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 ( L 1 ) and 2‐phenyl‐1, 2, 3‐triazole ( L 2 ) and their Ni II and Zn II complexes: Ni( L 1 )(hfac) 2 ( 1 ), Ni( L 2 )(hfac) 2 ( 2 ), and Zn( L 2 )(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 L 1 and L 2 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.