15N NMR spectra and reactivity of 2, 4, 6‐triazidopyridines, 2, 4, 6‐triazidopyrimidine and 2, 4, 6‐triazido‐s‐triazine. (22nd July 2013)

• Record Type: Journal Article
• Authors: Chapyshev, Sergei V.; Ushakov, Evgeny N.; Chernyak, Alexander V.
• Is Part Of: Magnetic resonance in chemistry. Volume 51:Number 9(2013:Sep.)
• Page Start: 562
• Page End: 568
• Publication Date: 2013-07-22
• Subjects: 15N NMR -- DFT calculations -- azido‐s‐triazines -- azidopyrimidines -- azidopyridines -- cross‐linking reagents -- energy materials; Nuclear magnetic resonance spectroscopy -- Periodicals; Chemistry, Organic -- Periodicals; Magnetic resonance -- Periodicals; 538.36
• DOI: 10.1002/mrc.3987
• Languages: English
• ISSNs: 0749-1581

Abstract

Abstract : 2, 4, 6‐Triazido‐s‐triazine, 2, 4, 6‐triazidopyrimidine and six different 2, 4, 6‐triazidopyridines were studied by 15 N NMR spectroscopy. The assignment of signals in the spectra was performed using the gauge‐independent atomic orbital (GIAO)–Tao‐Perdew‐Staroverov‐Scuseria exchange‐correlation functional (TPSS)h/6‐311+G(d, p) calculations on the M06‐2X/6‐311+G(d, p) optimized molecular geometries. The Truhlar and coworkers' continuum solvation model called SMD was applied to treat solvent effects. With this approach, the root mean square error in estimations of the 15 N chemical shifts for the azido groups was just 1.9 ppm. It was shown that the different reactivity of the α ‐ and γ ‐azido groups in pyridines correlates well with the chemical shifts of the N α signals of these groups. Of two nonequivalent azido groups of azines, the azido group with the most shielded N α signal is the most electron‐deficient and reactive toward electron‐rich reagents. By contrast, the azido group of azines with the most deshielded N α signal is the most reactive toward electron‐poor reagents. Copyright © 2013 John Wiley & Sons, Ltd. Abstract : 15 N NMR spectra provide important information about reactivity of nonequivalent azido groups in aromatic polyazides.