Nickel(II) Complexes with a Hydroxyl Pendant‐Armed Macrocyclic Ligand: Synthesis, Characterization, and Crystal Structures

Abstract

AbstractThe reactions of different nickel(II) salts with a mixed‐donor macrocyclic ligand L (6,7,8,9,10,11,18,19‐octahydro‐5H, 17H‐dibenzo[f,o][1,5,9,13] dioxadiazacyclohexadecin‐18‐ol), potentially pentadentate N2O3 donor sets containing one pendant alcohol function have been investigated. The physical properties and the chemical structures of 1:1 (metal:ligand) NiLX2 (X = Cl−, Br−, NO3−, ClO4−) complexes have been characterized by using IR, UV‐Vis spectroscopy and conductance measurements. The X‐ray determination have been employed to probe the nature of the respective complexes in solid state. The nickel atom in [NiL(NO3)]NO3·0.5H2O complex is six‐coordinate with a distorted octahedral coordination in which the all N2O3 donor atoms are coordinated to the nickel atom. The coordination sphere is completed by a nitrate anion. In contrast to the above nickel complex, in [NiLCl2] complex the pendant hydroxyl arm of macrocycle remains uncoordinated and ligand acts as tetradentate N2O2 donor atoms. The coordination sphere is completed by two chloride anions and the nickel atom is six‐coordinate with a distorted octahedral coordination.