Supramolecular Arrays of Cationic Complexes Containing Pyrazole Ligands and Tetrafluoroborate,Trifluoromethanesulfonate, or Nitrate as Counterions. Crystal Structure of Bis(3,5‐dimethyl‐4‐nitro‐1H‐pyrazole‐κN2)silver(1+) Nitrate ([Ag(HpzNO2)2](NO3))

The structures of Pd(η³‐C₃H₅)(Hpz^R2)₂](BF₄) (Hpz^R2=Hpz^bp2=3,5‐bis(4‐butoxyphenyl)‐1H‐pyrazole, 1 ; Hpz^R2=Hpz^NO2=3,5‐dimethyl‐4‐nitro‐1H‐pyrazole=Hdmnpz, 2 ) and Ag(Hpz^R2)₂](A) (Hpz^R2=Hpz^bp2, A= , 3 ; Hpz^R2=Hpz^NO2, A= , 4 ) were comparatively analyzed to determine the factors responsible for polymeric assemblies. In all cases, the H‐bonding interactions between the pyrazole moieties and the appropriate counterion and, in particular, the orientation of the NH groups of the pyrazole ligands are determinant of one‐dimensional polymeric arrays. In this context, the new compound Ag(Hpz^NO2)₂](NO₃) ( 5 ) was synthesized and its structure analyzed by X‐ray diffraction (Fig. 4). The Hpz^NO2 serves as N‐monodentate ligand, which coordinates to the Ag^I center through its pyrazole N‐atom giving rise to an almost linear N? Ag? N geometry. The planar NO counterion bridges two adjacent Ag^I centers to form a one‐dimensional zigzag‐shaped chain which is also supported by the presence of N? H???O bonds between the pyrazole NH group of adjacent cationic entities and the remaining O‐atom of the bridging NO (Fig. 5). The chains are further extended to a two‐dimensional layer‐like structure through additional Ag???O interactions involving the NO₂ substituents at the pyrazole ligands (Fig. 6).