• Textile Coloration and Finishing
• /
• v.21 no.5
• /
• pp.51-57
• /
• 2009

Since heavy metal pollution is a significant global environmental problem and very dangerous to human health, the improved methods for detecting heavy metals are required recently. Colorimetric chemosensors are now considered as one of the most effective analytical method used in the environment monitoring. New direct dyes having the function of colorimetric chemosensors were synthesized. When metal ions such as $Al^{3+}$, $Ca^{2+}$, $Cd^{2+}$, $Cr^{3+}$, $Cu^{2+}$, $Fe^{2+}$, $Fe^{3+}$, $Hg^{2+}$, $Li^+$, $Mg^{2+}$, $Na^+$, $Ni^{2+}$, $Pb^{2+}$ and $Zn^{2+}$ were added each solution of new direct dyes, the color of solution was changed and can be easily detected with naked eyes without expensive experimental equipment such as atomic absorption spectrometer (AAS) or inductively coupled plasma?mass spectrometer (ICP-MS). The new benzidine analogues were diazotized and reacted with couplers such as H-acid, J-acid, Chromotropic acid, Nevill-winther acid and gamma acid to synthesize new direct dyes. The structures of the new direct dyes were confirmed by high resolution mass spectrometer (FAB ionization) and evaluated with UV-Vis spectroscopy. The UV-VIS spectroscopy was measured for the dye solutions by adding various concentrations of metal ions. It was observed that the absorbance in UV-Vis spectra was changed as the heavy metal ions were added.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.8
• /
• pp.2523-2528
• /
• 2014

In the present study, at first, azo Schiff base ligand of (N,N'-bis(5-phenylazosalicylaldehyde)-ethylenediamine) ($H_2L$) has been synthesized by condensation reaction of 5-phenylazosalicylaldehyde and ethylenediamine in 2:1 molar ratio, respectively. Then, its cobalt complex (CoL) was synthesized by reaction of $Co(OAc)_2{\cdot}4H_2O$ with ligand ($H_2L$) in 1:1 molar ratio in ethanol solvent. This ligand and its cobalt complex containing azo functional groups were characterized using elemental analysis, $^1H$-NMR, UV-vis and IR spectroscopies. Subsequently, the interaction between native calf thymus deoxyribonucleic acid (ct-DNA) and CoL complex was investigated in 10 mM Tris/HCl buffer solution, pH = 7 using UV-vis absorption, thermal denaturation technique and viscosity measurements. From spectrophotometric titration experiments, the binding constant of CoL complex with ct-DNA was found to be $(2.4{\pm}0.2){\times}10^4M^{-1}$. The thermodynamic parameters were calculated by van't Hoff equation.The enthalpy and entropy changes were $5753.94{\pm}172.66kcal/mol$ and $43.93{\pm}1.18cal/mol{\cdot}K$ at $25^{\circ}C$, respectively. Thermal denaturation experiments represent the increasing of melting temperature of ct-DNA (about $0.93^{\circ}C$) due to binding of CoL complex. The results indicate that the process is entropy-driven and suggest that hydrophobic interactions are the main driving force for the complex formation.

• Applied Chemistry for Engineering
• /
• v.24 no.1
• /
• pp.93-98
• /
• 2013

In this paper, four conducting polymers (poly[(N-butyl-phenothiazine)-sulfide] (PBPS), poly[(N-hexyl-phenothiazine)-sulfide] (PHPS), poly[(N-decyl-phenothiazine)-sulfide] (PDPS), and poly[(N-(2-ethylhexyl)-phenothiazine)-sulfide] (PEHPS)) were synthesized with a high temperature and high pressure reaction. The structures of synthesized polymers were confirmed by $^1H-NMR$ and characterized by UV-Vis, cyclic voltammetry, and GPC. From the UV-Vis absorption spectra, the ${\lambda}_{max}$ values of PBPS, PHPS, PDPS, and PEHPS were 338, 341, 340, and 334 nm, respectively and their optical band gaps were 3.11, 3.13, 3.16, and 3.05 eV, respectively. To evaluate the feasible applicability as a photovoltaic cell, the devices composed of for example, ITO/PEDOT : PSS/polymer (PBPS, PDPS) : $PC_{71}BM$ (1 : 3, w/w)/$BaF_2$/Ba/Al were fabricated using the blends of the PBPS and PDPS as a donor, and $PC_{71}BM$ as an acceptor. Then, the power conversion efficiencies (PCE) of devices were estimated as 0.076% of PBPS and 0.136% of PDPS by solar simulator.

