Investigation of NH-π (Ph) interaction in the 1:1[α:α-N-amino]mers using 1H NMR and FTIR absorption spectroscopy

1H NMR and FTIR experiments performed on the 1:1[α:α-N-amino]mers series let us to point out a rare NH-π interaction between the carbamidic NH of the i residue and the phenyl group of a phenylalanine residue located at i+2.