19F, 14N and 15N NMR spectroscopic studies on triazadienyl fluoride, N3F

✍ Scribed by Gabriele Schatte; Helge Willner; Monika Willert-Porada

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 456 KB
• Volume: 30
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260300205

✦ Synopsis

Abstract

The results of ^19^F, ^14^N and ^15^N NMR measurements for all ^14^N/^15^N isotopomers of N~3~F in CD~2~Cl~2~ solution are reported. Substantial deshielding for the N‐α and N‐γ atoms, relative to other covalent azides XN~3~ (X  Cl, H, CF~3~, etc.), is observed. The coupling constants also indicate unusual bonding in N~3~F. ^1^J(^15^N‐α, F) and ^3^J(^15^N‐γ, F) are similar (58.2 and 58.6 Hz, respectively), very small for a ^1^J(^15^NF) but very large for a ^3^J(^15^NF) value. The observed value of 26.5 Hz for ^1^J(^15^N‐α ^15^N‐β) is the largest, and ^2^J(^15^N‐α ^15^N‐γ) (5.3 Hz) is the first reported coupling constant for an azide. The unusual N~3~F NMR data are discussed in terms of calculated atomic charges and the influence of the paramagnetic term which dominates the chemical shifts. This term expresses the deshielding due to the circulation of electrons in the magnetic field between the HOMOs and the LUMOs.