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| Type |
Poster Presentation |
| Area |
무기화학 |
| Room No. |
포스터발표장 |
| Time |
4월 21일 (금요일) 13:00~14:30 |
| Code |
INOR.P-61 |
| Subject |
Synthesis, characterization, and catalytic activities of nickel(II) monoamido-tetradentate complex: Evidence for NiIII-Oxo and NiIV-Oxo species |
| Authors |
안혜미, 정하영, 김 철1,*
서울과학기술대학교 정밀화학과, Korea
1서울과학기술대학교 정밀화학과 친환경소재제품센터, Korea
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| Abstract |
A new mononuclear nickel(II) complex, [Ni(II)(dpaq)Cl] (1), containing a tetradentate monoamido ligand, dpaq (dpaq=2-(bis(pyridin-2-ylmethyl)amino)-N-(quinolin-8-yl)acetamide), has been synthesized and characterized by IR, elemental analysis, and UV-visible spectroscopy. The structure of the nickel complex has been determined by X-ray crystallography. This nonheme NiII complex 1 catalyzed epoxidation reaction of a wide range of olefins with meta-chloroperoxybenzoic acid (MCPBA) under mild conditions. Olefin epoxidation by this catalytic system has been proposed to involve a new reactive NiIV-Oxo (4) species, based on the evidence from PPAA (peroxyphenylacetic acid) probe, Hammett studies, H218O-exchange experiments, and ESI-mass spectroscopic analysis. Moreover, the nature of solvent significantly influenced partitioning between heterolytic and homolytic O-O bond cleavage of Ni-acylperoxo intermediate (2). The O-O bond of the Ni-acylperoxo intermediate 2 proceeded predominantly via heterolytic cleavage in a protic solvent such as CH3OH. These results suggested that possibly NiIV-Oxo species was a common reactive intermediate in protic solvents. The two active oxidants, viz. NiIV-Oxo (3) and NiIII-Oxo (4), which are responsible for stereospecific olefin epoxidation and radical-type oxidations, respectively, operate in aprotic solvents. |
| E-mail |
ahnhyemi0602@naver.com |
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119th General Meeting of the KCS