• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.4075-4078
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• 2011

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.979-982
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• 2013

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1533-1536
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• 2013

• Mass Spectrometry Letters
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• v.6 no.1
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• pp.1-6
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• 2015

Direct analysis in real time mass spectrometry (DART-MS) is one of the variants of ambient mass spectrometry. The ionization process of DART-MS is in open environment and only takes few seconds, so it is suitable for fast analysis. Actually, since its introduction in 2005, more and more attentions have been drawn to its various applications due to its excellent properties, e.g., fast analysis, and no or less sample preparation, high salt tolerance and so on. This review summarized the promising features of DART-MS, including its ionization mechanism, equipment modification, wide applications, coupling techniques and extraction strategies before analysis.

• International Journal of Advanced Culture Technology
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• v.10 no.1
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• pp.170-179
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• 2022

To find out the effect of interest on chemical content, interest in chemistry, choice of science elective subjects, teaching-learning characteristics that make it difficult to understand contents, academic achievement in general chemistry according to university admission screening, etc. were surveyed on 51 students enrolled in the department of chemistry education at P college of education. As a result of the survey, it was found that the interest in Chemistry I, Chemistry II, and general chemistry increased significantly to 94.6%, 73.7%, and 66.0%, respectively. 39.3% of the students answered that they had a lot of difficulty in understanding general chemistry. The characteristics of learners who make it difficult to understand the content were found to be 'lack of willingness to learn' such as 'lack of understanding chemical concepts' and 'lack of problem solving', due to the lack of 'basic knowledge'. As a way to solve these difficulties, 'expert help' appeared the most. The grades of general chemistry of students who entered the regular admission were relatively higher than those of occasional recruitment.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1150-1154
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• 2003

The reactions of [Ni(L)(H₂O)₂]Cl₂ (L = 2,5,9,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane) with terephtalate (tp) and 2,5-pyridinedicarboxylate (pdc) generate one-dimensional nickel(II) complexes, [Ni(L)(H₂O)₂](tp) · ₄H₂O (1) and [Ni(L)(H₂O)₂](pdc)·₄H₂O (2). The structures have been characterized by X-ray crystallography, magnetic susceptibility and spectroscopy. The crystal structures of 1 and 2 show a distorted octahedral coordination geometry around the Ni(II) ion, with secondary amines of the macrocycle and two water molecules at the trans position. Complexes 1 and 2 display the one-dimensional hydrogen-bonded infinite chains. The magnetic behavior of all compounds exhibits weak interchain antiferromagnetic interactions with J values of -1.09(3) for 1 and -1.14(2) cm-1 for 2.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2779-2781
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• 2009

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1865-1868
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• 2006

• Bulletin of the Korean Chemical Society
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• v.12 no.6
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• pp.591-592
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• 1991

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3279-3282
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• 2010

The reaction rates of 4-X-2,6-dinitrochlorobenzenes (X = $NO_2$, CN, $CF_3$) with Y-substituted benzylamines (Y = p-$OCH_3$, p-$CH_3$, H, p-Cl) in MeOH-MeCN mixtures were measured by conductometry at $25^{\circ}C$. It was observed that the rate constant increased in the order of X = $NO_2$ > CN > $CF_3$ and in the order of Y = p-$OCH_3$ > p-$CH_3$ > H > p-Cl. When the solvent composition was varied, the rate constant increased in the order of 100% MeOH < 50% (v/v) MeOH-MeCN < 100% MeCN. These results may be ascribed to the formation of hydrogen bonds between the alcoholic hydrogen and nitrogen of benzylamines in groud state (GS). We conclude that the reaction takes place via $S_NAr$ base on the transition state parameters ${\rho}x$, ${\rho}Y$, $\beta_{nuc}$, and solvent effects.