Hydrogen-bonded supra­molecular motifs in pyrimethaminium 4-methyl­benzoate, pyrimethaminium 3-hydroxy­picolinate and pyri­meth­aminium 2,4-di­chloro­benzoate

摘要

In 2,4-diamino-5-(4-chloro­phenyl)-6-ethyl­pyrimidin-1-ium (pyri­methaminium, PMNH) 4-methyl­benzoate, C12H14ClN4 +·C8H7O2 −, (I), pyrimethaminium 3-hydroxy­picolinate, C12H14ClN4 +·C6H4NO3 −, (II), and pyrimethaminium 2,4-dichloro­benzoate, C12H14ClN4 +·C7H3Cl2O2 −, (III), the PMNH cations inter­act with the carboxyl­ate groups of the corresponding anion via nearly parallel N—H⋯O hydrogen bonds, forming R 2 2(8) ring motifs. A description of the observed arrays of quadruple hydrogen bonds in (I) and (II) in terms of hydrogen donors and acceptors (the DA model), their graph-set motifs and the resulting supra­molecular ladder is given. In (III), supra­molecular chains along the b axis and helical chains along the a axis are formed via N—H⋯O hydrogen bonds involving the 2-amino and 4-amino groups of the PMNH cation, respectively. Weak Cl⋯Cl inter­actions are also found in (III).