Fig. 3: C–N couplings in MeOH/H2O microdroplets and mechanistic investigations.
From: Catalyst-free Ullmann coupling in aqueous microdroplets
a Mass spectrum of 4-bromoaniline-containing MeOH/H2O microdroplets using N2 as the nebulizing gas. b Proposed mechanism for C–N bond formation of 4-bromoaniline in MeOH/H2O microdroplets. c Proposed mechanism for C–C bond formation of para-halogenated aniline (X = Br, I) in MeOH/H2O microdroplets. d Mass spectrum of TEMPO capturing •OH. e Mass spectral intensities of BICA at different TEMPO concentrations. f Mass spectral intensities of 4,4′-diaminobiphenyl at different TEMPO concentrations. Error bars represent the standard deviation of three independent experiments. g Potential energy profiles for N-centered radicals formation with (black trace) and without •OH (blue trace). h Potential energy profiles for C–C coupling (black trace) and C–N coupling (red trace) reaction processes. Potential energy profiles for the reactions were calculated at the (U) B3LYP level of theory.
