New 4-(3,4-dicarboxylphenyloxy)-4-biphenyl carboxylic acid appended Ni (II) complexes as photocatalysts for dimetridazole photodegradation

Two new Ni(II) complexes having compositions [Ni(phen)(HL)(H2O)] (1) and [Ni2(phen)2(H2L)2(H2O)6 & sdot;2H2L] (2) (H3L = 4 '-(3,4-dicarboxylphenyloxy)-4-biphenyl carboxylic acid; phen = 1,10-phenanthroline), have been successfully synthesized solvothermally and characterized by microanalyses, FTIR and single crystal X-ray diffraction. The single crystal X-ray diffraction analyses revealed that both 1 and 2 possess distorted octahedral geometry and displayed varied types of non-covalent interactions to stabilize their solid state frameworks. Further, these complexes have been used as photocatalysts for the photodegradation of antibiotics. The photo catalysis experiments reveal that 1 is relatively a better photocatalyst than 2 for photo-decomposing dimetridazole (DTZ) upto 92.5 % in time spans of 45 min. Additional investigation on 1 suggests that it retains its photocatalytic activity after six catalytic cycles indicating its efficient catalytic activity and reusability. The plausible photocatalytic mechanism have been addressed with the help of density of states plots and Hirshfeld surface analyses.