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A Tetradentate β‐Diiminato Ligand Containing Phenolate Substituents: Flexivalent Coordination to Mn III , Co III , Ni II , and Cu II
Author(s) -
Faraj Fadhil Lafta,
Khaledi Hamid,
Morimoto Yuma,
Itoh Shinobu,
Olmstead Marilyn M.,
Ali Hapipah Mohd
Publication year - 2014
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201402745
Subject(s) - chemistry , deprotonation , ligand (biochemistry) , nickel , denticity , cobalt , inorganic chemistry , divalent , coordination complex , metal , manganese , coordination sphere , chelation , crystallography , copper , octahedron , stereochemistry , medicinal chemistry , crystal structure , ion , organic chemistry , biochemistry , receptor
A functionalized β‐dialdimine was prepared, bearing a 3,3‐dimethylindoleninyl group at the meso ‐position and two N ‐phenolic groups. The structure contains three labile protons, which can be lost or migrate through tautomerism to provide an N 2 O 2 coordination core. A number of divalent and trivalent metal ions (Cu II , Ni II , Co II/III , and Mn III ) were accommodated inside the core, forming a series of intensely colored products consisting of a tricyclic MN 2 O 2 chelate. In the resulting divalent metal complexes, the dialdimine ligand is deprotonated only at the two phenolic oxygen atoms and is thus dianionic, whereas in the trivalent metal complexes, the dialdiminato ligand is triply deprotonated. The copper and nickel complexes adopt square‐planar geometries, whereas in the trivalent cobalt and manganese complexes, two neutral ancillary ligands complete an octahedral geometry around the metal center. In each case, the denticity of the diimino–diiminato ligand is four. The electrochemical oxidation of the copper and nickel complexes was studied by cyclic voltammetry.