• 대한화학회지
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• 제68권4호
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• pp.185-190
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• 2024

최근에 benzobisoxazole (BBO) 분자가 HOMO와 LUMO 에너지 준위를 각각 독립적으로 조절하는데 사용될 수 있다는 연구가 보고되었다. 이 연구에서는 이 흥미로운 BBO 분자의 특성을 치환기에 따른 치환기 효과를 정량적으로 조사하는데 이용해보았다. BBO 분자를 중심으로 π-컨쥬게이션 길이를 확장시켜 4개의 BBO 모델 시스템을(1BBO, 2BBO, 3BBO, 4BBO) 디자인하고 제안했다. 치환은 두 방향(x-축, y-축), 총 15개의 치환기가 고려되었다. DFT 방법으로 계산된 x-축 치환 LUMO 에너지 준위와 y-축 치환 HOMO 에너지 준위 사이의 강한 상관관계로부터, BBO 모델 시스템들이 치환기 효과를 표준화 할 수 있음을 밝혔다. 또한 3BBO 시스템의 x-축 치환 HOMO 에너지 준위가 치환기 효과의 순서를 규정하는데 가장 적합한 것을 입증했다. 우리가 제안한 방법은 어떤 임의의 치환기에 대한 치환기 효과를 예측하는데 활용 될 수 있고, 유기 센서나 유기 발광 다이오드 개발에 활용될 수 있다.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.963-966
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• 2013

• 수산해양교육연구
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• 제27권1호
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• pp.203-217
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• 2015

The purpose of the study is to explore leisure time use of older adults and find out relationships between active/passive leisure activities and socioeconomic backgrounds in order to prepare later life for homo hundred. The subjects were 336 adults aged 50 and over in Busan city, Korea. Results are as follows. First, the subjects spent more time in active leisure than passive. But ratio of passive leisure time is getting higher with age. Second, cognitive activities changed from reading, computing, internet to hobbies, card games with age. Third, participation of active leisure activities are related to age and socioeconomic backgrounds. From this study, lifelong education including leisure education should support older adults to redesign their later life for homo hundred. Second, leisure education should focus on increasing the ability of accepting and utilizing leisure opportunities for older adults. Third, the role of lifelong educator should be emphasized to involve education field more actively. Forth, lifelong education institutions should have the knowledge of the purposes and motivations of older adults who participate in order to provide proper programs continuously. The connection between lifelong education and leisure time use and activities would lead later life with the quality of life and active aging.

• Journal of Electrochemical Science and Technology
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• 제8권2호
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• pp.96-100
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• 2017

Iridium(III) bis(2-phenylpyridinato-$N,C^{2^{\prime}}$)acetylacetonate ($(ppy)_2Ir(acac)$), a green dopant used in organic light-emitting devices (OLEDs), was subjected to electrochemical characterization to estimate its formal oxidation potential ($E^{o^{\prime}}$), HOMO energy level ($E_{HOMO}$), electron transfer rate constant ($k^{o^{\prime}}$), and diffusion coefficient ($D_o$). The employed combination of voltammetric methods, i.e., cyclic voltammetry (CV), chronocoulometry (CC), and the Nicholson method, provided meaningful insights into the electron transfer kinetics of $(ppy)_2Ir(acac)$, allowing the determination of $k^{o^{\prime}}$ and $D_o$. The quasi-reversible oxidation of $(ppy)_2Ir(acac)$ furnished information on $E^{o^{\prime}}$ and $E_{HOMO}$, allowing the latter parameter to be easily estimated by electrochemical methods without relying on expensive and complex ultraviolet photoemission spectroscopic (UPS) measurements.

