• Korean Chemical Engineering Research
• /
• 제45권5호
• /
• pp.487-492
• /
• 2007

본 연구에서는 $G_2$[naphthalene disulfonate] 숙주 분자(host molecule)의 선택적 내포현상을 이용하여 구조적 이성질체인 1,2-dibromobenzene과 1,3-dibromobenzene을 분리하였다. 혼합 이성질체 용액에서 $X_{1,3-DBB}=0.3$ 이상 일 때, 숙주 분자는 1,3-dibromobenzene 손님 분자(guest molecule)에 대해 내포 선택도가 높았으나, $X_{1,3-DBB}=0.2$ 이하의 용액에서는 1,2-dibromobenzene 손님 분자에 대한 내포 선택도가 높았다. 이것은 용액의 조성에 따라 특정 이성질체가 숙주 분자 구조의 주형 역할을 하여 해당 분자에 대한 손님 분자로서의 내포 선택도를 결정하기 때문이다. 이러한 숙주 분자 구조에 대한 손님 분자의 주형 역할은 순수 이성질체 용액 및 혼합 이성질체 용액에서 생성된 내포 화합물의 X-ray 회절 분석 결과로부터 확인할 수 있었다. 한편, 열시차분석(DSC)에서 (1,3-dibromobenzene)-내포 화합물이(1,2-dibromobenzene)-내포 화합물 보다 안정하여 손님 분자를 숙주 분자로부터 유리시키는 더 많은 에너지를 요구하였다. 이러한 열적 안정성은 $G_2$[naphthalene disulfonate] 숙주 분자가 더 넓은 농도 범위에서 1,3- dibromobenzene에 대해 선택도를 갖는 것과 부합하는 결과이다. 본 연구에서는 숙주 분자의 선택도와 내포 화합물의 열적 안정성과의 관련성을 도출해 냈으며, 열적 안정도 평가가 숙주분자의 선택적 내포 현상을 예측할 수 있는 수단으로 적용될 가능성을 확인할 수 있었다.

• 대한화학회지
• /
• 제40권7호
• /
• pp.509-514
• /
• 1996

3차원 금속착체 포접화합물 $Cd(pn)Ni(CN)_4{\cdot}0.5NO_2C_6H_5$(pn: 1,2-diaminopropane=propylenediamine)은 사방정계 공간군 $Pn2_1$a로, a=13.868(5), b=26.591(4), c=7.840(1)${\AA}$, V=2891(1)${\AA}^3$, Z=4이며, 28000개의 독립적인 회절반점에 대한 R값은 0.054이다. 이 포접화합물의 host구조는 가지 달린 지방족 guest 분자를 포접한 포접화합물의 host 구조(T-type)와 같다. Nitrobenzene guest 분자는 T-type의 nodal형 턴넬속에 안정하게 포접되는데, 이는 node 위치체 pn-amino group이 놓이고, antinode 위치에 부피가 큰 방향조 고리가 놓이며, 이들 사이에 극성인 nitro group이 있기 때문이다. 턴넬형의 포접골간을 갖는 금속착체 $Cd(pn)Ni(CN)_4$의 host 구조가 가지 달린 방향족 guest 분자를 포접하고 있다.

• Bulletin of the Korean Chemical Society
• /
• 제22권11호
• /
• pp.1248-1254
• /
• 2001

The conformations and energies of p-tert-butylcalix[4]crown-6-ether (1) and its alkyl ammonium complexes have been calculated by ab initio HF/6-31G quantum mechanics method. The cone conformation was found to be most stable for free host 1. We hav e determined the binding site of these host-guest complexes focusing on the crown-6-ether or p-tert-butylcalix[4]arene pocket of the cone conformation of host molecule 1. The primary binding site of host 1 for the recognition of alkyl ammonium guests was confirmed to be the central part of the crown moiety of cone conformation. The complexation energy calculations revealed that the ammonium cation without alkyl group showed the highest complexation efficiency when combined with host 1, that is in satisfactory agreement with the experimental results.

• 대한화장품학회지
• /
• 제15권1호
• /
• pp.51-62
• /
• 1989

Inclusion complex formation of octyldimethl p-aminobenzoate with $\beta$-cyclodextrin in aqueous solution and in the solid state was studied by the solubility method, spectroscopic(UV, FT-lR) and X -ray diffractometry. The solid complex of octyldimethy p-aminobenzoate with $\beta$-cyclodextrin was obtained in molar ratio of 1 : 2(guest/host). A spatial relationship between host and guest molecule was clearly reflected in the magnitude of the apparent stability constant (K') and in the stoichiometry of the inclusion complex. Furthermore, a typical type Bs phase-solubility diagram was obtained for octyldimethyl p-aminobenzoate and p -cyclodextrin in water at $25^{\circ}C$. The results indicated that the solubility of the guest molecule was higher by the formation of $\beta$-cyclodextrin inclusion complex.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
• /
• pp.150.2-150.2
• /
• 2011

Unlike non-ionic clathrate hydrates stably formed by van der Waals interaction between a guest molecule and a surrounding host framework, ionic clathrate hydrates are stabilized by ionic interaction between an ionic guest molecule and the host water-framework. Here, we firstly described the stable entrapment of the superoxide ions in ${\gamma}$-irradiated $Me_4NOH+O_2$ hydrate. Owing to peculiar direct guest-guest ionic interaction, the lattice structure of ${\gamma}$-irradiated $Me_4NOH+O_2$ hydrate shows significant change of lattice contraction behavior even at relatively high temperature(120K). Particularly, we note that ionic-induced dimensional change is much greater than thermal-induced change. Such findings are expected to provide useful information for a better understanding of unrevealed nature of clathrate hydrate fields.

