Molecular models of low-energy conformers of macrocycles 9a–c, 10a,b, and 11a–d. The macrocycles were modeled as simplified homologues 9a'–c', 10a',b', and 11a'–d' in which the propyloxyammonium side chains (R = CH2CH2CH2NH3+) were replaced with methoxy groups (R = Me). Overlays represent conformers identified within the lowest 5.00 kJ/mol from 1000 Monte-Carlo conformational search steps.