============================================================== 제 목 : Physical-Organic Approaches to Studying Protein Chemistry 연 사 : Prof. Kyungtae Kang(Department of Applied Chemistry, Kyung Hee University) 일 시 : 2017년 4월 13일(목) 오후 4시 30분 장 소 : 화학관 2층 서병인 강의실 (330226호실) ============================================================== Physical-Organic Approaches to Studying Protein Chemistry Kyungtae Kang Department of Applied Chemistry, Kyung Hee University, 1732 Dyeogyoung-daero, Giheung-gu, Youngin, Gyeonggi 17104, Republic of Korea Biomolecular recognition is governed as much by rearrangements of the water that hydrates the interacting molecules as it is governed by their direct interactions. A detailed understanding of the mechanisms by which these rearrangements contribute to the thermodynamics of recognition processes is, thus, essential for better understanding—and predicting—the energetics of important biomolecular recognitions. In this respect, the hydrophobic effect—the tendency of nonpolar surfaces to associate in aqueous solution—is one of the major driving forces of many biomolecular recognition events. The hydrophobic effect arises from free energetically favorable rearrangements of water, whose thermodynamic consequences are fairly well understood for flat, nonpolar entities in aqueous solution (where the intermolecular association of such entities gives rise to the entropically favorable, enthalpically unfavorable release of ordered waters from their surfaces), but incompletely understood—and difficult to predict—for interactions between ligands and the morphologically complex and chemically heterogeneous binding pockets of proteins. In this talk, I will introduce our efforts to examine the role of water filling the binding pocket of human carbonic anhydrase II (HCAII, EC 4.2.11) in its bindings with structurally varied sulfonamide ligands, by combining isothermal titration calorimetry, X-ray crystallography, site-directed mutagenesis, and molecular dynamics simulations. By this set of methods, we showed that (i) the hydrophobic surface area of a ligand does not improve DGºb, unless that increased non-polar area is buried in the binding process, and values of DHºb and -TDSºb depend on the structure (or morphology) of a ligand; (ii) reorganizing networks of water inside the binding pocket by mutating amino acids thereof brings about huge and compensating changes in values of DHºband -TDSºb. References 1. D. Chandler, Nature437, 640 (2005). 2. P. W. Snyder, M. R. Lockett, D. T. Moustakas, G. M. Whitesides, Eur. Phys. J.-Spec. Top. 223, 853 (2013).
===================================================================================== 제 목 : Chiral Tetrahydrothiophene Ligands in Asymmetric Catalysis 연 사 : Prof. Rong-Jie Chein(Institute of Chemistry, Academia Sinica) 일 시 : 2017년 4월 4일(화) 오후 4시 30분 장 소 : 화학관 1층 강의실 (330118호실) ===================================================================================== Chiral Tetrahydrothiophene Ligands in AsymmetricCatalysisRong-Jie CheinInstitute of Chemistry, Academia Sinica, Nankang, Taipei 11529, TaiwanE-mail: firstname.lastname@example.org Chiral sulfur ligands are becoming a versatile tool in organic chemistry due to theblossomed development achieved in the past years. This presentation describes anexpeditious and efficient preparation of enantiopure (thiolan-2-yl)diarylmethanols andthe applications of their derivatives to catalytic and asymmetric Corey-Chaykovskyepoxidation,1 the imino Corey-Chaykovsky aziridination,2,3 as well as the firstoxathiaborenium catalyzed asymmetric Diels-Alder reaction.4,5 Figure 1. Synthesis and applications of chiral THT ligands Reference1. Wu, H.-Y.; Chang, C.-W.; Chein, R.-J. J. Org. Chem. 2013, 78, 5788-5793.2. Huang, M.-T.; H.-Y. Wu; Chein, R.-J. Chem. Commun. 2014, 50, 1101-1103.3. Wang, S.-H.; Chein, R.-J. Tetrahedron, 2016, 72, 2607-2615..4. Kumar, S. N.; Yu, I. F.; Chein, R.-J. Org. Lett. 2017, 19, 22-25. (Highlighted byC&EN 2017, 95(1), 9).5. Tsai, M.-L.; Chein, R.-J. to be submitted.Rong-Jie Chein (陳榮傑), National Chiao Tung University (Ph.D., 2005), HarvardUniversity (Postdoctoral Fellow, E. J. Corey Lab, Jan. 2007 - June 2009). AssistantResearch Fellow of Academia Sinica (July 2009 - May 2015). Associate ResearchFellow (May 2015 - ). Research fields: (1) Development of new synthetic strategiesand methods. (2) Total synthesis and the study of the chemistry and biology of naturalproducts and designed molecules.
