No abstract

Reactions of silver(I) salts with the isomeric pyridyl amide ligands methyl-4-(pyridin-2-ylcarbamoyl)benzoate (L 1 ), methyl-4-(pyridin-3-ylcarbamoyl)benzoate (L 2 ) and methyl-4-(pyridin-4-ylcarbamoyl)benzoate (L 3 ) and the pyrimidyl amide ligand methyl-4-(pyrimidin-2-ylcarbamoyl)benzoate (L 4 ) afforded the complexes Ag 4 (L 1 ) 4 (NO 3 ) 4 9), which were structurally characterized by X-ray crystallography. The L 1 -L 3 ligands in 1-6 adopt monodentate bonding modes, which coordinate to the metal centers through the pyridyl nitrogen atoms, whereas the L 4 ligands of 7-9 adopt a bidentate mode, featuring chelation through one pyrimidyl nitrogen atom and the amide oxygen atom. All nine complexes adopt discrete structures with 1 being tetranuclear and 2-9 being mononuclear. Moreover, Ag … Ag short contacts, p … p stacking interactions and/or Ag … O interactions are found in these complexes which extend the dimensionalities of the structures. The changes of the donor atom positions and counteranions significantly affect the supramolecular structures of these complexes and the L 1 -L 4 ligands are sufficiently flexible to adopt the cis and/or trans conformations.

Mol­ecules of the title compound, C18H14N4O2, are located around an inversion center and connected into chains in the crystal via inter­molecular N—H⋯N hydrogen bonds generating an R 2 2(8) motif.

In the title molecular salt, C12H12N4O2 2+·2ClO4 −, the complete cation is generated by crystallographic inversion symmetry. In the crystal, the cations and anions are linked via N—H⋯O and N—H⋯(O,O) hydrogen bonds, forming a three-dimensional framework.