SYNTHESIS, CRYSTAL STRUCTURE OF TRIS(1,10-PHENANTHROLINE)NICKEL(II) NITRATE - 3,5-DICHLORO-2-HYDROXYBENZOIC ACID SOLVATE

Abstrak

Mixed-ligand Ni(II) complexes based on heterocyclic N-donor ligands and halogenated hydroxybenzoic acids attract considerable interest due to their structural variability, intramolecular hydrogen bonding networks, and potential biological activities. A detailed investigation of their coordination modes, supramolecular architecture, and physicochemical properties is crucial for understanding structure-property relationships in crystal engineering. This work aims to synthesize a new mixed-ligand Ni(II) coordination compound containing 1,10-phenanthroline and 3,5-dichloro-2-hydroxybenzoic acid ligands, and to thoroughly investigate its structural, crystallographic, spectroscopic, and intermolecular interaction characteristics. The SC-XRD analysis confirmed the formation of a monometallic complex constituting a tris(1,10-phenanthroline)nickel(II) cation, a nitrate anion, and four uncoordinated 3,5-dichloro-2-hydroxybenzoic acid solvate molecules per asymmetric unit. IR spectroscopy verified the non-coordinated nature of the carboxylic acid groups and charge-balancing nitrate. UV-Vis spectra confirmed the characteristic electronic transitions of the Ni(II) d-d orbitals and ligand-to-metal charge transfer.