• 대한화학회지
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• 제38권4호
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• pp.302-308
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• 1994

산소가 포화된 메탄올 용액에서 다섯자리 Schiff base cobalt(II) 착물인 [Co(II)(Sal-DPT)(H$_2$O)] 와 [Co(II)(Sal-DET)(H$_2$O)]들의 활성촉매에 의한 hydrazobenzene(H$_2$AB)의 산화 주생성물은 trans-azobenzene(trans-AB)이다. UV-visible분광광도법에 의해 이들 반응의 속도상수 $k=6.06{\times}10^{-3}sec^{-3}$ 및 $2.50{\times}10^{-3}sec^{-1}$로 주어짐을 알았다. 균일 산화 활성촉매에 의한 H$_2$AB의 산화반응 메카니즘은 다음과 같은 과정으로 주어진다. H$_2$AB + Co(II)(L)(H$_2$O) + O$_2$ $\rightleftharpoons^K_{methanol}Co(III)(L)O_2{\cdot}H_2AB + H_2O\longrightarrow^{k}Co(II)(L) + trans-AB + H_2O_2$ (L: Sal-DPT and Sal-DET).

• 분석과학
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• 제11권6호
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• pp.440-447
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• 1998

브롬 치환기를 가지는 여러자리 시프염기인 5-Br-BSDT(bis(5-bromosalicylaldehyde)diethy- lenetriamine), 5-Br-BSTT(bis(5-bromosalicylaldehyde)triethylenetetramine)와 5-Br-BSTP(bis(5-bromosalicylaldehyde)tetraethylenepentamine)를 합성하여 DMSO 용매에서 이들 리간드들과 구리(II), 니켈(II) 및 아연(II) 등의 전이금속과의 안정도 상수값을 폴라로그래피를 이용하여 구하였다. 이때 금속과 리간드는 1 : 1착물을 형성하였고, 안정도 상수값은 금속으로서는 Cu(II)>Ni(II)>Zn(II) 순서로, 리간드로서는 5-Br-BSTP>5-Br-BSTT>5-Br-BSDT 순서로 나타남으로서 주개 원자수의 증가에 의존한다는 사실을 알았다. 엔탈피와 엔트로피는 모두 음의 값을 나타내었는데 흡열반응으로서 금속이온과 리간드가 매우 강하게 결합하고 있음을 알 수 있고 극성을 가지는 금속착물이 생성되어 용매인 DMSO와 아주 강한 상호작용을 함으로써 큰 음의 엔트로피 값을 가진 것으로 생각된다.

• 공업화학
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• 제7권3호
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• pp.416-423
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• 1996

Co(II), Ni(II), Cu(II) 및 Mn(II)의 네자리 Schiff base 전이금속 화합물들이 첨가된 1.5 M $LiAlCl_4/SOCl_2$ 전해질 용액에서 $SOCl_2$에 관한 전기 화학적 환원 반응을 조사하였다. 이들 전이 금속(II) 착물들은 먼저 전극 표면에 흡착된 후 촉매로써 작용하였으며, 각각의 전이 금속(II) 착물들의 촉매 화합물에 대해 $SOCl_2$를 환원시킬 수 있는 최적 조건의 농도를 나타냈다. 촉매가 첨가된 전해질 용액에서 $SOCl_2$의 환원 반응에 대한 환원 전류는 최고 150% 정도 증가하였다. 주사 속도가 증가함에 따라 $SOCl_2$의 환원 전류는 증가하였고 환원 전위는 음 전위 방향으로 이동되었으며, $SOCl_2$의 환원 과정은 확산 지배적인 반응으로 진행되었다.

