Polymethylene spacer linked bis(A1a) peptides form modified β:-sheet structures

The adipoyl- and suberoyl-linked bis(Ala) peptides have an extended backbone between the two C^alpha; atoms in each molecule. They self-assemble, through intermolecular hydrogen bonds and stacking of parallel strands, into highly ordered modified β-sheet-like structures. Crystal data for adipoyl bis(A1a)diester are as follows: C₁₄H₂₄N₂)O₆, monoclinic space group P2₁, a = 4.900(1), b = 29.093(10), c = 6.021(2) Å, β= 104.20(2)?, R = 0.053 for 1100 data >3σ(F); for suberoyl bis(A1a)diester: C₁₆H₂₈N₂O₆, monoclinic space group P2¹, a = 4.887(2), b = 32.650(9), c = 6.004(2) Å; β= 103.79(3), R = 0.070 for 1065 data > 3σ.