Content with our ability to tune peptide conformation using reagents Pinc and 2, we finally turned our attention towards the structures of 4-amino benzoic acid derived peptides 14a and 16a (Figure ). Unlike other peptides examined in this study, substituents on the aryl ring had little structural impact on the peptide conformation. Both 14a and 16b possessed near identical turn motifs and secondary structures. Perhaps more intriguingly, both peptides lacked the IMHB between the NH of Gly2 and the endocyclic amine of Pro1. As far as we can tell, this is the only example in which this rigid hydrogen bond has been disrupted through contortion of the peptide backbone. Disruption of this reduced amide IMHB was verified through our variable temperature NMR experiments. Typically, in the other peptides in this study, the temperature coefficient of the NH of Gly2 was determined to be <1 ppb/K. Remarkably, in peptides 14a and 16a, this same temperature coefficient was determined to be 6 ppb/K.