Mixed ligand coordination complex of Mn(II) containing oxidized pyridine-2,6- dicarboxylic acid and 1,10-phenanthroline: Synthesis and characterization

For the last two decades, the synthesis of mixed ligand coordination compounds with transition metals and their applications have become an attractive field because ofthe excellent properties such as catalysis, ion exchange, microelectronics, nonlinear optics, porous materials, etc. The use of acid–base mixed ligands is a very suitable method for the preparation of these compounds. Naturally, acid and base ligands are perfect partners that can compensate charge balance, coordination deficiency,repulsive vacuum, and weakly interaction all at once.1 For this purpose, polycarboxylic acids and N-heterocycle bases are very excellent candidates.2 As an aromatic polycarboxylate ligand derived from pyridinedicarboxylic acid, pyridine-2,6- dicarboxylic acid N-oxide (H2pydco), has limited steric hindrance and weak stacking interactions and can form various coordination structures through carboxylate and Noxide bridges.3 In this work, H2pydco as a primary ligand and 1,10-phenanthroline (phen) as secondary ligands were employed to synthesis mixed ligand coordination complex of Mn(II). This compound has been characterized by melting point, elemental analysis, infrared spectroscopy (IR), and thermogravimetric (TGA) analysis. The purpose molecular formula [Mn(pydco)(phen)(H2O)] (1) is confirmed by results (Fig. 1).