Crystal structures and anti-oxidant capacity of ( E )-5-benz-yloxy-2-{[(4-chloro-phen-yl)imino]-meth-yl}phenol and ( E )-5-benz-yloxy-2-({[2-(1 H -indol-3-yl)eth-yl]iminium-yl}meth-yl)phenolate.

The title Schiff base compounds, C20 H16 ClNO2 (I) and C24 H22 N2 O2 (II), were synthesized via the condensation reaction of 2-amino-4-chloro-phenol for (I), and 2-(2,3-di-hydro-1 H -indol-3-yl)ethan-1-amine for (II), with 4-benz-yloxy-2-hy-droxy-benzaldehyde. In both compounds, the configuration about the C=N imine bond is E . Neither mol-ecule is planar. In (I), the central benzene ring makes dihedral angles of 49.91 (12) and 53.52 (11)° with the outer phenyl and chloro-phenyl rings, respectively. In (II), the central benzene ring makes dihedral angles of 89.59 (9) and 72.27 (7)°, respectively, with the outer phenyl ring and the mean plane of the indole ring system (r.m.s. deviation = 0.011 Å). In both compounds there is an intra-molecular hydrogen bond forming an S (6) ring motif; an O-H⋯O hydrogen bond in (I), but a charge-assisted N+ -H⋯O- hydrogen bond in (II). In the crystal of (I), mol-ecules are linked by C-H⋯π inter-actions, forming slabs parallel to plane (001). In the crystal of (II), mol-ecules are linked by pairs of N-H⋯O hydrogen bonds, forming inversion dimers. The dimers are linked by C-H⋯O hydrogen bonds, C-H⋯π inter-actions and a weak N-H⋯π inter-action, forming columns propagating along the a -axis direction. The anti-oxidant capacity of the synthesized compounds was determined by cupric reducing anti-oxidant capacity (CUPRAC) for compound (I) and by 2,2-picrylhydrazyl hydrate (DPPH) for compound (II).