327065-06-5Relevant academic research and scientific papers
Remarkable reactivity of alkoxide/acetato-bridged binuclear copper(II) complex as artificial carboxylesterase
Xu, Bin,Jiang, Weidong,Liu, Xiaoqiang,Liu, Fuan,Xiang, Zheng
, p. 625 - 635 (2017)
Abstract: Bromo-containing binuclear Schiff base copper(II) complex, Cu2L(OAc), with an alkoxo/acetato-bridged moiety was employed as a model of carboxylesterases to promote the hydrolytic cleavage of p-nitrophenyl picolinate (PNPP). Furthermore, the reactivity of a mononuclear complex (CuHL) was evaluated for comparing it with that of binuclear one. The results reveal that the as-prepared binuclear Cu2L(OAc) efficiently accelerated the hydrolysis of PNPP, giving rise to excess four orders of magnitude rate enhancement in contrast to the un-catalyzed reaction. Cu2L(OAc) represented an enzyme-like bell-shaped pH-responsive kinetic behavior. Moreover, the binuclear one is more reactive than its mononuclear analogue (CuHL) by two orders of magnitude. The total efficiency of Cu2L(OAc) is about 61-fold than that of its mononuclear analogue, CuHL. In addition, a contrast experiment reveals that binuclear Cu2L(OAc) displayed good activity in the hydrolysis of PNPP as well another active ester, i.e., S-2-benzothiazolyl 2-amino-alpha-(methoxyimino)-4-thiazolethiolacetate (AE-active ester). Noteworthyly, it was found that mononuclear one inspired more obvious rate enhancement in the hydrolysis of AE-active ester relative to PNPP hydrolysis. The estimated pKa1 of bound water on the binuclear Cu2L(OAc) using second derivative method (SDM) is relatively smaller than that for CuHL by a gap of about 0.8 pK unit, which facilitates the hydrolysis of PNPP. Graphical Abstract: Four orders of magnitude rate enhancement was observed for the catalytic hydrolysis of p-nitrophenyl picolinate (PNPP) by one μ-alkoxide/acetato-bridged binuclear copper(II) complex under physiological conditions. Substrate specificity of the resulting binuclear complexes was observed for the hydrolysis of PNPP and AE-active ester.
Crystal structure and magnetic properties of a binuclear copper(II) complex bridged by an alkoxo-oxygen atom and an acetate ion
Zeyrek,Elmali,Elerman,Svoboda,Fuess
, p. 1067 - 1073 (2000)
[Cu4(L)2(O2CMe)2]·H 2O (L = 1,3-bis(5-bromo-2-hydroxybenzylidene)propan-2-ol) was synthesized and its crystal structure determined. (C38H34N4O10Br4Cu 4)·H2O, monoclinic, space group P21/c, a = 21.072(5), b = 9.673(2), c = 21.934(4) A?, β = 109.73(2)°, V = 4208(2) A?3, Z = 4. The crystal structure consists of two independent binuclear copper(II) complexes and the non-coordinating water molecule in the asymetric unit. The Cu(II) ions are in a square-planar geometry and coordinated by donor atoms of the ligand (NO3). The average Cu?Cu distance and average Cu-O-Cu angle are 3.491(2) A? and 132.0(1)°, respectively. Temperature-dependent magnetic susceptibility measurements of the complex show an intramolecular antiferromagnetic coupling in the dimeric Cu(II) core. The fitting parameters are -2J = 174.4 cm-1, g = 1.98.
Magnetic properties and crystal structure of a 3,5-dimethylpyrazolate-bridged binuclear copper(II) complex
Elerman,Elmali
, p. 970 - 974 (2001)
[Cu2L(prz)] (prz = 3,5-dimethylpyrazole and L = 1,3-bis(5-bromo-2-hydroxybenzylidene)-propan-2-ol) was synthesized and its crystal structure determined. It crystallizes in the orthorhombic space group Pbca with a = 14.160(9), b = 15.109(4), c = 21.298(5) ?, V = 4557(1) ?3 Z = 8. Two copper(II) ions are in a square-planar coordination. The metal coordination sphere is four-coordinate, with a planar N2O2 donor set. The dihedral angle between the two coordination planes is 12.14(7)°. The copper(II) centers are separated by 3.365(1) ? and antiferromagnetically coupled (J = -214.3 cm-1), which follows from temperature-dependent magnetic susceptibility measurements in the temperature range 4.6 to 310 K. The Cu-O-Cu angle is 125.9(1)° in the super-exchange pathway. The magnetic moment at 310 K is ca. 1.76 B.M. and 0.13 B.M. at 4.6 K.
Synthesis, characterization, superoxide dismutase, and antimicrobial activities of Co (II) complexes with Schiff base ligand and their hybrid proteins
Bian, Hedong,Guan, Yifu,Jaiswal, Yogini,Mo, Dan,Shen, Yunjun,Song, Xun,Wu, Jiri,Zhang, Yuzhen
, (2022/01/19)
Metal complexes have been reported to possess excellent free radical scavenging and antimicrobial properties. In the present study, seven linear trinuclear complexes were synthesized based on bis Schiff base ligand and complexes 1, 3–7 are reported for th