============================================================== 제 목 : Soft Matter at Rubbing Interfaces: Lessons from Nature to Design Water-friendly Tribosystems 연 사 : 이승환 교수님(Technical University of Denmark) 일 시 : 2017년 3월 30일(목) 오후 4시 30분 장 소 : 화학관 2층 서병인강의실 (330226호실) ============================================================== Soft Matter at Rubbing Interfaces: Lessons from Nature to Design Water-friendly Tribosystems Seunghwan Lee Department of Mechanical Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark Life-long maintenance of biotribosystems, such as synovial joints, ocular tracts, and oral cavity, is remarkable and even puzzling considering that the base stock for the lubrication is water. For most man-made engineering systems, water is generally excluded as lubricant due to its poor capabilities to withstand external loads on its own. Nature solves this problem by incorporating pressure-responsive, “smart coatings”, such as mucus gel layers on the surface, and thus facilitate the entrainment and retainment of water (lubricant) at the rubbing interfaces. Mucins, a family of high-molecular-weight glycoproteins and a main macromolecular constituent of mucus gels, are interesting also because they show unique slipperiness at the interface composed of synthetic materials too. This, in turn, has inspired the development of mucin-like, brush-forming synthetic polymers, which can be applied in the lubrication of engineering materials with water. Biophysical properties of both mucinous glycoproteins and their mimics, brush-forming polymers, are very sensitive to environmental changes, and this feature can be exploited to optimize their properties for particular applications. Studies on soft matter at the rubbing interfaces firstly help understand the biological mechanisms of lubrication and provide useful hints for biomimetic lubrication engineering. Furthermore, various fundamental properties of soft matter on surface can be revealed only by being exposed to interfacial shear stresses. This talk will provide an overview on recent researches on the conformation, surface adsorption, and biotriobological properties of mucins/mucus gels with varying origin, purity, and environment as well as synthetic brush-like polymer chains, including poly(ethylene oxide)(PEO)-based copolymers, carbohydrate-based copolymers, and polyeletrolyte-based copolymers.
================================================== 제 목 : Quantum simulation of molecular problems 연 사 : 허준석 교수님(성균관대학교 화학과) 일 시 : 2017년 3월 9일(목) 오후 4시 30분 장 소 : 화학관 세미나실 (330226호실) ================================================== Quantum simulation of molecular problems Joonsuk Huh Department of Chemistry, Sungkyunkwan University The intrinsic nature of parallelism of quantum states is anticipated to give extraordinary computational power to quantum processors for certain problems. A linear optical network is one of the simplest quantum processors that it could reveal the (computational) quantum supremacy against classical machines. A photon-sampling problem in a linear optical network, so-called Boson Sampling, is a specially designed mathematical problem, which is expected to be intractable for any classical machine. In my talk, I will present what we can do with the photonic quantum simulator (non-universal quantum computer) practically. Boson Sampling is generalized with Gaussian input states to simulate the molecular vibronic spectroscopy [1-5].  J. Huh, G. G. Guerreschi, B. Peropadre, J. R. McClean, and A. Aspuru-Guzik. Boson Sampling for Molecular Vibronic Spectra. Nature Photon. 9 (2015): pp 615-620.  J. Huh and M.-H, Yung, Hierarchy in Sampling Gaussian-correlated Bosons, Preprint: arXiv:1608.03731.  Y. Shen, J. Huh, Y. Lu, J. Zhang, K. Zhang, S. Zhang and K. Kim, Quantum simulation of molecular spectroscopy in trapped-ion device, Preprint: arXiv:1702.04859  D. G Olivares, B. Peropadre, J. Huh and J. J. García-Ripoll, Quantum emulation of molecular force fields: A blueprint for a superconducting architecture Preprint: arXiv:1611.08101  B. Peropadre, J. Huh and C. Sabin, Dynamical Casimir effect for boson sampling, Preprint: arXiv:1610.07777
