Supramolecular interaction of a spirooxazine with amino acids

In this work, a study of the supramolecular interaction between a photochromic spirooxazine, 1,3-dihydro-1,3,3-trimethyl-8′-nitro-spiro[2H-indole-2,3′-[3H]naphth[2,1-b][1,4]oxazine] and some amino acids has been carried out. The photochrome interplays with amino acids after UV irradiation, through its zwitterionic photomerocyanine form. The interaction has a negative catalytic effect on the thermal ring closure reaction of the photomerocyanine. The strength of this interaction is a function of the size of the group (R) anchored to the α carbon atom of the amino acid and is the greater the smaller R is. This behaviour can be applied to molecular recognition.