A novel five-coordinated silver complex {[Ag(HPPz)4(NO3)](NO3)4} [PPz=trans-2-(2-phenylethenyl)pyrazine]: Self-assembly of supramolecular architecture based on NO3− anions

The title complex {[Ag(HPPz)4(NO3)](NO3)4}, 1, has been prepared from the reaction of trans-2-(2-phenylethenyl)pyrazine (PPz) with AgNO3 at room temperature in 10% HNO3 and structurally determined by single-crystal X-ray diffraction analysis. The result shows that the AgI center is five-coordinated with one NO3− anion and four mono-protonated HPPz+ ligands. The NO3− anions display versatility not only participating in coordination, but also linking the HPPz+ ligands by electrostatic and hydrogen bond interactions. The final framework can be considered as a 3D supramolecular architecture built up by the self-assembly of the building blocks ([Ag(HPPz)4(NO3)]3+, NO3−), driven by diverse interactions based on the NO3− anions.