Phosphatase activity and DNA binding studies of dinuclear phenoxo-bridged zinc(II) complexes with an N,N,O-donor ligand and halide ions in a rare cis-configuration

Synthesis and characterization of phenoxo-bridged dinuclear zinc(II) halide complexes: Role of electron withdrawing group on phosphatase activity

“…The ligand was further characterized by 13 C NMR and 13 C (DEPT) NMR spectra in CDCl 3 which showed the presence of aromatic carbon signals at δ 165.48-116.78 in addition to -CH 2and -CH 3 signals at δ 57.50-45.27 ( Figures S5 and S6 in Supplementary Information). The 1 H NMR of metal complexes (1-3) were taken in D 2 O have similar type of spectra as HL2 with slightly shifted chemical shift values 30 ( Figures S7-S9 in Supplementary Information). In DMF solution, the ligand (HL2) exhibits an intra-ligand charge transfer band at 326 nm 37 along with another band at 407 nm probably due to the presence of nitro-phenolic group.…”

“…Each Zn(II) center deviates (0.635 Å for Zn1 and 0.667 Å for Zn2) considerably from the mean basal plane towards terminal chloride. Interestingly, 1 adopts an overall cis-orientation 30,40,41 where terminal chlorides are on the same side of the Zn-Zn axis. The cis-oriented Zn-Cl distances along with Zn-N(amine) lengths (Table 2) (Table 3) involving -NH-, CH 2 -and NO 2 -groups of HL2 and Cl atom along three different axes (Figure 2) to form a 3D network.…”

“…The effect of electron withdrawing −NO 2 group on HL2 is clearly noticed as k cat values lowered compared to other reported complexes. 30…”

“…15,16 Hydrolysis of phosphate esters catalyzed by metal ion is widely studied because it is involved in many biological functions like energy transduction, biosynthesis, regulation of protein and control of secondary messengers. 17,18 Various dinuclear zinc(II) complexes [19][20][21][22][23][24][25][26][27][28][29][30] have been synthesized and studied as phosphate ester models. We are actively engaged in synthesizing dinuclear zinc(II) compounds with N,N,O-donor ligands and study of their phosphatase activity.…”

“…We are actively engaged in synthesizing dinuclear zinc(II) compounds with N,N,O-donor ligands and study of their phosphatase activity. 30 In this endeavor, we have successfully synthesized and characterized three new dinuclear zinc(II) halide complexes containing a tridentate reduced Schiff base, 2-(((2-(dimethylamino)ethyl)amino)methyl)-4nitrophenol (HL2, Scheme 1) and studied their phosphatase activity. A comparative study of these results is made with our previously (Scheme 1) reported work 30 as well as with other similarly reported systems.…”