Figure 2.

Electrospray ionization mass spectrometry (ESI-MS) analysis following anion exchange of (left, a) a control sample of pentameric circular helicate isotopomers from route C, where aldehydes 1 and 1-D₈ were mixed prior to the addition of amine 4. (b–e) Pentameric circular helicate isotopomers from route D, where aldehydes 1 and 1-D₈ were reacted separately with amine 4 to generate helicates 2 and 2-D₄₀, which were subsequently mixed and held at 60 °C. After (b) 1 day, (c) 3 days, (d) 6 days, and (e) 13 days. (Right, a) Control sample of pentafoil knot isotopomers from route E, where aldehydes 1 and 1-D₈ were mixed prior to the addition of diamine 5. (b–e) Pentafoil knot isotopomers from route F, where aldehydes 1 and 1-D₈ were reacted separately with diamine 5 to generate pentafoil knots 3 and 3-D₄₀, which were subsequently mixed and held at 60 °C. After (b) 1 day, (c) 3 days, (d) 6 days, and (e) 13 days.