• Journal of Photoscience
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• 제9권2호
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• pp.305-307
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• 2002

Spectroscopic titration of D 193N and D 193E mutants of pharaonis phoborhodopsin (ppR) were performed to evaluate the pK$_{a}$ of the Schiff base Asp 193 corresponds to Glu204 of bacteriorhodopsin (bR). The pK$_{a}$ of the Schiff base (SBH$^{+}$) of D193N was 10.1~10.0 (at XH$^{+}$) and 11.4~11.6 (at X) depending on the protonation state of a certain residue (designated by X) and independent on CI$^{[-10]}$ , while those of the wild-type and D193E were> 12. pK$_{a}$ of XH$^{+}$ were; 11.8~11.2 at the state of SB, 10.5 at SBH$^{+}$ state in the presence of CI$^{[-10]}$ , and 9.6 at SBH$^{+}$ without CI$^{[-10]}$ These imply the presence of a long-range interaction in the extracellular channel.r channel.

• 공업화학
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• 제9권5호
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• pp.719-725
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• 1998

Salicylaldehyde와 2-hydroxy-1-naphthaldehyde를 2-aminophenol과 2-amino-p-cresol에 반응시켜 세자리 Schiff base 리간드들을 합성하였다. 이들 리간드를 Cu(II)이온과 반응시켜 세자리 Schiff base Cu(II) 착물들을 합성하였다. 리간드와 그 착물들의 구조와 특성을 원소분석, $^1H$-NMR, IR, UV-vis 분광법과 열 무게 분석법으로 알아보았다. Schiff base 리간드와 Cu(II)의 몰비는 1:1로 결합하며 Cu(II)착물들은 1 분자의 수화물이 배위된 4배위의 평면 사각형 구조임을 알았다. 지지전해질로서 0.1M TBAP를 포함한 DMSO 용액에서 순환 전압전류법과 미분 펄스 전압전류법으로 세자리 Schiff base 리간드와 이들의 Cu(II) 착물들의 전기 화학적인 산화 환원 과정을 알아보았다. 세자리 Schiff base 리간드들의 전기 화학적 환원은 확산 지배적이고 비가역적으로 진행되었다. Cu(II) 착물들의 전기화학적 환원과정은 1단계 1전자 반응으로 모두 확산 지배적이고 준가역적으로 진행되었다. Cu(II)착물들의 환원전위는 [Cu(II)(HNIPC)($H_2O$)]>[Cu(II)(HNIP)($H_2O$)]>[Cu(II)(SIP)($H_2O$)]>[Cu(II)(SIPC)($H_2O$)] 순으로 양전위 방향으로 이동하였다.

• 대한화학회지
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• 제13권1호
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• pp.29-36
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• 1969

lnorganic polymers, which are composed of metal (Ⅱ) ions and Schiff's Base of quinizarin-ethylenediamine, have been prepared. In order to find out proper conditions for the reaction, some investigations have been carried out to test the effect of pH, kind of solvent and the state of reagent. As a result, the highest yield occurred near pH 7 and it was found that there were not great difference in the kind of solvent and the state of reagent we had used. Most of the polymers are seemed not to be those we have attempted to prepare. They are found to be coordination polymers which have rather low molecular weight.

• 대한화학회지
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• 제39권12호
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• pp.932-939
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• 1995

시프 염기 구리(II) 착물에 의한 과산화수소 분해속도를 측정하였다. 과산화수소와 구리(II)-시프염기 착물의 반응속도는 $Cu^{II}BSDT$ 및 $Cu^{II}BSTP$인 경우 pH에 따라 증가하였으나 $Cu^{II}BSTT$의 경우 증가하였다가 감소하였다. 이 반응의 메카니즘은 과산화수소의 시프염기 구리(II) 착물의 탈양성자를 거친 다음에 속도결정단계에서 퍼옥소 구리착물이 생성되는 반응과정과 일치한다.

• Bulletin of the Korean Chemical Society
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• 제29권9호
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• pp.1774-1780
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• 2008

New PVC based polymeric membrane electrodes (PME) and coated glassy carbon electrodes (CGCE) based on synthesized Schiff base complexes of Co(III); [Co(Salen)$(PBu_3)_2$]$ClO_4$, [Co($Me_2$Salen)$(PBu_3)_2$]$ClO_4$, [Co(Salen)$(PBu_3)H_2O$]$ClO_4$; as anion carriers for potentiometric determination of $ClO_4\;^-$were studied. The PME and also CGCE electrodes prepared with [Co(Me2Salen)$(PBu_3)_2$]$ClO_4$ showed excellent response characteristics to perchlorate ions. The electrodes exhibited Nernstian responses to $ClO_4\;^-$ ions over a wide concentration range with low detection limits ($1.0 {\times} 10^{-6}\;mol\;L^{-1}$ for PME and $9.0 {\times} 10^{-7}\;mol\;L^{-1}$ for CGCE). The electrodes possess fast response time, satisfactory reproducibility, appropriate lifetime and, most importantly, good selectivity toward $ClO_4\;^-$ relative to a variety of other common inorganic anions. The potentiometric response of the electrodes is independent of the pH in the pH range 2.5-8.5. The proposed sensors were used in potentiometric determination of perchlorate ions in mineral water and urine samples. The interaction of the ionophore with perchlorate ions was shown by UV/Vis spectroscopy.

