GAS-PHASE REACTIONS OF FE+ WITH AROMATIC-COMPOUNDS - MONOSUBSTITUTED BENZENE-DERIVATIVES

This study focuses on the reactions of Fe+ with several monosubstituted benzene derivatives in the gas phase utilizing Fourier transform mass spectrometry techniques and laser desorption generation of iron ions. Generally, the phenyl group is not directly involved in the reactions, although the formation of the benzyne ligand (C6H4) was commonly observed. Only in one case (nitrobenzene) was the benzene C6 skeleton altered and the formation of the C5H5 ligand observed. The initial step in the reactions of the iron ions usually involves insertion into a bond to the most electronegative atom in the substituent group. Insertions into C‒C and C‒H bonds were also observed, and hydrogen or methyl group shifts often preceded bond cleavage. The reactions of a few pentafluorobenzene derivatives were investigated for comparison and were often found to vary greatly from the reactions of the analogous benzene derivative. Lower limits for bond energies were found to be 81 kcal/mol for D°(Fe+‒C6H4), 59 kcal/mol for D°(Fe+‒S), 55 kcal/mol for D°(Fe+‒C6H5OCH3) and D°(Fe+‒C6H5OC2H5), 27.8 kcal/mol for D°(Fe‒C2H4), and 37 kcal/mol for D°(Fe+‒C5H5). © 1990, American Chemical Society. All rights reserved.