https://scholar.dgist.ac.kr/handle/20.500.11750/55 2026-04-04T14:58:21Z https://scholar.dgist.ac.kr/handle/20.500.11750/59007 Title: Mononuclear copper-alkylperoxo complexes in stoichiometric and catalytic reactions Author(s): Cho, Jaeheung Abstract: Mononuclear transition metal alkylperoxo complexes are important in diverse biological and catalytic oxidation processes. Among them, a number of Cu(II)-alkylperoxo species have been characterized and some of these complexes served as models of lipid peroxidation. Herein, we report the first example of Cu(II)-alkylperoxo complexes that affect aldehyde deformylation with an oxidative nucleophilic character and the kinetics of aldehyde deformylation by Cu(II)-alkylperoxo species at low temperature. The mononuclear Cu(II)-alkylperoxo complexes are characterized by various physicochemical methods such as UV-vis, CSI-MS, resonance Raman and EPR. Particularly, EPR data clearly exhibit tetragonal geometry of Cu(II)-alkylperoxo complexes, which was in good agreement with the results of DFT calculations. Interestingly, the Cu(II)-alkylperoxo complexes exhibit different reactivity at higher temperature, where the Cu(II)-alkylperoxo complexes are capable of catalyzing C-H bond activation (i.e., electrophilic reaction). 2017-08-19T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58987 Title: Mononuclear metal-O2(H) adducts in oxidative nucleophilic and electrophilic reactions Author(s): Cho, Jaeheung 2016-03-12T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/17202 Title: Challenges of Measuring Soluble Mn(III) Species in Natural Samples Author(s): Kim, Bohee; Lingappa, Usha Farey; Magyar, John; Monteverde, Danielle; Valentine, Joan Selverstone; Cho, Jaeheung; Fischer, Woodward Abstract: Soluble Mn(III)–L complexes appear to constitute a substantial portion of manganese (Mn) in many environments and serve as critical high-potential species for biogeochemical processes. However, the inherent reactivity and lability of these complexes—the same chemical characteristics that make them uniquely important in biogeochemistry—also make them incredibly difficult to measure. Here we present experimental results demonstrating the limits of common analytical methods used to quantify these complexes. The leucoberbelin-blue method is extremely useful for detecting many high-valent Mn species, but it is incompatible with the subset of Mn(III) complexes that rapidly decompose under low-pH conditions—a methodological requirement for the assay. The Cd-porphyrin method works well for measuring Mn(II) species, but it does not work for measuring Mn(III) species, because additional chemistry occurs that is inconsistent with the proposed reaction mechanism. In both cases, the behavior of Mn(III) species in these methods ultimately stems from inter-and intramolecular redox chemistry that curtails the use of these approaches as a reflection of ligand-binding strength. With growing appreciation for the importance of high-valent Mn species and their cycling in the environment, these results underscore the need for additional method development to enable quantifying such species rapidly and accurately in nature. © 2022 by the authors. Licensee MDPI, Basel, Switzerland. 2022-02-28T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/16748 Title: 광분해성 코발트 나이트로실 착물 및 이를 포함하는 일산화질소 전달체 Author(s): 서대하; 조재흥; 최지수