• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.4
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• pp.366-371
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• 2022

Recently many efforts have been made to develop a novel class of non-fullerene electron acceptor materials for high-performance organic solar cells. In this work, anthraquinone derivatives, TMAQ and THAQ, were prepared and their availability as electron acceptor materials for organic solar cells were investigated in terms of optical, thermal, electrochemical properties, and solar cell devices. Compared to TMAQ, a significant bathochromic shift of absorption band was observed for THAQ owing to intramolecular hydrogen-bond-assisted CT interactions. Thanks to the fused aromatic ring structure and benzoquinone unit, both TMAQ and THAQ exhibited a high thermal stability and an efficient electron reduction process. In particular, the intramolecular O-H---O=C hydrogen bond of THAQ plays an important role in improving the thermal stability and electron reduction properties. In the P3HT:acceptor solar cell system, THAQ-based devices had more than ca. 6 times higher power conversion efficiency than TMAQ -based devices. These results serve as a guide for developing high-efficient anthraquinone-based electron acceptor materials.

• Macromolecular Research
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• v.16 no.5
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• pp.446-456
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• 2008

A recent theoretical approach based on the coupling of both the Flory-Huggins (FH) and the Association Equilibria thermodynamic (AET) theories was modified and adapted to study the miscibility properties of a multi-component system formed by two polymers (a proton-donor and a proton-acceptor) and a proton-acceptor solvent, named copolymer(A)/solvent(B)/polymer(C). Compatibility between polymers was mainly attained by hydrogen-bonding between the hydroxyl group on the phenol unit of the poly(styrene-co-vinyl phenol) (PSVPh) and the carbonyl group of the biodegradable and environmentally friendly poly(3-hydroxybutyrate) (PHB). However, the self-association of PSVPh and specific interactions between the PSVPh and the H-acceptor group (an ether oxygen atom) of the epichlorohydrin (ECH) solvent were also established in a lower extension, which competed with the polymer-polymer association. All the binary specific interactions and their dependence with the system composition as well as with the copolymer content were evaluated and quantified by means of two excess functions of the Gibbs tree energy, ${\Delta}g_{AB}$ and ${\Delta}g_{AC}$. Experimental results from fluorescence spectroscopy were consistent with the theoretical simulations derived with the model, which could also be applied and extended to predict the miscibility in solution of any polymer blend with specific interactions.

• Bulletin of the Korean Chemical Society
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• v.20 no.3
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• pp.261-263
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• 1999

• Bulletin of the Korean Chemical Society
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• v.18 no.1
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• pp.18-23
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• 1997

Data from structure/activity studies in vir gene induction system have led to evaluate the working hypothesis of interaction between phenolic inducers and phenol binding proteins. The primary specificity in the association of a phenolic inducer with its receptor in our system is hypothesized to be the hydrogen bonding interactions through the ortho methoxy substituents as well as the proton transfer between the inducer and the binding protein. In this paper the proposed working model for phenol-mediating signal transduction was evaluated in several ways. The importance of the general acid-base catalysis was first addressed by the presence of an acidic residue and a basic residue in the phenol binding protein. Series of compounds were tested for vir gene expression activity to confirm the generation of a strong nucleophile by an acidic residue and an involvement of a basic residue as a proton acceptor. An attempt was made to correlate the pKa values of the phenolic compounds with vir gene induction activities as inducers to further support the proposed proton transfer mechanism. Finally, it was also observed that the regioselectively attached methoxy group on phenol compounds is required as the proper hydrogen bond acceptor.

• Journal of the Korean Chemical Society
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• v.57 no.1
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• pp.99-103
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• 2013

The present communication deals with the Pharmacophore modeling, 3D QSAR and docking analysis on series of Pyrimidine derivatives as potential calcium channel blockers. The computational studies showed hydrogen bond donor, hydrogen bond acceptor, and hydrophobic group are important features for calcium channel blocking activity. These studies showed that Pyrimidine scaffold can be utilized for designing of novel calcium channels blockers for CVS disorders.

• Bulletin of the Korean Chemical Society
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• v.2 no.1
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• pp.8-11
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• 1981

A new potential function based on spectroscopic results for diatomic molecules is presented and applied to the hydrogen bonding systems. The potential energy of interaction is supposed to have electrostatic, polarization, dispersion, repulsion and effective charge-transfer contributions. Estimates of the effective charge-transfer quantity have been made based on the average charge of the proton donor and the acceptor atoms. For dimers such as water, methanol, acetic acid and formic acid, the vibrational stretching frequencies and dimerization energies are calculated and dicussed in connection with Badger-Bauer rule.

• Carbon letters
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• v.12 no.2
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• pp.112-115
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• 2011

The scope of this work investigates the relationship between the amount of oxygen-functional groups and hydrogen adsorption capacity with different concentrations of phosphoric acid. The amount of oxygen-functional groups of activated carbons (ACs) is characterized by X-ray photoelectron spectroscopy. The effects of chemical treatments on the pore structures of ACs are investigated by $N_2$/77 K adsorption isotherms. The hydrogen adsorption capacity is measured by $H_2$ isothermal adsorption at 298 K and 100 bar. In the results, the specific surface area and pore volume slightly decreased with the chemical treatments due to the pore collapsing behaviors, but the hydrogen storage capacity was increased by the oxygen-functional group characteristics of AC surfaces, resulting from enhanced electron acceptor-donor interaction at interfaces.

• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.802-804
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• 2005

• Microbiology and Biotechnology Letters
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• v.5 no.3
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• pp.141-151
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• 1977

Distribution of tellurite and tellurate-reducing enzymes in the cell of Nocardia sp, the purifcation and the chemical properties of enzymes were investigated. Tellurite- and tellurate-reducing enzymes were located in the cytoplasm, but T. T. C. reduction part was in the cell membrane. Purification of tellurite- and tellurate-reducing enzymes was possible with the application of ammonium sulfate precipitation method and DEAE-Cellulose or CM-Cellulose column chromatographic method from the crude soluble part of the cell. On investigating the properties of purified enzyme, one of NADP, NADPH and reductive methylene blue(leucomethylene blue) was thought to react as a hydrogen donor. Both NADH and NADPH, or either of them would be physiological hydrogen donor.) In the reaction of this enzyme, either tellurite or tellurate reacts as a hydrogen acceptor, but on the other hand either selenate or selenate also reacts as a hydrogen acceptor.

• Analytical Science and Technology
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• v.36 no.3
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• pp.128-134
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• 2023

Centella asiatica (C. asiatica) extracts, including asiaticoside and madecassoside, are used in ointments to treat the wound and atopic dermatitis due to their antibacterial and skin-regenerating effects in Asia. Therefore, research on the cultivation and extraction efficiency of C. asiatica is being actively conducted to increase commercialization efficiency. In this study, various deep eutectic solvents (DESs) were prepared and used as the extraction solvents according to the mole ratio between the hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD). And then, the extraction yields in distilled water (DW) and methanol (MeOH), commonly used extraction solvents for C. asiatica, were compared and analyzed by HPLC in the optimized operating condition. As a result, a mixture of DW and DES at a ratio of 3:7 showed about 1.4 times higher extraction efficiency than MeOH only. Conversely, the extraction efficiency in a mixture of MeOH and DES at a ratio of 3:7 was about 6 % lower than that in MeOH only.