• Macromolecular Research
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• v.15 no.7
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• pp.633-639
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• 2007

A variety of NMR techniques were applied to the micro-chemical structural characterization of polyanilines prepared via an efficient synthetic method in a self-stabilized dispersion medium in which the polymerization was conducted in a heterogeneous organic/aqueous biphasic system without any stabilizers. Here, the monomer and growing polymer chain were shown to function simultaneously as a stabilizer, imparting compatibility for the dispersion of the organic phase, and as a form of flexible template in an aqueous reaction medium. Polymerizations predicated on this concept generated polyanilines with a low defect content: solution state $^{13}C-NMR$ and solid $^{13}CDD/CP/MAS$ spectroscopy indicated that the synthesized HCPANi and its soluble derivative, HCPANi-t-BOC, evidenced distinctly different NMR spectra with fewer side peaks, as compared to conventionally prepared PANis, and the complete structural assignments of the observed NMR peaks could be determined via the combination of both 1D and 2D techniques. Ortho-linked defects in HCPANi were estimated to be as low as 7%, as shown by a comparison of the integration of the carbonyl carbon resonance peaks.

• Journal of Integrative Natural Science
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• v.2 no.1
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• pp.50-53
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• 2009

New functionalized siloles have been synthesized and their optical characterizations are investigated. Silole unit has been interested, since silole has a unique optical and electronic properties. Here we report the synthesis of new type of photoluminescent silole. New siloles have been characterized by NMR, FTIR, and UV-vis absorption spectroscopy. Their optical characteristics have been also investigated using photoluminescence spectroscopy. Possible applications such as OLED and chemical sensors will be presented.

• Bulletin of the Korean Chemical Society
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• v.16 no.11
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• pp.1079-1084
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• 1995

New cyclophanes having multilactam linkages were synthesized and characterized. One-pot coupling reaction of 2,6-pyridinedicarbonyl dichloride and a diamine gave a tetralactam, a hexalactam, and a octalactam in good yields. The TLC behaviour, the molecular symmetry shown by 1H NMR spectrum, and the fragmentation patterns shown by FAB mass spectrum of the octalactam support its monocyclic structure.

• Analytical Science and Technology
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• v.36 no.4
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• pp.198-203
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• 2023

The reaction of cis-protected (Me4en)Pd(II) species with potentially multidentate bis(benzylthio)methylenepropanedioate (L) was carried out to obtain a monometallic compound, [(Me₄en)Pd(L)], in O,O'-coordination mode. The bis(benzylthio)methylene group was bent strikingly from the palladium square plane at the dihedral angle of 70.40°. The physicochemical properties of the present palladium(II) compound were fully characterized by means of infrared and nuclear magnetic resonance spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction measurement.

• Journal of the Korean Magnetic Resonance Society
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• v.18 no.2
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• pp.74-81
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• 2014

The $N_2O_2$ tetradentate Schiff base ligand, N,N'-bis(salicylidene)pentane-1,3-diamine (Salpn), coupled with 1:2 concentration ratio of 1,3-diaminopentane and salicylaldehyde was used to produce a series of macrocyclic Nikel(II) complexes. In the metal complexation, it was observed that Salpn macrocyclic ligand can adopt more than a metal ion giving an unique multinuclear metal complexes including Ni(II)Salpn and $Ni(II)_3(Salpn)_2$. Characteristic IR ${\upsilon}(M-O)$ peaks for Ni(II)Salpn and $Ni(II)_3(Salpn)_2$ were observed to be $1028cm^{-1}$ and $1024cm^{-1}$, respectively. Characteristic UV-Vis absorption ${\lambda}_{max}$ peaks for $Ni(II)_3(Salpn)_2$ were observed to be 241nm and 401 nm. Structural characterization of $Ni(II)_3(Salpn)_2$ by NMR exhibits that the salicylidene ring moiety has two different resonance signals originated from the magnetically asymmetric diligand and trinuclear bis complex. Complete NMR signal assignments and characterizations elucidating structural features of $Ni(II)_3(Salpn)_2$ were described in detail.

