MII (M = Mn, Fe, Co, Ni and Cu) complexes with a chromone-derived neutral ligand: synthesis, structural characterization, photocatalytic and mycobacterial activity studies

The reaction of 2-(2-furyl)-3-hydroxychromone and nicotinoyl chloride produces a neutral ligand (L), which has nitrogen and oxygen donor atoms. Evidence of L polymorphism is discussed. The new molecule showed fluorescence emission in solution and in the solid state (intense emission at 556 nm [lambda(exc) 392 nm] in the solid state). Ligand L and coordination compounds [MCl2(L)(2)](n) (M = Mn (1), Fe (2), Co (3), Ni (4) and Cu (5)) and [Cu(NCS)(2)(L)(2)](n) (6) were characterized using spectroscopic techniques. The crystal structures were determined via single-crystal X-ray diffraction and powder X-ray diffraction. Biological tests with mycobacterial strains were conducted for compounds 1-5. The optical band gap energies of these compounds, which ranged from 3.29 to 3.39 eV, were estimated from diffuse reflectance spectroscopy data. Mesoporous TiO2-based photocatalysts were prepared and tested for hydrogen production. The m-TiO2-5 photocatalyst produced hydrogen at a 1052.5 mu mol g(-1) h(-1) rate under irradiation using a 300 W Hg/Xe lamp.

Automated summary

The study reports the reaction between 2-(2-furyl)-3-hydroxychromone and nicotinoyl chloride producing a new neutral ligand (L) and its application in coordination compounds. The researchers analyzed the polymorphism, fluorescence properties of the ligand, and the characteristics of its coordination with metal ions. Additionally, photocatalysts preparation and biological tests with mycobacterial strains were conducted.