a product 5 containing only one deuterium rather than two as required by 6. This structure proof is similar to our work on the oxidative coupling of 1, 2, 3, 4-tetrahydrocarbazole to give the corresponding dimer3 and relies on 13C and 2D NMR as well as mass spectrometry of the relevant compounds. In the present case, the deuteriated monomer 2 was prepared by catalytic deuteriation of the known 6-chlore2, 3-diphenylindole (3) 4 in CH30D/KOCH3 ...