============================================================== <세미나1> 제 목 : Visible Light-Induced Radical Transformations 연 사 : 조은진 교수님(중앙대학교) 일 시 : 2016년 12월 8일(목) 오후 4시 장 소 : 화학관 2층 세미나실(330226호실) ============================================================== Visible Light-Induced Radical Transformations Eun Jin Cho Department of Chemistry, Chung-AngUniversity, Seoul 06794, Republic of Korea E-mail:email@example.com Recently, visible light photocatalysis has attracted substantial attention due to its environmental compatibility and mechanistic versatility in promoting a large number of synthetically important reactions. We have developed a variety of radical transformations using Ru-, Ir-, and Pt-based photocatalysts under visible light irradiation. Fluoroalkylated organic compounds play significant roles in the pharmaceutical, agrochemical, and material sciences owing to the substantial influence that fluorine substitution has on the physical and chemical properties of substances. Visible light-induced methods allowed access to fluoroalkyl group-containing molecules, such as –CF2R, –CF3,and –CF2SPh groups.1 In the studies, electron deficient carbon-centered fluoroalkyl radicals were successfully generated by the appropriate choice of fluoroalkyl source, photocatalyst, additives, and solvent. Notably, we have observed that additives significantly affect the efficiencies and selectivities of these reactions and can even change the outcome of the reaction by playing additional roles during its course. By understanding the roles of additives, we developed several controlled fluoroalkylation reactions of alkenes and alkynes where different products were formed selectively from the same starting substrates.2-4 Polyheteroaromatic compounds have also attracted much attention due to their unique p-conjugation, which make them suitable functional materials in many applications. The synthesis of carbazole motif has been accomplished using N-substituted amidobiaryls through the merger of photoredox and palladium catalysis.5 The use of 1 mol% of an Ir-photocatalyst obviated the typical high loadings of external chemical additives in the transformation. And recently, we synthesized a new class of polyheteroaromatics from the coupling process between readily accessible 2-heteroaryl substituted aromatic amines and heteroaromatic alkynes by an Ir-catalyzed visible light photocatalysis.6 [References] Chatterjee, T.; Iqbal, N.; You, Y.; Cho, E. J.Acc. Chem. Res. 2016, 49, 2284-2294. Iqbal, N.; Jung, J.; Park, S.; Cho, E. J. Angew. Chem. Int. Ed. 2014, 53, 539-542. Yu, C.; Iqbal, N.; Park, S.; Cho, E. J. Chem. Commun. 2014, 50, 12884-12887. Choi, Y.; Yu, C.; Kim, J. S.; Cho, E. J. Org. Lett. 2016, 18, 3246-3249. Choi, S.; Chatterjee, T.; Choi, W. J.; You, Y.; Cho, E. J. ACS Catalysis, 2015, 5, 4796-4802. Chatterjee, T.; Choi, M. G.; Kim, J.; Chang, S.-K.; Cho, E. J. Chem. Commun. 2016, 52, 4203-4206. ============================================================== <세미나2> 제 목 : Iron Catalysis:from High-valent Lewis Acid Catalyst to Low-valent Redox Catalyst 연 사 : 강은주 교수님(경희대학교) 일 시 : 2016년 12월 8일(목) 오후 5시 장 소 : 화학관 2층 세미나실(330226호실) ============================================================== Iron Catalysis: from High-valent Lewis Acid Catalyst to Low-valent Redox Catalyst Eun Joo Kang e-mail: firstname.lastname@example.org The use of iron compounds as catalysts in organic synthesis is attractive for a number of reasons. It is the most abundant metal in the earth’s crust after aluminum and therefore is much cheaper than the precious metals that are often applied. Regarding the catalytic efficiency and broad applicability, at present iron is still behind palladium as the most versatile catalytic metal, however, the tremendously increasing number of publications demonstrates that iron is catching up. Unlikely palladium, iron can adopt ocidation states from -2 to +5, thus, in low oxidation states it may be operative as an iron-centered nucleophile and catalyze nucleophilic substitutions and additions. In contrast, iron Lewis acid catalyzed reactions have been known for a long time, for example electrophilic aromatic substitutions. Haaving this potential in mind, our lab has been interested in alternative use of iron catalysis in the following organic synthesis. First, we reported Fe catalyzed atom-economical tandem reaction of alkene-iodide in the present of equimolar aryl Grignard reagent. Aryl Grignard reagent is used to generate Fe-Grignard complex and the counter aryl anion is used in the further cross-coupling, thereby affording the tandem cyclization/cross-coupling radical reaction. Also, the nucleophilic cyclization reactions of allenes were catalyzed by Fe(III) to afford the corresponding heterocycle compound. Fe(III) catalysts were applied in the reactions of allenyl amides or allenyl alcohols and cyclized compounds containing O or N heteroatom were produced with moderate to good yields.