• 대한화학회지
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• 제37권8호
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• pp.702-710
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• 1993

이핵성 네자리 schiff base Co(II), Ni(II), Cu(II) alc Fe(II) 착물들을 촉매로 사용하여 몰리브데늄 전극과 유리질 탄소 전극에서 SOCl2의 전기화학적 환원반응을 조사하였다. 이들 전이금속(II) 착물들은 먼저 전극 표면에 흡착된 후 촉매로 작용하였으며, 각각의 전이금속(II) 착물들의 촉매 화합물은 SOCl$_2$ 를 환원시킬 수 있는 최적 조건의 농도를 나타냈다. SOCl$_2$의 환원반응에 대한 촉매 효과는 몰리브데늄 전극에서보다 유리질 탄소전극에서 더 크게 나타났고, 환원 전류는 최고 120% 정도 증가하였다. 주사속도 증가에 따른 SOCl$_2$의 환원 전류는 증가하였고 환원 전위는 음전위쪽으로 이동되었으며, SOCl$_2$의 환원과정은 확산지배적인 반응으로 진행되었다.

• 폴리머
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• 제39권2호
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• pp.225-234
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• 2015

In this study, we proposed to synthesize thermally stable, soluble and conjugated Schiff base polymer (SbP). For this reason, a specific molecule namely 4,4'-thiodiphenol which has sulfur and oxygen bridge in its structure was used to synthesize bi-functional monomers. Bi-functional amino and carbonyl monomers namely 4,4'-[thio-bis(4,1-phenyleneoxy)] dianiline (DIA) and 4,4'-[thiobis(4,1-phenyleneoxy)]dibenzaldehyde (DIB) were prepared from the elimination reaction of 4,4'-thiodiphenol with 4-iodonitrobenzene and 4-iodobenzaldehyde, respectively. The structures of products were confirmed by elemental analysis, FTIR, $^1H$ NMR and $^{13}C$ NMR techniques. The molecular weight distribution parameters of SbP were determined by size exclusion chromatography (SEC). The synthesized SbP was characterized by solubility tests, TG-DTA and DSC. Also, conductivity values of SbP and SbP-iodine complex were determined from their solid conductivity measurements. The conductivity measurements of doped and undoped SbP were carried out by Keithley 2400 electrometer at room temperature and atmospheric pressure, which were calculated via four-point probe technique. When iodine was used as a doping agent, the conductivity of SbP was observed to be increased. Optical band gap ($E_g$) of SbP was also calculated by using UV-Vis spectroscopy. It should be stressed that SbP was a semiconductor which had a potential in electronic and optoelectronic applications, with fairly low band gap. SbP was found to be thermally stable up to $300^{\circ}C$. The char of SbP was observed 29.86% at $1000^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• 제26권6호
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• pp.892-898
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• 2005

A long, bis(monodentate), linking Schiff-base ligand L (py-CH=N-$C_6H_4$-N=CH-py) was prepared from 1,4-phenylenediamine and 3-pyridinecarboxaldehyde by the Schiff-base condensation. Ligand L has two terminal pyridyl groups capable of coordinating to metals through their nitrogen atoms. In contrast, the same reaction between 1,2-phenylenediamine and 3-pyridinecarboxaldehyde produced a mixture of imidazol isomers (2-pyridin-3-yl-1H-benzoimidazole), which are connected to one another by the N-H…N hydrogen bonding to form a tetramer. From Zn($NO_3)_2{\cdot}6H_2O$ and ligand L under various conditions, one discrete molecule, trans- [Zn($H_2O)_4L_2]{\cdot}(NO_3)_2{\cdot}(MeOH)_2$, and two 1-D zinc polymers, [Zn$(NO_3)(H_2O)_2(L)]{\cdot}(NO_3){\cdot}(H_2O)_2$ and [Zn(L) (OBC)($H_2O$)], were prepared. In ligand L, the N$\ldots$N separation between the terminal pyridyl groups is 13.994 $\AA$, with their nitrogen atoms at the meta positions (3,3’) in a trans manner. The corresponding N$\ldots$N separations in its compounds range from 13.853 to 14.754 $\AA$.

