Other characterization studies showed that substituted bipyridine acted as a tridentate ligand, with two pyridine N and one carboxylic O atom as binding sites per ligand molecule.
Keywords: Substituted bipyridine, Stoichiometry, Bipyridine complexes, Tridentate ligand, Electrochromism, Cyclic voltammetry
The synthesized ligand, anticipated as a tridentate ligand, was complexed with Fe (II) and Co (II) to study subsequent effects of polydendate ligand on their electrochromic properties.
IR studies strongly suggest that the ligand reacts with metal ions as a tridentate ligand which also favors the proposed structure for synthesized complexes.
3-(2-(2-hydroxy-3-methoxybenzylidene)hydrazono)indolin-2-one, acted as a tridentate ligand
and coordinated through phenolic oxygen, azomethine nitrogen and carbonyl group.
This can be achieved by using a dibasic tridentate ligand around octahedral molybdenum(VI) [9-13].
The analytical data (Table 1) show that the Schiff bases behave as dibasic, tridentate ligands, hence complete replacement of the bidentate acetylacetone occurs under the reaction conditions and the ethanol occupies the sixth coordination position.
As is evident from the above data, the Schiff base ligands(1a-3a) behave as dibasic tridentate ligands and co-ordinate through phenolic oxygen, azomethine nitrogen and enolic oxygen atoms.
Tyrosine is a potentially tridentate ligand
but it coordinates only through the carboxylato oxygen.
Depending on the pH and metal atom, amino acids can act as monodentate, bidentate and tridentate ligands and they can be either bridging or non- bridging ligands [17-19].
Structural Characterization and Solution Behavior of Complexes with Thioether-Bearing Amino Acids as Tridentate Ligands Inorg.
In summary (BROM-ANIS), (BROM-DMB) and (BROM-MB) behave as bidentate ligands via N-imine donor atom and amine nitrogen atom (attached with cyclohexyl ring of ligand) in complexes (1a)-(1c), (2a)-(2c) and (3a)-(3c) but (BROM-HB) and (BROM-o-VANI) behave as tridentate ligands
via phenolic-O, imine-N and amine-N donor atoms in complexes (4a)-(4c) and (5a)-(5c).