• 한국응용과학기술학회지
• /
• 제6권1호
• /
• pp.59-66
• /
• 1989

Inclusion complex formation of octyldimethyl p-aminobenzoate with ${\beta}-cyclodextrin$in aqueous solution and in the solid state was studied by the solubility method, spectroscopic (UV, FT-IR) and X-ray diffractornetry. The solid complex of octyldimethyl p-aminobenzoate with ${\beta}-cyclodextrin$ was obtained in molar ratio of 1:2 (guest/host). A spatial relationship between host and guest molecule was clearly reflected in the magnitude of the apparent stability constant (K') and in the stoichiometry of the inclusion complex. Furthermore, a typical type Bs phase-solubility diagram was obtained for octyldimethyl p-aminobenzoate and ${\beta}-cyclodextrin$ in water at $25^{\circ}C$. The results indicated that the solubility of the guest molecule was higher by the formation of ${\beta}-cyclodextrin$ inclusion complex.

• Bulletin of the Korean Chemical Society
• /
• 제18권5호
• /
• pp.473-474
• /
• 1997

• Journal of Periodontal and Implant Science
• /
• 제26권3호
• /
• pp.655-668
• /
• 1996

The change in vascular adhesion molecule expression and number of infiltrating leukocytes were investigated irnmunohistochemically in clinically healthy and inflammed gingiva. Monoclonal antibodies to ICAM-1, VCAM-1 and E-cadherin were used to identify positive vessels and leukocyte within gingival biopsies. 10 healthy gingiva and 30 inflammed gingiva was resected by clinical crown lengthening and modified Widman flap operation, respectively. Leukocyte entry into tissues at sites of inflammation is controlled by the interaction between adhesion molecule and endothelium. Because of rapid and severe destructive periodontal disease that is remarkable leukocyte adhesion deficiency, it is very important to unerdstand the mechanism of host defence against periodontal disease. The purpose of this investigation was the characterization of the presence and distribution of the adhesion molecule(ICAM-1, VCAM-1 and Evcadherin) in inflammatory gingival tissues compared to clinically healthy gingiva. The results were as followed; 1. ICAM-1 was distributed on basal layer, endothelium and mononuclear cells 10 healthy gingiva but inflammed gingiva was observed stronger stain than healthy gingiva. 2. Rare expression was observed in both group but few positive VCAM-1 cells were investigated in inflammatory gingival tissues 3. E-cadherin was expressed in only epithelium and reduced expression was observed in inflammatory gingival tissues. ICAM-1, VCAM-1 showed more expression in inflammatory tissues compared to healthy gingiva. Conversely, E-cadherin revealed a opposite result. These finding demonstrate a characteristic distribution and degree of adhesion molecule in healthy and inflammatory gingival tissues. But it is suggested that more detail study be progressive associated with leukocyte adhesion molecule to determine characterization of periodontal disease.

• Mass Spectrometry Letters
• /
• 제6권1호
• /
• pp.17-20
• /
• 2015

Sesamin, one of the lignans in sesame seed, was a labile compound in MS and it was reported that the protonated molecule of sesamin decomposed easily in ES ionization process and it cannot be detected (G. Yan, et al., Rapid Commun Mass Spectrom. 2007, 21, 3613-3620). To protect labile compounds, an amino-cyclodextrin (NCyD) was added to the sample to promote the host-guest interaction complex in ESI-MS. As a result, sesamin was ionized as the NCyD-sesamin-NCyD (1:2) complex without undesired decomposition, suggesting that the amino-CyDs assist the ionization of the labile molecules capped with CyDs by host-guest interaction and these compounds were ionized without their decomposition, those are like amino-CyD complex-assisted ionization. The amino-CyD complexes of sesamin and sesamolin were also analyzed by their ion-mobility MS.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.767-770
• /
• 2009

We synthesized a spirobenzofluorene type phosphine oxide (SPPO2) as a new triplet host and an universal electron transport material for phosphorescent organic light-emitting diodes(PHOLEDs). Red PHOLEDs with the SPPO2 host material showed a high quantum efficiency of 14.3 % with a current efficiency of 20.4 cd/A. In addition, the SPPO2 could be applied as an electron transport material which can be matched with any host material due to the lowest unoccupied molecular orbital of 2.4 eV. Electron injection from a cathode to the SPPO2 electron transport layer was better than common electron transport materials. In particular, the SPPO2 was effective as the electron transport material in blue PHOLEDs and the quantum efficiency was more than doubled and driving voltage was lowered by more than 3 V using the SPPO2 instead of common electron transport material.