Synthesis and spectroscopic characterization of zinc(II) and copper(II) complexes of N,N-bis(2-picolyl)glycine as structural phosphotriestrase models: The catalyzed detoxification of paraoxon

Ibrahim, Mohamed M.

doi:10.1016/j.molstruc.2011.01.050

Cited by 13 publications

(4 citation statements)

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“…Similarly, the L2″ complex of Co contains the weaker peak at 1600 cm –1 in place of the peak between 1606 and 1607 cm –1 observed in the dpa-bound Co complexes. These findings are consistent with other reported asymmetric CC stretches for dpa and bpy complexes. − Additionally, the L2″ complexes display three medium or strong peaks in the 1450–1500 cm –1 region as opposed to the two generally observed in the dpa-bound complexes.…”

Section: Resultssupporting

confidence: 92%

“…The region between 1440 and 1620 cm –1 maintained a consistent profile for the final products resulting from reactions with each of these three reagents. This region of the IR spectra, associated with vibrations involving the pyridine rings, − was therefore identified as a marker for determining whether or not binding occurred at the dpa site (Figure ). Specifically, each spectrum contained a major peak between 1606 and 1613 cm –1 , a much smaller peak between 1571 and 1576 cm –1 , and two broad peaks of approximately equal or lesser intensity than the first between 1478 and 1487 cm –1 and between 1444 and 1451 cm –1 .…”

Section: Resultsmentioning

confidence: 99%

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Heterobimetallic Complexes of Polypyridyl Ligands Containing Paramagnetic Centers: Synthesis and Characterization by IR and EPR

et al. 2013

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Ligands containing linked dipicolylamine (dpa) and bipyridine sites have been explored as platforms for the synthesis of heterometallic complexes containing the paramagnetic metals Cu(2+) and Co(2+). IR and EPR studies on the bimetallic complexes and simplified model compounds support dpa-selective binding by both of these metals. The IR spectra have also been compared to those of diamagnetic Rh(+), Zn(2+), and Pd(2+) complexes whose metal binding sites had been independently determined through NMR techniques. The binding preferences have been used to control selective metalation in the synthesis of heterometallic Pt/Cu, Pd/Cu, and Rh/Cu complexes.

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Section: Resultssupporting

confidence: 92%

Section: Resultsmentioning

confidence: 99%

Heterobimetallic Complexes of Polypyridyl Ligands Containing Paramagnetic Centers: Synthesis and Characterization by IR and EPR

et al. 2013

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“…The development of zinc(II) complexes as biomimetic systems for metallophosphatase enzymes as well as potential catalysts for the detoxification of organophosphate (OPs) esters is of a fundamental interest since these compounds appear from day-to-day applications such as pesticides [1][2][3][4]. The harmful effects of OPs are related to their inhibition of mammalian acetylcholinesterase, an enzyme responsible for regulating the in vivo concentration of the neuro-transmitter acetylcholine [5].…”

Section: Introductionmentioning

confidence: 99%

“…These ligands were designed to coordinate to the zinc(II) ion while leaving zinc(II) coordinatively unsaturated, enabling the coordination of a water molecule. The aqua zinc complexes [(L)Zn(OH 2 )] 2+ formed can then generate [(L)Zn(OH)] + species at the catalytic site during the hydrolytic action of zinc enzyme model complexes [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Hydrolysis and Detection of Organophosphate by Benzimidazole Containing Ligand-Based Zinc(II) Complexes

et al. 2021

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The agricultural use of organophosphorus pesticides is a widespread practice with significant advantages in crop health and product yield. An undesirable consequence is the contamination of soil and groundwater by these neurotoxins resulting from over application and run-off. Here, we design and synthesize the mononuclear zinc(II) complexes, namely, [Zn(AMB)2Cl](ClO4) 1 and [Zn(AMB)2(OH)](ClO4) 2 (AMB = 2-aminomethylbenzimidazole), as artificial catalysts inspired by phosphotriesterase (PTE) for the hydrolysis of organophosphorus compounds (OPs) and simultaneously detect the organophosphate pesticides such as fenitrothion and parathion. Spectral and DFT (B3LYP/Lanl2DZ) calculations revealed that complexes 1 and 2 have a square-pyramidal environment around zinc(II) centers with coordination chromophores of ZnN4Cl and ZnN4O, respectively. Both 1 and 2 were used as a modifier in the construction of a biomimetic sensor for the determination of toxic OPs, fenitrothion and parathion, in phosphate buffer by square wave voltammetry. The hydrolysis of OPs using 1 or 2 generates p-nitrophenol, which is subsequently oxidized at the surface of the modified carbon past electrode. The catalytic activity of 2 was higher than 1, which is attributed to the higher electronegativity of the former. The oxidation peak potentials of p-nitrophenol were obtained at +0.97 V (vs. Ag/AgCl) using cyclic voltammetry (CV) and +0.88 V (vs. Ag/AgCl) using square wave voltammetry. Several parameters were investigated to evaluate the performance of the biomimetic sensor obtained after the incorporation of zinc(II) complex 1 and 2 on a carbon paste electrode (CPE). The calibration curve showed a linear response ranging between 1.0 μM (0.29 ppm) and 5.5 μM (1.6 ppm) for fenitrothion and 1.0 μM (0.28 ppm) and 0.1 μM (0.028 ppm) for parathion with a limit of detection (LOD) of 0.08 μM (0.022 ppm) and 0.51 μM (0.149 ppm) for fenitrothion and parathion, respectively. The obtained results clearly demonstrated that the CPE modified by 1 and 2 has a remarkable electrocatalytic activity towards the hydrolysis of OPs under optimal conditions.

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The Crystal Structure and Cytotoxicity of Centrosymmetric Copper(II) Complex Derived from S-methyldithiocarbazate with Isatin

et al. 2011

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Copper(II) complex of S-methyldithiocarbazate with isatin has been prepared and screened for their cytotoxic activities against MCF-7 (Human non-metastatic mammary gland adenocarcinoma cell line) and MDA-MB-231 (Human metastatic mammary gland adenocarcinoma cell line). The compound crystallized in an orthorhombic crystal system with a space group C 2cb and was found to be selectively active against MCF-7 cell line (Human non-metastatic mammary gland adenocarcinoma cell line with an IC50 value 0.45 μg/mL. The crystal structure of this centrosymmetric Cu(SMISA)2 complex (SMISA = Schiff base formed by condensation reaction of S-methyldithiocarbazate with isatin) showed that the copper atom has a distorted square-planar geometry with the Schiff base coordinated to the metal ion as a uninegatively charged bidentate ligand through the azomethine nitrogen and thiolate sulfur.

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Synthesis and spectroscopic characterization of zinc(II) and copper(II) complexes of N,N-bis(2-picolyl)glycine as structural phosphotriestrase models: The catalyzed detoxification of paraoxon

Cited by 13 publications

References 54 publications

Heterobimetallic Complexes of Polypyridyl Ligands Containing Paramagnetic Centers: Synthesis and Characterization by IR and EPR

Heterobimetallic Complexes of Polypyridyl Ligands Containing Paramagnetic Centers: Synthesis and Characterization by IR and EPR

Simultaneous Hydrolysis and Detection of Organophosphate by Benzimidazole Containing Ligand-Based Zinc(II) Complexes

The Crystal Structure and Cytotoxicity of Centrosymmetric Copper(II) Complex Derived from S-methyldithiocarbazate with Isatin

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