• Journal of Applied Biological Chemistry
• /
• 제49권3호
• /
• pp.86-89
• /
• 2006

The novel tetranuclear nickel (II) complex is a high rate accelerator in promoting hydrolysis of phosphate diesters. Nickel-bound bis-nitrophenyl phosphate (BNPP) can be $10^4$ times more reactive than the unbound BNPP. The large rate of enhancements by the complex slightly under basic condition has shown high catalytic activity in phosphate diester cleavage. The bell-shaped pH-rate profile indicated that the nickel-oxide form of the tetranuclear complex or its kinetic equivalent was the active species for cleaving BNPP. The catalytic hydrolysis between tetranuclear nickel (II) complex and phosphate diester proceeds via the formation of bidentate coordination of the anionic phosphate to the Ni (II) atom. This reveals that the complex has the possibility as artificial nuclease.

• Bulletin of the Korean Chemical Society
• /
• 제25권1호
• /
• pp.37-41
• /
• 2004

A new tridentate ligand incorporating a monoxime and thiosemi-carbozone moieties has been synthesized. Its copper(II), nickel(II) and palladium(II) complexes have been prepared and characteirzed by physical and spectral methods. Elemental analyses and spectroscopic data of the metal complexes are consistent with the formation of a mononuclear copper(II) complex and binuclear complex with both nickel(II) and palladium(II). In the copper(II) complex the fourth coordination site is occupied by nitrate ion. In the binculear complexes the fourth coordination site is occupied by the deprotonated oxime oxygen of the ligand coordinated to the other metal.

• Bulletin of the Korean Chemical Society
• /
• 제31권1호
• /
• pp.189-192
• /
• 2010

• Bulletin of the Korean Chemical Society
• /
• 제12권6호
• /
• pp.629-632
• /
• 1991

The rate constants for the formation and dissociation of nickel(II) and cobalt(II) complexes with mandelate have been determined by the pressure-jump relaxation study. The forward and reverse rate constants for the mandelate complex formation reactions were obtained to be $k_f=3.60{\times}10^4\;M^{-1}s^{-1}$ and $k_r=1.73{\times}10^2\;s^{-1}$ for the nickel(II), and $k_f=1.75{\times}10^5\;M^{-1}s{-1}$ and $2.33{\times}10^3\;s^{-1}$ for the cobalt(II) in aqueous solution of zero ionic strength ($(\mu{\to}0)\;at\;25^{\circ}C$. The results were interpreted by the use of the multistep complex formation mechanism. The rate constants evaluated for each individual steps in the multistep mechanism draw a conclusion that the rate of the reaction would be controlled by the chelate ring closure step in concert with the solvent exchange step in the nickel(II) complexation, while solely by the chelate ring closure step for the cobalt(II) complex.

• 분석과학
• /
• 제8권4호
• /
• pp.469-475
• /
• 1995

Di-2-pyridylmethanon 2-thiophenecarboxylie hydrazone(DPMTCH) was synthesized and used as a chromogenic reagent in the spectrophotometric determination of nickel in steel. The proton disc spectrophotometrically, were $pK_{a1}= 2.66$ and $pK_{a2}= 10.98$ ${\mu}=0.5(NaCl)$. Nickel(II) reacts with DPMTCH to form a 1:2 metal-2-ligand ratio complex, the xylene solution of which has an absorption maximum at 417 nm. Beer's law is obeyed over the range $0-1.17\;mg\;ml^{-1}$ of nickel(II). The molar absorptivity of the nickel(II) complex is $4.17{\times}10^4l\;mol^{-1}\;cm^{-1}$. The precision of the method was estimated for 4.7 mg of nickel(II), the coefficient of variation for 15 replicate determinations being 0.34%.

• Bulletin of the Korean Chemical Society
• /
• 제17권1호
• /
• pp.83-85
• /
• 1996

• Bulletin of the Korean Chemical Society
• /
• 제30권12호
• /
• pp.3101-3104
• /
• 2009

• Bulletin of the Korean Chemical Society
• /
• 제26권11호
• /
• pp.1861-1864
• /
• 2005

• 대한화학회지
• /
• 제32권6호
• /
• pp.536-542
• /
• 1988

새로 합성한 N-benzylisonitrosoacetylacetone imine(CH3-CO-CNOH-CNCH2${\phi}$-CH3, 이하 H-IAA-NBz)을 리간드로 하는 Nickel(Ⅱ) 착물을 합성하고, 원소분석, 적외선흡수스펙트럼, 핵자기공명스펙트럼, 전자스펙트럼 및 질량스펙트럼등 분광학적인 자료와 자기모멘트 측정으로부터 구조를 구명하였다. 이 착물은 상온에서 매우 안정하며, cis-형 및 trans-형의 기하이성질체가 존재한다. Nickel 이온과 리간드로 1 : 2로 결합한다. 결합된 두 리간드 중 한쪽 리간드는 isonitroso기의 질소원자와 이민의 질소원자가 Nickel(Ⅱ) 이온과 결합하여 5원고리를, 다른쪽 리간드는 isoniroso기의 산소원자와 이민의 질소원자가 Nickel(Ⅱ)이온과 결합하여 6원고리를 형성하여 4각평면구조를 만들고 있다.

• Bulletin of the Korean Chemical Society
• /
• 제34권11호
• /
• pp.3474-3476
• /
• 2013