Search

In the title compound, 2C14H19N4O3+·C7H3NO42−·5H2O, the asymmetric unit contains two trimethoprim cations ( A and B), a dipicolinate anion and five water mol­ecules. One of the picolinate carboxyl­ate groups inter­acts with cation A via a pair of N—H⋯O hydrogen bonds, forming a ring motif (8). A loop of O—H⋯O hydrogen bonds is formed between four water mol­ecules and the two carboxyl­ate groups to form a supramolecular chain along the a axis. Mol­ecules A and B constitute a base pair via N—H⋯N hydrogen bonds, and these base pairs are cross-linked by N—H⋯O and C—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title structure, C6H10N3+·C6H2N3O7-, the asymmetric unit consists of a 2-amino-4,6-dimethylpyrimidinium cation and a picrate (2,4,6-trinitrophenolate) anion. In the crystal structure, inversion-symmetry-related cations are paired via N—H…N hydrogen bonds, whereas inversion-related anions are paired via weak C—H…O hydrogen bonds. The cations and anions further interact with each other through N—H…O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the crystal structures of the title compounds, C6H10N3O2+·C7H5O3−·H2O, (I), C6H10N3O2+·C7H4NO4−·H2O, (II), and C6H10N3O2+·C4H5O6−·C6H9N3O2, (III), the 2-amino-4,6-di­meth­oxy­pyrimidinium cation [abbreviated as (MeO)2-Hampy+] inter­acts with the carboxyl­ate group of the corresponding anion through a pair of nearly parallel N—H⋯O hydrogen bonds to form R22(8) ring motifs. In (I), the (MeO)2-Hampy+ cation is centrosymmetrically paired through a pair of N—H⋯N hydrogen bonds involving the 2-amino group and a ring N atom forming an R22(8) motif. In (II), inversion-related R22(8) motifs (amino–pyrimidine–carboxyl­ate motifs) are further bridged by N—H⋯O hydrogen bonds on either side forming a DDAA array of quadruple hydrogen bonds. This array is extended further on either side by Owater—H⋯Ometh­oxy hydrogen bonds, resulting in an array of six hydrogen bonds ( ADDAAD). The water mol­ecule plays a pivotal role, and five hydrogen-bonded fused rings are formed around the water mol­ecule. In (III), the carb­oxy group of the tartrate anion inter­acts with the ring N atom and 2-amino group of the neutral (MeO)2-ampy mol­ecule through N—H⋯O and O—H⋯N hydrogen bonds. There is also an intra­molecular O—H⋯O hydrogen bond in the tartrate anion. In all three crystal structures, C—H⋯O hydrogen bonds are observed. [ABSTRACT FROM AUTHOR]