============================================================ 제 목 : Development of Metal-Catalyzed Direct C-H Amination Reactions 연 사 : 장석복 교수(KAIST) 일 시 : 2016년 12월 1일(목) 오후 4시 15분 장 소 : 화학관 첨단강의실(330118호) ----------------------------------------------------------- Development of Metal-Catalyzed Direct C-H Amination Reactions Sukbok Chang Institute for Basic Science (IBS), Daejeon 305-701, Korea Department of Chemistry, Korea Advanced Institute of Science & Technology (KAIST), Daejeon 305-701, South Korea E-mail: email@example.com The mechanism of the Ir(III) and Rh(III)-mediated C–N coupling reaction, which is the key step of catalytic C-H amidation, was investigated in an integrated experimental and computational study. Novel amidating agents containing a 1,4,2-dioxazole moiety allowed for designing a stoichiometric version of the catalytic C–N coupling reaction and giving access to reaction intermediates that reveal details about each step of the reaction. Both DFT and kinetic studies strongly point to a mechanism where the M(III) complex engages the amidating agent via oxidative coupling to form a M(V)-imido intermediate, which then undergoes migratory insertion to afford the final C–N coupled product. For the first time, the stoichiometric versions of the Ir and Rh-mediated amidation reaction were compared systematically to each other. Iridium reacts much faster than rhodium (~ 1100 times at 6.7 oC) with the oxidative coupling being so fast that the activation of the initial Ir(III)-complex becomes rate-limiting. In the case of Rh, the Rh-imido formation step is rate-limiting. These qualitative difference stems from a unique bonding feature of the dioxazole moiety and the relativistic contraction of the Ir(V), which affords much more favorable energetics for the reaction. For the first time, a full molecular orbital analysis is presented to rationalize and explain the electronic features that govern this behavior.  S. H. Cho, J. Kim, J. Kwak, Sukbok Chang, Chem. Soc. Rev.2011, 40, 5068-5083  K. Shin, H. Kim, S. Chang, Acc. Chem. Res. 2015, 48, 1040-1052 Y. Park, K. T. Park, J. G. Kim, S. Chang, J. Am. Chem. Soc. 2015, 137, 4534-4542  W. Xie, J. H. Yoon, S. Chang, J. Am. Chem. Soc. 2016, 138, 12605-12614  Y. Park, J. Heo, M.-H. Baik, S. Chang, J. Am. Chem. Soc. 2016, 13
