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

Abstract

AbstractTo explore the coordination abilities of nitronyl nitroxide ligands, two ligands substituted with quinoxaline (L1) and 2‐phenyl‐1, 2, 3‐triazole (L2) and their NiII and ZnII 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.