Isomere und tautomere Formen substituierter 1.5-Diphenyl-3-phenylcarbamoylformazane / Isomeric and Tautomeric Forms of Substituted 1,5-Diphenyl-3-phenylcarbamoylformazanes

Abstract

The coupling of aryldiazonium salts to malonanilic acid gives formazanes with a phenylcarbamoyl group attached to the C-atom. One of these compounds has been 15N-labelled. IR and NMR spectroscopic investigations show that the formazanes exist in the solid state and in solution as mono- and bischelated isomers. The influence of solvents on the rate of isomers and on the chemical shifts has been examined. Approximately linear relationships are given between the δ-values of NH-protons, parameters ET and Hammett σ-values.