• 대한화학회지
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• 제56권4호
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• pp.440-447
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• 2012

Heteroleptic complexes of zirconium (IV) derived from bulky Schiff base ligands containing a sulphur atom and oximes of heterocyclic ${\beta}$-diketones of the general formula ZrLL' (where $LH_2=RCNH(C_6H_4)SC:C(OH)N(C_6H_5)N:CCH_3$, $R=-C_6H_5$, $-C_6H_4Cl(p)$ and $L^{\prime}H_2=R^{\prime}C:(NOH)C:C(OH)N(C_6H_5)N:CCH_3$, $R^{\prime}=-CH_2CH_3$, $-C_6H_5$, $-C_6H_4Cl(p)$ were prepared by the reactions of zirconium tetrachloride with disodium salts of Schiff bases ($L\;Na_2$) and oximes of heterocyclic ${\beta}$-diketones ($L^{\prime}\;Na_2$) in 1:1:1 molar ratio in dry refluxing THF. The structures of these monomeric zirconium (IV) complexes were elucidated with the help of elemental analysis, molecular weight measurements, spectroscopic (IR, NMR and mass) studies. A distorted trigonal bipyramidal geometry may be suggested for these heteroleptic zirconium (IV) complexes. The ligands (bulky Schiff base ligands containing a sulphur atom and oximes of heterocyclic ${\beta}$-diketones) and their heteroleptic complexes of zirconium (IV) were screened against A. flavus, P. aeruginesa and E. coli.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.850-858
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• 2010

The electronic absorption spectra of five Schiff bases derived from 2-hydroxy-1-naphthaldehyde with glycine, alanine, leucine, valine and phenylalanine have been measured in various solvents. The observed bands were assigned to the proper electronic transitions and compared with the predicted transitions at the semiempirical level of theory. The calculated equilibrium constants are in agreement with the experimental results, predicting the existence of all studied compounds predominantly or completely in keto-imine tautomerism. On the other hand, a correlation between $\nu\;(cm^{-1})$ (main frequency of each compound) and the well known solvent parameters $E_T$ (30), $\varepsilon_T$, $\pi^*$ been made. Furthermore, the acid dissociation constants, $pK_a$, were determined by using three different spectrophotometric methods.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2326-2330
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• 2014

A carbazole-based Schiff base CB2 was synthesized and applied as a highly selective and sensitive fluorescent probe for $Cu^{2+}$ in $H_2O$-DMSO (8/2, v/v, pH = 7.4) solution. CB2 exhibits an excellent selectivity to $Cu^{2+}$ over other examined metal ions with a prominent fluorescence "turn-on" at 475 nm. CB2 and $Cu^{2+}$ forms a 1:2 binding ratio complex with detection limit of $9.5{\mu}M$. In addition, the $Cu^{2+}$ recognition process is hardly interfered by other examined metal ions.

• Bulletin of the Korean Chemical Society
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• 제25권7호
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• pp.986-990
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• 2004

Condensation of salicylaldehyde $(2-HOC_6H_4C(O)H)$ with allylamine afforded the unsaturated salicylaldimine, $2-HOC_6H_4C(H)=NCH_2CH=CH_2$. Similar reactivity was observed with substituted salicylaldehydes. Further reaction of these Schiff bases with palladium acetate or $Na_2PdCl_4$ afforded complexes of the type $PdL_2$, where L = deprotonated Schiff base. The molecular structure of the parent salicylaldimine palladium complex $[trans-(2-OC_6H_4C(H)=NCH_2CH=CH_2)_2Pd]$ (1) was characterized by an X-ray diffraction study. Crystals of 1 were monoclinic, space group $P2_1/n,\;a\;=\;14.0005(9)\;{\AA},\;b\;=7.2964(5)\;{\AA},\;c\;=\;17.5103(12)\;{\AA},\;{\beta}\;=\;100.189(1)^{\circ}$, Z = 4. Analogous chemistry with 4-vinylaniline also gave novel palladium complexes containing a pendant styryl group. Crystals of $[trans-(2-HOC_6H_4C(H)=N-4-C_6H_4CH=CH_2)_2Pd]$ (4) were monoclinic, space group $P2_1/c$, a = 13.7710(14) ${\AA}$, b = 11.0348(11) ${\AA}$, c = 7.8192(8) ${\AA}$, ${\beta}\;=\;98.817(2)^{\circ}$, Z = 2.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1699-1703
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• 2010

The Schiff base N,N'-bis(pyridin-2-ylmethylene)benzene-1,2-diamine [BPBD] has been synthesized and explored as ionophore for preparing PVC-based membrane sensors selective to the silver ($Ag^+$) ion. Potentiometric investigations indicate high affinity of this receptor for silver ion. The best performance was shown by the membrane of composition (w/w) of ionophore: 1 mg, PVC: 33 mg, o-NPOE: 66 mg and additive were added 50 mol % relative to the ionophore in 1 mL THF. The sensor works well over a wide concentration range $1{\times}10^{-3}$ to $1.0{\times}10^{-7}$ M by pH 6 at room temperature (slope 58.6 mV/dec.) with a response time of 10 seconds and showed good selectivity to silver ion over a number of cations. It could be used successfully for the determination of silver ion content in environmental and waste water samples.