• 대한화학회지
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• 제54권1호
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• pp.23-26
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• 2010

Schiff 리간드인 (Z)-N-((Z)-2-(sec-butylimino)-1,2-diphenylethylidene)butan-2-amine을 벤질과 sec-부틸아민과의 축합반응에 의해 합성하였다. 일 주기 전이금속인 망간(II) 및 니켈(II)과 리간드와의 착물반응을 시도하였다. 리간드 및 착물의 특성을 FTIR, 원소분석 및 열무게분석으로 고체 상태에서, 그리고 NMR ($^1H,\;^{13}C$)로 용액 상태에서의 각각 조사하였다. 두 착물 모두 온화한 조건에서 methylaluminoxane (MAO) 존재 하에 부타디엔 올리고화 반응의 조촉매로 좋은 촉매활성을 보였다.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3361-3367
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• 2012

Two novel Eu(III) complexes with notable properties have been successfully prepared with hydrazone Schiff base ligands, (E)-2-hydroxy-N'-[(2-hydroxynaphthalen-1-yl)methylene]benzohydrazide (3a) and (E)-4-hydroxy-N'-[(2-hydroxynaphthalen-1-yl)methylene]benzohydrazide (3b). DFT, FMO energy and Mulliken charge distribution studies of the ligands allowed us to hypothesize that their HC=N, > C=O and -OH (naphthyl) groups were involved in coordinating with the $Eu^{3+}$ ion. The eight coordination sites of the $Eu^{3+}$ ion were occupied by the three functional groups of the two ligands (3a or 3b) mentioned above and two water molecules. Similar UV, IR and fluorescence spectra indicated the presence of comparable coordination environments for the $Eu^{3+}$ ion in both complexes. Both the ligands and their complexes exhibited moderate DPPH radical scavenging activity. Moreover, it was found that the Eu(III) complexes exhibited fluorescence properties.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.401-405
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• 2010

The Schiff base 1,2-bis(E-2-hydroxy benzylidene amino)anthracene-9,10-dione has been synthesized and explored as ionophore for preparing PVC-based membrane sensors selective to the copper ($Cu^{2+}$) ion. Potentiometric investigations indicate high affinity of these receptors for copper ion. The best performance was shown by the membrane of composition (w/w) of ionophore: 1 mg, PVC: 33 mg, DOP: 66 mg and KTpClPB as additive were added 50 mol % relative to the ionophore in 1 ml THF. The proposed sensor's detection limit is $2.8{\times}10^{-7}$ M over pH 5 at room temperature (Nernstian slope 31.76 mV/dec.) with a response time of 15 seconds and showed good selectivity to copper ion over a number of interfering cations.

• Journal of Electrochemical Science and Technology
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• 제8권3호
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• pp.222-235
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• 2017

First, in this study, the inhibition efficiencies of metal complexes with Cu(II), Ni(II) and Zn(II) of STSC ligand for corrosion control of mild steel in oilfield formation water were investigated. The IEs for a mixture of 500 ppm STSC and 5 ppm metal ion ($Cu^{+2}$, $Ni^{+2}$, $Zn^{+2}$) were found to be 88.77, 87.96 and 85.13 %, respectively. The results were obtained from the electrochemical techniques such as open circuit potential, linear and tafel polarization methods. The polarization studies have showed that all used Schiff base metal complexes are anodic inhibitors. The protective film has been analyzed by FTIR technique. Also, to detect the presence of the iron-inhibitor complex, UV-Visible spectral analysis technique was used. The inhibitive effect was attributed to the formation of insoluble complex adsorbed on the mild steel surface and the adsorption process follows Langmuir adsorption isotherm. The surface morphology has been analyzed by SEM. Secondly, the computational studies of the ligand and its metal complexes were performed using DFT (B3LYP) method with the $6-311G^{{\ast}{\ast}}$ basis set. Finally, it is found that the experimental results were closely related to theoretical ones.