• Polymer(Korea)
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• v.25 no.6
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• pp.803-810
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• 2001

A nonlinear optical hyperbranched polyester (PE-Azo/Hyper) was synthesized from 4-[N,N-bis(hydroxyethyl)amino-4'-formyl] azobenzene and cyanoacetic acid by a Knoevenagel polycondensation using 4-(dimethylamino) pyridine as a base. The resulting polymer was soluble in polar aprotic solvents such as N,N-dimethylformamide and 1-methyl-2-pyrrolidinone and could be processed into optical quality films by spin coating. The molecular weight was determined to be $M_w$=61,800 ($M_W/M_n{=1.86}$) by gel permeation chromatography using polystyrene as a standard. No melting point was detected by differential scanning Calorimeter, indicating that this polymer presents an amorphous state. It shows a glass transition temperature of $121^{\circ}C$. The second-order nonlinear optical coefficient $d_{33}$ of the poled polymer determined by the second harmonic generation at 1064 nm was 25.4 pm/V.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.718-722
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• 2011

2,4'-Bipyridinium dichromate [$(C_{10}H_8N_2H)_2Cr_2O_7$] was synthesized by the reaction of 2,4'-bipyridinie with chromium trioxide in $H_2O$. The structure was characterized by IR and ICP analysis. The oxidation of benzyl alcohol using 2,4'-bipyridinium dichromate in various solvents showed that the reactivity increased with the increase in the order of the dielectric constant (${\varepsilon}$), in the order : cyclohexene < chloroform < acetone < N,N'-dimethylformamide. In the presence of hydrochloric acid, 2,4'-bipyridinium dichromate effectively oxidized benzyl alcohol and its derivatives ($p-CH_3$, H, m-Br, $m-NO_2$) in N,N'-dimethylformamide. Electron-donating substituents accelerated the reaction, whereas electron acceptor groups retarded the reaction. The Hammett reaction constant (${\rho}$) was -0.65 at 303 K. The observed experimental data was used to rationalize the hydride ion transfer in the rate-determining step.

• Journal of Pharmaceutical Investigation
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• v.6 no.2
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• pp.83-87
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• 1976

Microanalysis of rodenticide by visible absorption method was attempted. The following procedure was found to be very simple and to give accurate results. RH-28787 was added to dimethylformamide (DMF), and extracted after stirring for about 20 minutes in extractor $(30^{\circ}C)$. After extraction, the absorbance of DMF solution, was measured at 346 nm by using spectrophotometer. The result agrees closely with the experimentally determined value by means of the gas chromatograph.

• Archives of Pharmacal Research
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• v.5 no.2
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• pp.103-106
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• 1982

By the reaction of 15 with 3-halohydantoins (4-14) in N, N-dimethylformamide, which were prepared from corresponding hydantoins, 3-bromo-5, 5-dimethylhydantoin was found to be the most convenient reagent for halolactonization reaction.

• Journal of the Korean Chemical Society
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• v.37 no.7
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• pp.672-676
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• 1993

The complexation of bilirubin with zinc(II) and copper(II) ions was studied spectrophotometrically. In the zinc(II)-bilirubin (Zn-BR) system, complex is formed, but the copper(II) ion oxidizes bilirubin to biliverdin and then to the further oxidation products. The electrochemical reduction behavior of ZN-BR complex has been investigated with DC polarography and cyclic voltammetry. The three polarographic waves were obtained for the reduction of ZN-BR complex in DMF solution. Thde reduction current of the third wave was diffusion current, but that of the first and the second waves contained a little kinetic current.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.345-352
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• 2014

