Co-crystals of manganese(II) 1,10-phenanthroline-based complexes with 4-hydroxybenzoic acid and hippuric acid: synthesis, crystal structure and antibacterial activity

Two metal–organic co-crystal complexes with Mn(II) centre, [Mn(phen) 2 Cl 2 ][4-hbaH] ( 1 ) and [Mn(phen) 2 (H 2 O)Cl] + [hip] − Cl − .H 3 O + .2H 2 O ( 2 ) where phen = 1,10-phenanthroline; 4-hbaH = 4-hydroxybenzoic acid; hip − = hippuric acid ion, were successfully synthesized by conventional reflux method and characterized using single crystal X-ray diffraction, spectroscopic, magnetic susceptibility, thermal and EDAX analysis data. SC-XRD analysis for 1 and 2 revealed the presence of distorted octahedral Mn(II) centre complex unit where the formation of metal–organic co-crystal complexes were confirmed from the dominant supramolecular non-covalent interactions such as halogen-bonding in 1 and hydrogen-bonding in 2 . We explored the use of potential auxiliary ligands which embroidered through non-covalent interactions between organic and metal-organic moieties resulting in the formation of co-crystal with Mn(II) based supramolecular motif such as 4-hbaH in 1 and hip in 2 . The complexes were screened for their activities and showed significant antibacterial properties against bacteria pathogens. • Two novel manganese(II)-1,10-phenanthroline based co-crystal complexes with auxiliary ligands viz 4-Hydroxybenzoic acid ( 1 ) and Hippuric acid ( 2 ) were successfully synthesized. • The involvement of non-covalent interaction through halogen ( 1 ) and hydrogen ( 2 ) bonding results in supramolecular architect expansion in the final structure. • These novel compounds have been characterized using SC-XRD analysis. • Anti-bacterial activities of the compounds show significant results against Gram +ve test pathogen, Bacillus subtilis and Gram −ve, Escherichia coli.