Synthesis, spectroscopy and structure of diiodofuroxan
摘要:
Diiodofuroxan (3,4-diiodo-1,2,5-oxadiazole 2-oxide) has been investigated for the first time in the gas phase by UV photoelectron spectroscopy, and in the solid phase by mid-infrared and Raman spectroscopy. The individual spectroscopies provide a detailed investigation into the vibrational and electronic character of the molecule, and are supported by quantum-chemical calculations. The molecule is confirmed by calculations at the B3LYP and CCSD(T) levels as a planar five-membered ring with a strong exocyclic and a relatively weak endocyclic N-O bond. Diiodofuroxan, upon thermolysis, does not cleave to the ICNO monomer, but leads to the formation of ONCCNO and iodine. (C) 2010 Elsevier B.V. All rights reserved.
The mechanism and selectivity of cycloaddition reactions of iodonitrile oxide, ICNO, have been studied with theoretical methods for the first time using MR-AQCC coupled-cluster and B3LYP DFT methods. Calculations have predicted that the favoured ICNO dimerisation process is a multi-step reaction to diiodofuroxan involving dinitrosoethylene-like intermediates. The ICNO cycloaddition with nitriles and