Yunjung Baek
Korea Advanced Institute of Science and Technology · 材料科学
研究室紹介
Professor Yunjung Baek's research lab specializes in the development and application of transition metal complexes, particularly cobalt and iridium systems, for catalysis and photoredox processes. The lab focuses on designing stable, low-valent metal complexes with tailored ligand environments to enable unique reactivity, including C–H amination, azide transformations, and ligand-functionalization reactions. A key theme is the isolation and characterization of reactive intermediates such as Co(I) and Co(III) imido species, as well as reduced photosensitizers, to elucidate mechanistic pathways in catalysis and photochemistry. The lab also explores the electronic and photophysical tuning of synthetic flavins for advanced optoelectronic and biochemical applications.
Research Overview
Research Output Trend
Figures are computed from collected data and may differ slightly.
Selected Papers
15Reduction of (<sup>Ar</sup>L)Co<sup>II</sup>Br (<sup>Ar</sup>L = 5-mesityl-1,9-(2,4,6-Ph<sub>3</sub>C<sub>6</sub>H<sub>2</sub>)dipyrrin) with potassium graphite afforded the novel Co<sup>I</sup> synthon (<sup>Ar</sup>L)Co<sup>I</sup>. Treatment of (<sup>Ar</sup>L)Co<sup>I</sup> with a stoichiometric amount of various alkyl azides (N<sub>3</sub>R) furnished three-coordinate Co<sup>III</sup> alkyl imidos (<sup>Ar</sup>L)Co(NR), as confirmed by single-crystal X-ray diffraction (R: CMe<sub>2</sub>Bu
Treatment of (<sup>Ar</sup>L)CoBr (<sup>Ar</sup>L = 5-mesityl-1,9-(2,4,6-Ph<sub>3</sub>C<sub>6</sub>H<sub>2</sub>)dipyrrin) with a stoichiometric amount of 1-azido-4-(<i>tert</i>-butyl)benzene N<sub>3</sub>(C<sub>6</sub>H<sub>4</sub>-<i>p</i>-<sup><i>t</i></sup>Bu) furnished the corresponding four-coordinate organoazide-bound complex (<sup>Ar</sup>L)CoBr(N<sub>3</sub>(C<sub>6</sub>H<sub>4</sub>-<i>p</i>-<sup><i>t</i></sup>Bu)). Spectroscopic and structural characterization of the complex indicat
We report the catalytic C-H amination mediated by an isolable Co<sup>III</sup> imido complex (<sup>Tr</sup>L)Co(NR) supported by a sterically demanding dipyrromethene ligand (<sup>Tr</sup>L = 5-mesityl-1,9-(trityl)dipyrrin). Metalation of (<sup>Tr</sup>L)Li with CoCl<sub>2</sub> in THF afforded a high-spin (<i>S</i> = 3/2) three-coordinate complex (<sup>Tr</sup>L)CoCl. Chemical reduction of (<sup>Tr</sup>L)CoCl with potassium graphite yielded the high-spin (<i>S</i> = 1) Co<sup>I</sup> synthon (
One-electron reduced photosensitizers have been invoked as crucial intermediates in photoredox catalysis, including multiphoton excitation and electrophotocatalytic processes. However, such reduced chromophores have been less investigated, limiting mechanistic studies of their associated electron transfer processes. Here, we report a total of 11 different examples of isolable singly reduced iridium chromophores. Chemical reduction of a cyclometalated iridium complex with potassium graphite affor
Abstract The reactivity of ( Tr L)Co ( Tr L=5‐mesityl‐1,9‐(trityl)dipyrrin) toward various aryl azides was examined to elucidate the electronic structure and reactivity of dipyrrinato cobalt aryl nitrenoid complexes. Herein, we demonstrate the synthesis of a Co II diketimide complex [( Tr L)Co(NC 6 F 5 )] 2 and its reversible C−C bond cleavage to yield a monomeric Co nitrenoid complex ( Tr L)Co(NC 6 F 5 ). Exposure of [( Tr L)Co(NC 6 F 5 )] 2 to an excess amount of an H‐atom donor cleanly afford
Inspired by the prominent redox and optical properties of natural flavins, synthetic flavins have found broad applications in organic, photochemical, and biochemical research. Tailoring these properties of flavins, however, remains a challenge. In this work, we present three pentacyclic flavins (C-PF, O-PF, and S-PF) that leverage a strategic molecular design to modify the flavin’s electronic structure. Notably, the oxygen- and sulfur-linked pentacyclic flavins (O-PF and S-PF) exhibit deep-red a
High Resolution Image Download MS PowerPoint Slide Flavins─one of nature’s most ubiquitous organic cofactors─mediate proton and electron transfers in biological systems. Their heterocyclic (iso)alloxazine cores enable such reactivity through pronounced electro- and photochemical properties, as well as hydrogen bonding with surrounding residues. To harness these features in an organometallic context, we developed a redox-active, flavin-derived bidentate ligand ( all LH ) that engages both primary
Abstract The reactivity of ( Tr L)Co ( Tr L=5‐mesityl‐1,9‐(trityl)dipyrrin) toward various aryl azides was examined to elucidate the electronic structure and reactivity of dipyrrinato cobalt aryl nitrenoid complexes. Herein, we demonstrate the synthesis of a Co II diketimide complex [( Tr L)Co(NC 6 F 5 )] 2 and its reversible C−C bond cleavage to yield a monomeric Co nitrenoid complex ( Tr L)Co(NC 6 F 5 ). Exposure of [( Tr L)Co(NC 6 F 5 )] 2 to an excess amount of an H‐atom donor cleanly afford
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.