• Textile Coloration and Finishing
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• v.30 no.1
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• pp.29-37
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• 2018

Cotton has no adsorption ability for the cationic dye and heavy metal but, if anionized cotton can be made, it will be possible. In this study, to enable the anionisation of cotton fabric, it was modified using sodium vinylsolfonate(SV) as the anionisation reagent, employing a pad-dry-cure(PDC) technique. The effects of curing time, treatment concentrations of urea, sodium hydroxide and SV on the weight increase were experimented and then, the physical characterizations of sulfoethyl cotton(SEC) depending on the finishing conditions were estimated, thus the application possibility of SV as anionisation reagent was investigated. It was not much changed by anionisation except wrinkle recovery. And the structure of SEC was elucidated by Raman and NMR spectoscopy. The feasibility of using Raman and NMR spectroscopy with the band at $1,043cm^{-1}$, and 50.5ppm, respectively as marker band to determine sulfoethyl group of SEC was reported. The total degree of SV substitution(DSV) was determined via elemental analysis. SEC with diverse total DSV up to 0.066 was obtained. In the thermal decomposition(pyrolysis) by DSC, it can be found that the pyrolysis temperature was about $30^{\circ}C$ lower than that of non-treated cotton fabric.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.71-75
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• 2005

$La_{0.5}Ca_{0.5}MnO_3$ colossal magnetoresistance (CMR) powders and pellets were synthesized by sol-gel process. The structural changes were investigated by FT-IR, CP/MAS $^{13}C$ solid state NMR spectroscopy and XRD. The particle characterization, microstructure of sintered samples, and cation composition of gel powders were studied by FE-SEM/EDS, TEM and ICP-AES. The structure refinement reveals that $La_{0.5}Ca_{0.5}MnO_3$ has orthorhombic, perovskite type unit cell. The magnetic characterizations were identified through measurement of magnetic moment by VSM.

• Journal of the Korean Chemical Society
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• v.56 no.3
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• pp.357-362
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• 2012

5-Nonylsalicylaldoxime and salicylaldehyde are two derivatives of phenolic compounds which are very applicable materials in industries. Formerly the formylation of phenolic derivatives were carried out by Rimer-Tiemann method. In this work both of these two materials were synthesized by magnesium meditated formylation technique and their structural characterizations were compared by instrumental analysis technique. In order to achieve a selectively orthoformylated product, the hydroxyl group of nonylphenol (or phenol) was first modified by magnesium methoxide. The nonylphenol magnesium salt was then formylated by paraformaldehyde. The oximation reaction was finally applied to the prepared nonylsalicylaldehyde magnesium salt by liquid extracting via water and acid washing and other extractions. The solvent was finally removed by evaporation under reduced pressure. Some instrumental analysis such as $^1H$-NMR, GC/MS and FT-IR spectra were taken on the product in order to interpret the reaction characterization quantitatively and qualitatively. The formaldehyde and oxime functional groups of two compounds were investigated through $^1H$-NMR and FT-IR spectra and were compared. The yield of methoxilation was very good and the yields of formylation and oximation reactions were about 90%and 85% respectively. The orthoselectivity of formylation reaction were evaluated by comparing of the relevant spectra. The GC/MS spectra also confirmed the obtained results.

• Journal of the Korean Ceramic Society
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• v.40 no.5
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• pp.434-440
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• 2003

The powders of L $a_{0.8}$C $a_{0.2}$Mn $O_3$ Colossal Magnetoresistance (CMR) materials were synthesized by sol-gel process. Lanthanum(H), Calcium(II) and Manganese(III) 2,4-Pentanedionate were dissolved in a mixed binary solution consisted of propionic acid and methanol with PEG (15 wt%) aqueous solution. The progress of reactions was monitored by FT-IR spectroscopy. The Lao scao.2Mn03 gel powders were annealed at various temperatures. The structural changes were investigated by FT-IR, CP/MAS $^{ 13}$C solid state NMR spectroscopy and XRD. The thermochemical property, particle characterization, microstructure of sintered sample, and cation composition of gel powder were studied by TG/DTA, FE-SEM and ICP-AES. The magnetic characterizations were identified through measurement of magnetic moment by VSM.

• Journal of Integrative Natural Science
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• v.2 no.2
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• pp.65-68
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• 2009

Siloles of considerable current interest, both because of their unusual electronic properties and because of their possible application as electron-transporting materials in devices such as light-emitting diodes (LED's) and chemical sensor. Siloles have been characterized by NMR, FT-IR, and UV-vis absorption spectroscopy. Their optical characteristics have been also investigated using photoluminescence spectroscopy. Thus siloles exhibit a low reduction potential and a low-lying LUMO energy level, attributed to ${\sigma}^*-{\pi}^*$ conjugation arising from the interaction between the ${\sigma}^*$ orbital of the sigma-bonded silicon atom and the $\pi^*$ orbital of the butadiene moiety of the ring.