Benzenediazonium tetrafluoroborate in DMSO decomposed instantaneously with evolution of nitrogen upon addition of a DMSO solution of sodium nitrite. Orientations and partial rate factors for phenylation of substituted benzenes indicated that not phenyl cation but phenyl radical was produced as an intermediate. Hammett's plots of partial rate factors of meta and para positions yielded good straight lines with ρ m= 0.46 and ρ p= 1.67. Plausible ...
