The new helical zigzag chain {[Ag(Pepy)(NO3)]}∞ and mononuclear [HPepy(FeCl4)] with 3D network based on hydrogen bonds as well as π–π interactions

The title complexes, {[Ag(Pepy)(NO3)]}∞ (1) and [HPepy(FeCl4)] (2) (Pepy = trans-2-(2-phenylethyleneyl)pyridine), had been synthesized and characterized structurally by single-crystal X-ray diffraction analysis, FTIR as well as thermal analysis. The geometrical structure of complex 1 is a one-dimensional helical zigzag chain. Each AgI center is five-coordinated by two NO3- anions and one Pepy ligand while the NO3- anion is an uncommon tetra-dentate coordinating to two AgI by O atoms, respectively. The NO3- anions connecting with AgI as bridge blocks resulted in the formation of crystalline of helical polymeric chain. In the mononuclear complex 2, the FeIII center is four-coordinated by four Cl− as [FeCl4]− anion, which connected with hydrogen atoms from the protonated N atom and the C atoms from HPepy+ to form multivalent hydrogen bonded network through N–H⋯Cl and C–H⋯Cl interactions. The two frameworks can be both considered as a 3D structure driven by diverse hydrogen bonds as well as π–π stacking interactions.

A new helical zigzag chain complexes 1 was constructed by direct reactions of AgNO3 with monodentate ligand of trans-2-(2-phenylethyleneyl)pyridine (Pepy), the nitrate anion acts as bridge block. In the mononuclear complex 2, the FeIII center is four-coordinated with four Cl− anions, the N atom of Pepy is protonated which interacts with [FeCl4]− anion through N–H⋯Cl hydrogen bond and C–H⋯Cl interactions. The final frameworks can be considered as a 3D structure driven by diverse hydrogen bonds as well as π–π stacking interactions.Figure optionsDownload as PowerPoint slide