Anion-directed organized assemblies of protonated pyrazole-based ionic salts

Abstract

The reactions of 3(5)-(4-methoxyphenyl)-5(3)-phenyl-1H-pyrazole (L 1 ) with nitric acid and 5-(4-benzyloxyphenyl)-3-(furan-2-yl)-1H-pyrazole(L 2 ) with hydrochloric acid produced [HL 1 · NO3] (Salt-1) and [HL 2 · Cl] (Salt-2). The structures of Salt-1 and Salt-2 were determined by single crystal X-diffraction. In Salt-1, HL 1 showed [2 + 2] binding of NO3 − ions in the solid state to form dimer architecture with R 1 2 (4) and R 4 4 (14) graph sets. An anion directed one-dimensional anion-assisted helical chain with active participation of the chloride ion and protonated pyrazole via N–H···Cl hydrogen bonding in Salt-2. In addition, the protonated HL 2 molecules interacted with each other through weak C–H···π interactions resulting in the formation of another one-dimensional helical chain.