NMRSpectroscopy of Azo, Azoxy and Hydrazo Compounds

Abstract

Introduction: Nitrogen NMR Spectroscopy 15 N and 14 N Techniques Nitrogen Shielding in Azo, Azoxy and Hydrazo Compounds Nitrogen Shielding Tensors Spin–Spin Couplings to Nitrogen in Azo, Azoxy and Hydrazo Compounds

Activation of ammonia and hydrazine by electron rich Fe(ii) complexes supported by a dianionic pentadentate ligand platform through a common terminal Fe(iii) amido intermediate

“…S8 ‡ ). 55 This doublet becomes a singlet when 1Ph-14NH3 is employed in the reaction, confirming the assignment as a 15 N–H proton (Fig. S9 ‡ ).…”

“…The 1 H NMR spectrum of the product features three key resonances: two different -t Bu groups in the alkyl region (1.64 and 0.83 ppm), and one deshielded doublet at +17.82 ppm (J = 66.6 Hz) integrating for 1 H and suggesting a 1 J 15N-1H coupling ( Figure S8). 55 This doublet becomes a singlet when 1 Ph -14 NH 3 is employed in the reaction, confirming the assignment as a 15 N-H proton ( Figure S9). The parameters obtained from the Mössbauer spectrum of this species are consistent with a low spin Fe(II) system (δ = 0.29 mm/s and ΔE Q = 0.97 mm/s, Figure S10).…”

“…From the simulation of the multiplet (red spectrum, Figure 5a), the different J values can be obtained. 55 In particular, the 3 J HH of 22.4 Hz is consistent with a trans isomer, and in addition, a N-N bond length of 1.298 Å can be predicted based on the empirical correlation between the 3 J HH value and the N-N bond distance of trans diazene complexes. 51,69 This is supported by the solid-state structure of 4 Tol depicted in Figure 5b.…”