Abstract: | Abstract: Crystal structure analysis of a model peptide: Boc‐β‐Ala‐Aib‐β‐Ala‐NHCH3 (β‐Ala: 3‐amino propionic acid; Aib: α‐aminoisobutyric acid) revealed distinct conformational preferences for folded φ≈136°, µ ≈ ?62°, ψ ≈100°] and semifolded φ ≈ 83°, µ ≈ ?177°, ψ ≈ ?117°] structures of the N‐ and C‐terminus β‐Ala residues, respectively. The overall folded conformation is stabilized by unusual Ni···H‐Ni+1 and nonconventional C–H···O intramolecular hydrogen bonding interactions. |