The cis-structure, VI, forces the tetradentate ligand to coordinate in a nonplanar fashion .
The reduction of Racah parameter from the free ion value of 971 [cm.sup.-1] to 744 [cm.sup.-1] and the [[beta].sup.0] value (23%) indicates the covalent nature of the compound and the strong field nature of the tetradentate ligand .
Regarding the NTA, coordination occurs between three carboxyl groups and the nitrogen and thus a tetradentate ligand
. In this case, as the objective was to investigate complexes with octahedral geometry, since they tend to be more stable, for development of the structures two water molecules were used as ligand, thus completing the valence six of the chromium.
All the transition metal complexes show same structure whereby the metal ion is surrounded by a single tetradentate ligand
producing square planar geometry.
Schiff bases are mostly mono-, bi-, tri-, and tetradentate ligands
, which can coordinate with various metals and form very stable metal complexes.
These ligands are quite familiar as tetradentate ligands
in metal complexes [4-6].
Nazeeruddin et al., "Novel ruthenium sensitizers containing functionalized hybrid tetradentate ligands
: synthesis, characterization, and INDO/S analysis," Inorganic Chemistry, vol.
Ghammamy, Synthesis, Characterization and Anti-Tumor Activity of Iron (III) Schiff Base Complexes with Unsymmetric Tetradentate Ligands
Delaume, Synthesis, Characterization and Electrochemical Behaviour of Some Copper(II) Complexes with Linear and Tripodal Tetradentate Ligands
Derived From Schiff Bases, Polyhedron, 16, 2175 (1997).