============================================================== 제 목 : 화학작용제 지속도 연구 연 사 : 임종선 부이사관(국군화학방어연구소) 일 시 : 2016년 11월 24일(목) 오후 3시 장 소 : 화학관 2층 세미나실 (330226호실) ============================================================== 화학작용제 지속도 연구 소형풍동장치를 이용하여 화학작용제의 증발 및 소멸특성의 연구를 통해 야전환경 조건 하 화학작용제의 지속도와 관련 데이터를 축적하고자 본 연구를 수행하였다. 실험에 사용한 화학작용제는 HD와 GD이며, 지표물질로는 비다공성 표면으로 유리, 다공성 표면으로 콘크리트 및 나지표면을 이용하여 실험을 진행하였다. 실험에 적용한 환경조건은 온도, 풍속, 오염량의 세가지 변수이며, 온도는 17℃ ~ 45℃, 풍속은 0.8km/h ~ 13km/h, 오염량은 1g/㎡ ~ 10g/㎡의 범위에서 실시하였다. 실험을 통해 획득한 데이터는 美 ECBC의 실험데이터와 비교하기 위해 ECBC에서 데이터를 처리한 방식대로 데이터를 처리해 비교를 실시하였다. 획득한 ECBC 데이터는 HD와 VX 데이터이다. 미국의 데이터와 비교하기 위해 작용제별 증발속도를 산출해 ECBC에서 제시한 증발속도 계산식을 이용하여 계산된 증발속도 값 및 실제 실험을 통해서 획득된 미국의 증발속도 데이터와 비교하였다. 또한, HD의 STEL(short-term exposure limit), VX의 IDLH(immediately dangerous to life or health) 농도에 해당하는 농도인 0.003mg/㎥에 도달될 때까지의 시간을 측정해 ECBC의 계산식에 의한 지속시간과 실제 데이터를 통해 산출한 지속시간도 같이 비교해 데이터의 신뢰성을 확인하였다. 지속도 데이터와 증기농도 및 흡입량을 기준으로한 위험기준을 토대로 지속시간 기준별 위험수준을 확인했고, 잔류량 분석을 통해 잔류위험을 확인하였다. 분석결과 화학작용제의 증기량이 미미한 시점에서도 잔류위험이 존재하는 것으로 확인되었다.
제 목 : Postsynthetic transmetalation of metal-organic frameworks
연 사 : 나명수 교수(UNIST)
일 시 : 2016년 11월 17일(목) 오후 4시 15분 장 소 : 화학관 첨단강의실(330118호)
Postsynthetic transmetalation of metal-organic frameworks
Myoung Soo Lah
Department of Chemistry, Ulsan National Institute of Science & Technology (UNIST)
50 Unist-gil, Ulju-gun, Ulsan, Korea 44919
Fax: +82-(52)-217-2019 E-mail address: firstname.lastname@example.org
The replacements of framework metal ions and ligands were investigated in metal–organic frameworks (MOFs). The transmetalated MOFs could be obtained by soaking an MOF in the solution of a new replacing metal ion. By simply controlling the soaking time, not only fully transmetalated isostructural framework structure but also selectively transmetalated core-shell bimetallic structure could be prepared. The ligand exchanged MOFs could also be obtained via soaking an MOF in the solution of a new replacing ligand. By controlling the concentration of the replacing ligand, not only an entropically favorable MOF with completely exchanged ligand but also enthalpically favorable MOF with selectively exchanged ligand in the alternating layers could be obtained. While there is no significant structural rearrangement of the framework during the replacement of the framework metal ion, the replacement of the framework ligand led to the significant structural reorganization of the framework.
