Full multinuclear magnetic resonance analysis of 2,4‐dinitrofluorobenzene

The complete assignment of the high‐resolution NMR spectra 2,4‐dinitrofluorobenzene was made, including the 1 H, 13 C, 15 N, 17 O and 19 F nuclei. The 13 C, 19 F, 13 C, 1 H, 15 N, 19 F and 15 N, 1 H one‐bond and long‐range coupling constants were determinated and the signs were obtained by means of two‐dimensional correlation spectroscopy: 1 H– 1 H‐COSY, 13 C– 1 H‐COSY, 13 C– 1 H‐COLOC and 1 H– 15 N, 19 F– 15 N and 19 F– 13 C HMQC. The spin–lattice relaxation times of 13 C revealed their anisotropy components and it was evident that the dipole–dipole contribution of fluorine was an efficient mechanism for C‐1 relaxation. The T 1 s of 1 H agreed with the classical description: at low temperature the main contribution is dipole–dipole relaxation and at high temperature the relaxation is dominated by the spin–rotation mechanism. A linear relationship between δ 13 C (exp) and σ C using GIAO (hybrid functional B3LYP) was found. 3 J ( 13 C, 1 H) and the 1 J ( 13 C, 13 C) have a relationship with the delocalization energies estimated by the NBO approach. Copyright © 2002 John Wiley & Sons, Ltd.