Three Nickel(II) and Zinc(II) Complexes with Two Novel Nitronyl Nitroxide Ligands: Syntheses,Crystal Structures,and Luminescent Properties

To explore the coordination abilities of nitronyl nitroxide ligands, two ligands substituted with quinoxaline ( L¹ ) and 2‐phenyl‐1, 2, 3‐triazole ( L² ) and their Ni^II and Zn^II complexes: Ni( L¹ )(hfac)₂ ( 1 ), Ni( L² )(hfac)₂ ( 2 ), and Zn( L² )(hfac)₂ ( 3 ) (hfac = hexafluoroacetylacetonate), were synthesized and characterized. X‐ray single‐crystal diffraction analysis shows that compound 1 has a mononuclear structure, which is further linked into a three‐dimensional (3D) supramolecular network by C–H ··· F hydrogen‐bonding, C–H ··· π, and π ··· π stacking interactions. Complexes 2 and 3 have similar mononuclear structures, which are further linked into one‐dimensional (1D) supramolecular chains by various intermolecular weak interactions, such as C–H ··· F hydrogen‐bonding, and π ··· π stacking interactions. The results indicate that the steric bulk of L¹ and L² and the existence of hexafluoroacetylacetonate (hfac) play important roles in controlling the formation of the final frameworks of complexes 1 – 3 . Moreover, the luminescent properties of the ligands and their complexes were investigated in detail.