Six coordinate Ni(II) complexes of ONN donor aroylhydrazone ligands: synthesis, spectral studies, and crystal structures

Abstract

A new ligand N¢-(pyridin-2-ylmethylene) nicotinohydrazide (HL 2 ) and two Ni(II) complexes of stoichiometry NiL 1 ÁH 2 O [L 1 -2-benzoylpyridine nicotinoylhydrazone] and NiL 2 ÁH 2 O have been synthesized and characterized by elemental analyses, IR and UV-Vis spectral studies. Structures of HL 2 and Ni(II) compounds have been determined by single crystal X-ray diffraction studies which reveal a distorted octahedral geometry around the two Ni(II) centers.

Versatile binding properties of a di-2-pyridyl ketone nicotinoylhydrazone ligand: Crystal structure of a Cu(II) complex

“…2. The metal chelate ring Cg(8) {N6, C18, C19, C20, C21, C22} is stacked via -interactions with Cg(9) {N9, C30, C31, C32A, C33A, C34} of the neighboring unit with a centroid to centroid distance of 3.708(5)Å [23]. In addition to the -stacking, significant C-H· · · interactions of the pyridyl hydrogens with metal chelate rings of the neighboring molecules adds the stability of the unit cell packing (Table 3).…”

Synthesis, spectral and structural studies of oxovanadium(IV/V) complexes derived from 2-hydroxyacetophenone-3-hydroxy-2-naphthoylhydrazone: polymorphs of oxovanadium(V) complex [VOL(OCH3)]

“…The richness and importance of vanadate chemistry have emerged for quite some time [5][6][7]. In continuation of our work on the synthesis and characterization of aroyl hydrazones and their coordination compounds [8][9][10][11][12], we report here the synthesis and characterization of oxovanadium (IV/V) complexes of 2-hydroxyacetophenone-3-hydroxy-2-naphthoylhydrazone (H 2 L) along with the crystal structure of an oxovanadium(V) complex existing in two polymorphic forms. In addition to the azomethine nitrogen and carbonyl oxygen, the coordinating capacity of the ligand has been enhanced by the presence of coordinating oxygen in the phenyl ring of aromatic ketone.…”

Aroylhydrazone‐based nickel(II) complexes: Synthesis and their structural, density functional theory (DFT), biological and catalytic studies

“…The slight shift in absorption bands observed in the complexes may be attributed to the donation of lone pair electrons to the metal center and the feasible binding of the hydrazone ligand through the azomethine nitrogen 28,32 . The nickel(II) complexes 1 and 2 show strong bands at 410 and 422 nm, respectively, indicating ligand‐to‐metal charge transfer transitions from the coordinated hydrazone ligand to the metal ion 32,68 . In general, the charge transfer peaks' positions are influenced by the steric properties of the substituents in the hydrazone group.…”

“…28,32 The nickel(II) complexes 1 and 2 show strong bands at 410 and 422 nm, respectively, indicating ligand-to-metal charge transfer transitions from the coordinated hydrazone ligand to the metal ion. 32,68 In general, the charge transfer peaks' positions are influenced by the steric properties of the substituents in the hydrazone group. In all of the complexes, the respective bands have broadened peaks that extend into the visible range of the spectrum.…”