Tautomeric properties, conformations and structure of N-(2-hydroxyphenyl)-4-amino-3-penten-2-on

Abstract

N-(2-hydroxyphenyl)-4-amino-3-penten-2-on (C11H13NO2) has been studied by X-ray analysis. It crystallizes the orthorhombic space group P212121 with a=8.834(1), b=10.508(2), c=11.212(2)Å, V=1040.8(3)Å3, Z=4, Dc=1.22gcm−3 and μ(MoKα)=0.084mm−1. The structure was solved by direct methods and refined to R=0.038 for 1373 reflections (I>2σ(I)). The title compound is photochromic and the molecule is not planar. Intramolecular hydrogen bonds occur between the pairs of atoms N(1) and O(1) [2.631(2)Å], and N(1) and O(2) [2.641(2)Å], the H atom essentially being bonded to the N atom. There is also a strong intermolecular O–H⋯O hydrogen bonding [2.647(2)Å] between neighbouring molecules. Tautomeric properties and conformations of the title compound were investigated by semi-empirical quantum mechanical AM1 calculations and the results are compared with the X-ray results.