• The Journal of the Petrological Society of Korea
• /
• v.22 no.1
• /
• pp.1-8
• /
• 2013

Physical properties, XRF, UV-Vis, FTIR studies were carried out in order to characterize gemological features of ruby from Tajikistan. Fluorescence reaction of the Tajikistan ruby to short wave ultraviolet was moderate to very strong in red and long wave ultraviolet rays was weakly detected. UV-visible analysis strong absorption bands at 468.5, 475, 476.5 nm and broaden bands at 550 nm were observed for ruby due to $Cr^{3+}$. According to FT-IR analysis, all rubies from Tajikistan showed the similar patterns and kaolinite peaks at 3500, 3617, 3630, $3677cm^{-1}$ and boehmite broaden absorption bands at 3085 and $3320cm^{-1}$. Inclusions in Tajikistan ruby are observed solid inclusions, negative crystals, needle and silk inclusions. These distinctive characteristics mentioned above can be used to identify the locality and source of ruby stones from Tajikistan.

• Polymer(Korea)
• /
• v.30 no.5
• /
• pp.417-421
• /
• 2006

Photo -alignment of poly (siloxane cinnamate) (PSCN) was studied to better understand the alignment mechanism of cynnamoyl groups under various process conditions. DSC and polarized microscope studies showed that the isotropic temperature oi PSCN was about $105^{\circ}C$ and the liquid crystallinity, once formed, did not completely disappear even when the temperature went into the isotropic regions. UV/Vis absorption study suggested that the photo - dimerization was the main photo alignment mechanism and it's efficiency could be enhanced through the self-alignment of PSCN. It was also found that photo-dimerization was in competition with photo-fries reaction and the photo- alignment of PSCN was interfered with the excessive UV because of the strong photo-fries reaction. However, photo - fries reaction could be suppressed by adjusting the UV wavelength.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.9
• /
• pp.1208-1254
• /
• 2002

Photoreaction of N-(o-halophenyl)acetamide in basic acetonitrile produces an intramolecular substituted product, 2-methylbenzoxazole in addition to reduced product, acetanilide, whereas photoreaction of N-(o-halobenzyl) acetamide affords a reduced product, N-benzylacetamide only. On the basis of preparative reaction, kinetics, and UV/vis absorption behavior, an electrophilic aromatic substitution of aryl halide with oxygen of its amide bond are proposed.

• Journal of the Korean Applied Science and Technology
• /
• v.14 no.2
• /
• pp.65-70
• /
• 1997

The symmetric naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. The stability on the solvents of naphthothiazolo carbocyanine dye was measured by UV-Vis spectrophotometer, and then all of solvents were stabilized sensitizer. The maximum absorption peak range in various solvents was $600nm{\sim}612nm$. But it was identified that only methanol can be used to photographic emulsion.

• Journal of Photoscience
• /
• v.5 no.1
• /
• pp.45-46
• /
• 1998

The green-sensitive silver halide emulsion layer has been studied UV-Vis absorption band of 9-methvl-5,5'-diphenyl-3,3'-bis(3-sulfopropyl)benzoxazolo carbocyanine triethyl ammonium salt in methanol solution and 10% methanol containing 10$^{-2}$ M KCl. the products were observed at 502nm and 540nm(J-band), respectively. The maximum spectral sensitivity of sensntizing silver halide emulsion showed at 546nm. In conclusion, benzoxazolo carbocyanine dye can be used as a green-sensitizing dye for the photographic emulsion.

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.02a
• /
• pp.210-211
• /
• 2003

대기 환경에 있어서 인간에 위해한 기준 가스들을 측정하는 방법은 여러 가지가 있다. 근래에 이르러 이들을 측정 관리하기 위하여 분광학적인 방법을 이용하는 시도가 늘어나고 있다. 유럽에서 널리 이용중인 차등 흡수 분광기(Differential Optical Absorption Spectrometer)는 현재는 위성에 응용되어 운용되고 있으며 가스의 전자 떨림이나 회전에 의한 에너지 흡수선을 이용하여 해당가스를 검출해내는 기술을 그 원리로 하고 있다. (중략)

• Journal of Integrative Natural Science
• /
• v.2 no.3
• /
• pp.215-218
• /
• 2009

A silaspirotropylidene has been obtained from the reaction of the lithium salt of tetraphenylsilole dianion with 2 equiv of diphenylcyclopropene, followed by quenching with Me3SiCl. Silaspirotropylidene exhibits an unusual optical property its optical property was characterized by UV-vis and fluorescence spectroscopy. Absorption wavelength maxima of silaspirotropylidene was 420 nm. silaspirotropylidene displayed an emission band at 550 nm with excitation wavelength of 420 nm.