Synthesis,magnetic properties, and catalytic properties of a nickel(II)-dependent biomimetic of metallohydrolases

• Verfasst von: Horn, Adolfo <Jr.> [VerfasserIn]
• Verfasst von: Englert, Daniel [VerfasserIn]
• Verfasst von: Roberts, Asha E. [VerfasserIn]
• Verfasst von: Comba, Peter [VerfasserIn]
• Titel: Synthesis,magnetic properties, and catalytic properties of a nickel(II)-dependent biomimetic of metallohydrolases
• Verf.angabe: Adolfo Horn Jr., Daniel Englert, Asha E. Roberts, Peter Comba, Gerhard Schenk, Elizabeth H. Krenske, Lawrence R. Gahan
• E-Jahr: 2018
• Jahr: 25 September 2018
• Umfang: 14 S.
• Fussnoten: Gesehen am 13.06.2019
• Titel Quelle: Enthalten in: Frontiers in Chemistry
• Ort Quelle: Lausanne : Frontiers Media, 2013
• Jahr Quelle: 2018
• Band/Heft Quelle: 6(2018) Artikel-Nummer 441, 14 Seiten
• ISSN Quelle: 2296-2646
• DOI: doi:10.3389/fchem.2018.00441
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: : Nickel
• Sach-SW: DFT
• Sach-SW: Kinetics
• Sach-SW: magnetism
• Sach-SW: Mechanism
• Sach-SW: Phosphoesterase
• K10plus-PPN: 1667350641

Abstract

A dinickel(II) complex of the ligand 1,3-bis(bis(pyridin-2-ylmethyl)amino)propan-2-ol (HL1) has been prepared and characterized to generate a functional model for nickel(II) phosphoesterase enzymes. The complex, [Ni2(L1)(OAc)(H2O)2](ClO4)2·H2O, was characterized by microanalysis, X-ray crystallography, UV-visible and IR absorption spectroscopy and solid state magnetic susceptibility measurements. Susceptibility studies show that the complex is antiferromagnetically coupled with the best fit parameters J = -27.4 cm-1, g = 2.29, D = 28.4 cm-1, comparable to corresponding values measured for the analogous dicobalt(II) complex [Co2(L1)(OAc)](ClO4)2·0.5 H2O ( J = -14.9 cm-1 and g = 2.16). Catalytic measurements with the diNi(II) complex using the substrate bis(2,4-dinitrophenyl)phosphate (BDNPP) demonstrated activity toward hydrolysis of the phosphoester substrate with Km =11 ± 2 mM, and kcat = 2.5 ± 0.05 x 10-5 s-1. The combination of structural and catalytic studies suggests that the likely mechanism involves a nucleophilic attack on the substrate by a terminal nucleophilic hydroxido moiety.