Cu(II) and Co(II) complexes of benzimidazole derivative: Structures, catecholase like activities and interaction studies with hydrogen peroxide

Present study describes the synthesis and single crystal X-ray structures of two metal complexes of benzimidazole derivative (PBI), viz. the Cu(II) complex, [Cu(PBI)2(NCS)]ClO4 (1) and a Co(II) complex, [Co(PBI)2(NCS)1.75Cl0.25] (2). The Cu(II) complex (1) shows catecholase like activity having Kcat = 1.84 × 104 h−1. Moreover, interactions of the complexes with hydrogen peroxide have been investigated using fluorescence spectroscopy. The interaction constant of 1 and 2 for H2O2 are 6.67 × 102 M−1 and 1.049 × 103 M−1 while their detection limits for H2O2 are 3.37 × 10−7 M and 2.46 × 10−7 M respectively.