Extended Data Fig. 8: Synthesis of the deuterium-labelled [3]catenane [D_n]-[3]CMM.

By sequentially adding [D₁₆]-CBPQT^2(+•) and CBPQT^2(+•) during the synthesis of [D_n]-[3]CMM, it is able to bias the distribution of the undeuterated CBPQT⁴⁺ rings on the T and BPM units. The [3]catenane [D_n]-[3]CMM¹³⁺ was obtained as a mixture of four isotopologues, including [D₀]-[3]CMM¹³⁺, and [D₃₂]-[3]CMM¹³⁺, in addition to two co-constitutional isomers [D₁₆]-[3]CMM¹³⁺. CuAAC, copper(I)-catalysed azide–alkyne cycloaddition.