행사명 : 대한화학회 경기지부 추계 심포지엄 행사일자 : 2016년 11월 10일(목) 오후 4시 개최장소 : 성균관대학교 자연과학캠퍼스 화학관 1층 첨단강의실 (330118호) 주최 : 대한화학회 경기지부 발표편수 : 교수 구두발표(3편) 담당자 : 차상원 교수(한국외국어대학교 화학과, email@example.com) 내용- 경기도 지역내 신진 연구자 연구분야 소개 및 학술활동 강화- 경기지부 회원 학문교류 및 친목 도모- 일정 4:00~4:30 등록 4:30~4:35 개회사 및 환영사 – 김연규 지부장 4:35~5:00 이안나 교수 (명지대 화학과) “Organocatalyzed Asymmetric Reactions” 5:00~5:25 강경태 교수 (경희대 응용화학과) “Behaviors of Neurons on Nanotopographies” 5:25~5:50 송창식 교수 (성균관대 화학과) “Sustainable Photoactive Polymer Systems Enabled by Metal-Terpyridine-based Self-Assembly” 5:50~6:00 폐회사 및 기념촬영
============================================================== <세미나1> 제 목 : Modeling of chemical and physical processes: towards a quantitative engineering approach– practical applications 연 사 : Prof. Phillipe Heynderickx(GHENT UNIVERSITY) <세미나2> 제 목 : Defect creation via synthesis procedure in metal-organic frameworks 연 사 : Prof. Francis.Verpoort(GHENT UNIVERSITY) 일 시 : 2016년 10월 26일(수) 오후 2시 30분 장 소 : 화학관 첨단강의실 (330118호실) ============================================================== <세미나1> Modeling of chemical and physical processes: towards a quantitative engineering approach– practical applications In the early days, researchers were relying on performed experiments to describe reality vialaboratory tests. For example in catalysis (blue triangle in given figure), materials were prepared,characterized in a physical way (e.g. XRD, TEM, BET…) or chemical way (selectivereactions). This practice gained power when computational possibilities were created via theuse of a computer. The next step in this natural process of research was to come up with kineticor physical models describing reality as adequate as possible, giving rise to chemical andphysical descriptors of this reality.Today, the research of Prof. Dr. ir. Philippe M. Heynderickx focuses on the green triangle inthe figure: a combination of catalytic testing of materials (MOFs for e.g. selective adsorptionor fine-chemical reactions or metal oxides catalysts for e.g. selective oxidation reactions), thecorresponding kinetic modeling via fundamental reaction steps using intrinsic data and theupscaling to industrial proportion via reactor simulation.The long-term strategy is the development, construction and implementation of intrinsic kineticmodels describing catalytic reactions for daily relevant applications. Especially environmentalapplications in ‘green chemistry’ conversion, environmental sensors, catalysis andenergy storage applications are envisaged. ------------------------------------------------------------------------------------------- <세미나2> Defect creation via synthesis procedure in metal-organic frameworks Francis Verpoort1,2,3,4, 1 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing; Center for Chemical and Material Engineering, Wuhan University of Technology, Wuhan 430070, P.R. China 2 School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, P.R. China. 3 Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000, Ghent, Belgium 4Ghent University, Global Campus Songdo, 119 Songdomunhwa-Ro, Yeonsu-Gu, Incheon, Korea *E-mail: Francis@whut.edu.cn / Francis.firstname.lastname@example.org The variation in synthesis procedure, such as solvothermal, room temperature, microwave and spray drying, for metal-organic frameworks (MOFs) effluences the structure, morphology and properties of the MOF materials such as crystal sizes, particle shape, surface area, defect structures (defects) and gas adsorption properties of N2, CO2, CH4 etc. This work describes procedures to synthesize MOFs exposing dramatically different properties compared with the same MOFs prepared in a conventional manner. These results were deduced and supported from crystal morphologies which are related to the rate of crystallization or crystal growth, from surface and porosity properties evaluation from adsorption measurements, and from temperature decomposition analysis. Furthermore, the crystal framework keeps the same structure as proven from the XRD pattern and coordination functional group analysis (Fig.1). The diversity of defect structures correlates with active sites and thus also with the catalytic performance which is confirmed via example of catalytic reactions. The high catalytic performance of MOFs from this invention is related to the presence of more acid and basic sites occurring on defect structure. Knowledge of the nature and amount of defects is of utmost importance to decide which MOF is suitable for a certain catalytic reaction. Fig1. The synthesis ZIF-8 by different procedure (Spray drying: ZIF-8-SP, Microwave: ZIF-8-MW, Room temperature: ZIF-8-RT, Solvothermal: ZIF-8-SV) and their accompanying XRD patterns (a) The crystal morphology, shape and size investigated by SEM technique (b). The crystal morphology evolution with rate of crystallization effluence of procedure in MOFs synthesis from rapid to slowing growth (top to down direction) present the cube shape to rhombic dodecahedron shape (c). S. Chaemchuen, N.A. Kabir, K. Zhou, F. Verpoort, Chem. Soc. Rev. 42, 9304-9332 (2013). Z. Fang, B. Bueken, D.E. De Vos, R.A. Fischer, Angew. Chem. Int. Ed.54, 7234-7254 (2015)