Knowledge Bank

We have obtained vibrational circular dichroism spectra (VCD) for series of films of BOC - $(L-X)n$ - OMe homo-olig o-peprides where X = Ala, Val, leu. Nva and $n=3-7$ in the Amidel and A regions. These compounds are known to form a -structure from in and CD studies. Our measurements indicate a series of changes with increasing chain length that may result from the formation of hydrogen bonds correlating to the onset of $\beta$-type bonding and then the formation of an extended 8-structure. Solution VCD spectra were also measured for $(Val)7,(Ala)6$ and $(Ala)7$ as a function of temperature and solvent variation and then correlated to the film results.