Crystal structures of two hydrogen-bonded compounds of chloranilic acid–ethyleneurea (1/1) and chloranilic acid–hydantoin (1/2)

Abstract

The structures of the hydrogen-bonded 1:1 co-crystal of chloranilic acid with ethyl­eneurea and the 1:2 co-crystal of chloranilic acid with hydantoin have been determined at 180 K. In the crystals of both compounds, the base mol­ecules are in the lactam form and no acid–base inter­action involving H-atom transfer is observed. The acid and base mol­ecules are linked by short O—H⋯O and N—H⋯O hydrogen bonds.