• BMB Reports
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• 제44권11호
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• pp.747-752
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• 2011

To investigate the effects of disulphide bond position on the salt resistance and lipopolysaccharide (LPS)-neutralizing activity of ${\alpha}$-helical homo-dimeric antimicrobial peptides (AMPs), we synthesized an ${\alpha}$-helical model peptide ($K_6L_4W_1$) and its homo-dimeric peptides (di-$K_6L_4W_1$-N, di-$K_6L_4W_1$-M, and di-$K_6L_4W_1$-C) with a disulphide bond at the N-terminus, the central position, and the C-terminus of the molecules, respectively. Unlike $K_6L_4W_1$ and di-$K_6L_4W_1$-M, the antimicrobial activity of di-$K_6L_4W_1$-N and di-$K_6L_4W_1$-C was unaffected by 150 mM NaCl. Both di-$K_6L_4W_1$-N and di-$K_6L_4W_1$-C caused much greater inhibitory effects on nitric oxide (NO) release in LPS-induced mouse macrophage RAW 264.7 cells, compared to di-$K_6L_4W_1$-M. Taken together, our results indicate that the presence of a disulphide bond at the N- or C-terminus of the molecule, rather than at the central position, is more effective when designing salt-resistant ${\alpha}$-helical homo-dimeric AMPs with potent antimicrobial and LPS-neutralizing activities.

• Transactions on Electrical and Electronic Materials
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• 제10권1호
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• pp.24-27
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• 2009

N-doped ZnO thin films were deposited on n-type Si(100) and homo-buffer layer, and undoped ZnO thin film was also deposited on homo-buffer layer by RF magnetron sputtering method. After deposition, all films were in-situ annealed at $800^{\circ}C$ for 5 minutes in ambient of $O_2$ with pressure of 10Torr. X -ray diffraction shows that the homo-buffer layer is beneficial to the crystalline of N-doped ZnO thin films and all films have preferable c-axis orientation. Atomic force microscopy shows that undoped ZnO thin film grown on homo-buffer layer has an evident improvement of smoothness compared with N-dope ZnO thin films. Hall-effect measurements show that all ZnO films annealed at $800^{\circ}C$ possess p-type conductivities. The undoped ZnO film has the highest carrier concentration of $1.145{\times}10^{17}cm{-3}$. The photoluminescence spectra show the emissions related to FE, DAP and many defects such as $V_{Zn}$, $Zn_O$, $O_i$ and $O_{Zn}$. The p-type defects ($O_i$, $V_{Zn}$, and $O_{Zn}$) are dominant. The undoped ZnO thin film has a better p-type conductivity compared with N-doped ZnO thin film.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.2970-2972
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• 2011

One-pot homo- and cross-coupling reactions of arenediazonium tosylate salts bearing a halogen group have been exploited for the synthesis of biaryls and polyaryls under mild conditions. $Pd(OAc)_2$ has proven to be an efficient catalyst for the successful dual transformation of diazonium salts into p-quaterphenyl (3).

• 한국염색가공학회지
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• 제25권1호
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• pp.7-12
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• 2013

The energy levels are very important to investigate properties of organic dye materials. These values of energy levels can be calculated and compared with absorption spectra, cyclic voltammetric measurement and computer simulative calculation. In this study, absorption and emission changes were observed by complexation between rhodamine 6G based dye and mercury. This is related to spirolactam ring system of rhodamine 6G based dye. According to structural change of this dye, HOMO and LUMO energy levels were investigated and determined by their values with different approaches.

• 한국염색가공학회지
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• 제25권1호
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• pp.1-6
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• 2013

Nowdays, the computational simulation of molecular energy potentials and the empirical evidence using electrochemical reduction/oxidation values are very significant factors to predict of molecule's energy potentials. The prepared chemosensor herein consists of spirolactam ring system in the structure, providing intra-structural change with metal cation binding. In this study, rhodamine 6G-Naphthaldehyde chemosensor was determined and compared with HOMO/LUMO energy levels by computational calculation and cyclic voltammogram method.

• Advances in environmental research
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• 제1권4호
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• pp.257-276
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• 2012

QSAR models for chlorinated alkenes were developed between $E_{HOMO}$ and their chlorine and carbon content. The aim is to provide valid QSAR model which is statistically validated for $E_{LUMO}$ prediction. Different molecular descriptors, $N_{Cl}$, $N_C$ and $E_{HOMO}$ have been used to take into account relevant information provided by molecular features and physicochemical properties. The best model were selected using Partial Least Square (PLS) and Multiple Linear Regression (MLR) led to models with satisfactory predictive ability for a data set of 15 chlorinated alkene compounds.