA−) PIL. The formation of a chelating copper(II) complex with the cationic unit of the PIL despite the electrostatic repulsion was revealed using the paramagnetic broadenings of the 13C NMR spectra of the PILs.
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