Matrix Isolation and EPR Spectroscopy of Septet 3,5-Difluoropyridyl-2,4,6-trinitrene
摘要:
Septet 3,5-difluoropyridlyl-2,4,6-dinitrene along with quintet 2-azido-3,5-difluoropyridyl-4,6-dinitrene, quintet 4-azido-3,5-difluoropyridyl-2,6-dinitrene, triplet 2,6-diazido-3,5-difluoropyridyl-4-nitrene, and triplet 2,4-diazido-3,5-difluoropyridyl-6-nitrene have been obtained by photolysis of 2,4,6-triazido-3,5-difluoropyridine in solid argon at 4 K. The electronic and magnetic properties of the matrix-isolated nitrenes were studied using electron paramagnetic resonance (EPR) spectroscopy in combination with density functional theory (DFT) calculations. The fine-structure parameters of the nitrenes were determined with high accuracy from computer spectral simulations. All signals in the EPR spectra of the nitrenes randomly oriented in the solid phase were unambiguously assigned on the basis of eigenfield calculations of the Zeeman energy levels and angular dependencies of resonance fields from the direction of the applied magnetic field.
Di- and triazidation of 3-chlorotetrafluoropyridine
摘要:
3-Chlorotetrafluoropyridine and pentafluoropyridine readily react with an excess of sodium azide in dimethylsulfoxide at room temperature to give corresponding 2.4,6-triazido-3-chloro-5-fluoropyridine and 2,4,6-triazido-3,5-difluoropyridine in high yields. The reaction of asymmetric 3-chlorotetrafluorpyridine with two equimolar amounts of sodium azide under similar reaction conditions occurs regioselectively to give 2,4-diazido-5-chloro-3,6-difluoropyridine as a sole product. (19)F, (13)C and (15)N NMR spectral characteristics of the triazides suggest that these compounds can be of interest as cross-linking reagents for polymer chemistry and as starting materials for organic synthesis. (C) 2011 Elsevier B.V. All rights reserved.