Objectives: This study is aimed to describe the current situation about urinary biomarker N-methylformamide(NMF) for workers exposed to N,N-dimethylformamide(DMF) according to industrial classification. Materials: Special health examination records of the workers who had undergone urinary biological monitoring in 2013 were collected. The numbers and percentage of workers, whose urinary NMF values were above the limit of detection(LOD) and above the biological exposure index(BEI) were calculated. Health relatedness with DMF as judged by their doctors was also described. All description was classified according to the $9^{th}$ Korean Standard Industrial Classification(KSIC). Results: It appeared that most workers exposed to DMF belong to manufacturing section(80.7%). The geometric mean(GM) values of urinary NMF were 6.25 mg/L, 3.54, and 3.86 for the manufacturing section, professional, scientific and technical activities section, and for the construction section respectively. In detail, it seemed that division of textiles(except apparel) (GM 7.51 mg/L), division of leather, luggage and footwear(11.59 mg/L), and division of rubber and plastic products(6.89 mg/L) were highly exposed to DMF with a high percentage of workers with urinary NMF values above BEI. This was probably due to the effect of skin absorption that the division of leather, luggage and footwear showed the highest urine NMF GM. Conclusions: It seemed that workers in manufacture industries such as textile, leather, luggage, footwear, rubber and plastic products were highly exposed to DMF. So, efforts should be focused on those industries in order to effectively diminish worker's exposure. Further studies to compare DMF air-monitoring with bio-monitoring according to industrial classification should be considered.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.153-157
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• 2005

4-(Dimethylamino)pyridinium dichromate was synthesized by the reaction of 4-(dimethylamino)pyridine with chromium(VI)trioxide in $H_2O$, and characterized by IR, EA and ICP. The oxidation of benzyl alcohol using 4-(dimethylamino)pyridinium dichromate in various solvents showed that the reactivity increased with the increase of the dielectric constant, in the order: cyclohexen < chloroform < acetone < N,N-dimethylformamide. In the presence of hydrochloric acid(HCl), 4-(dimethylamino)pyridinium dichromate oxidized benzyl alcohol and its derivatives ($p-CH_3$, H, m-Br, $m-NO_2$) smoothly in N,N-dimethylformamide. Electron-donating substituents accelerated the reaction, whereas electron-withdrawing groups retarded the reaction. The Hammett reaction constant($\rho$) was -0.70 at 303K. The observed experimental data have been rationalized as follows: the proton transfer occurs after the prior formation of a chromate ester in the rate-determining step.

• Journal of the Korean Chemical Society
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• v.45 no.4
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• pp.325-333
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• 2001

The 4-substituted tetrazolo[1,5-a]quinoxalines were synthesized from 4-chlorotetrazolo-[1,5-a]quinoxaline(8) or 4-hydrazinotetrazolo[1,5-a]quinoxaline(9). Refluxing of the tetrazolo[1,5-a]quinoxaline(12) in N,N-dimethylformamide gave the 1,2,4-triazolo[3,4-c]tetrazolo[1,5-a]quinoxaline(13), which was also obtained by the reaction of compound 9 with ethyl chloroformate in N,N-dimethylformamide. The reaction of compound 9 with isothiocyanates in ethanol provided the tetrazolo[1,5-a]quinoxalines(14), whose reaction with dimethyl acetylenedicarboxylate afforded the tetrazolo[1,5-a]quinoxalines(15). The tetrazolo [1,5-a]quinoxalines(18) were obtained by the reaction of compound 9 with alkyl (ethoxymethylene)cyanoacetates. Some of the compounds showed antibacterial, antifungal or algicidal activities against some strains.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.462-469
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• 2012

Cr(VI)-4,4'-bipyridine complex(4,4'-bipyridinium dichromate) was synthesized by the reaction of 4,4'-bipyridine with chromium trioxide in H2O, and characterized by IR, ICP. The oxidation of benzyl alcohol using 4,4'-bipyridinium dichromate in various solvents showed that the reactivity increased with the increase of the dielectric constant(${\varepsilon}$), in the order: cyclohexene$CH_3$, H, m-Br, m-$NO_2$) smoothly in N,N'-dimethylformamide. Electron-donating substituents accelerated the reaction, whereas electron acceptor groups retarded the reaction. The Hammett reaction constant(${\rho}$) was -0.63(303K). The observed experimental data have been rationalized as follows; the proton transfer occurs after the prior formation of a chromate ester in the rate determining step.

• Korean Journal of Crystallography
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• v.15 no.2
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• pp.78-82
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• 2004

The solvothermal reaction of zinc(H) nitrate $(Zn(NO_3)_2\;{\cdot}\;6H_2O)$ with $ATP(2-aminoterephthalate,\;H_2N-C_6H_3-1,4-(COO)_2)$ in a mixture of solvents of DMF and ethanol, in the presence of benzene, gave a 2 dimensional zinc polymer [Zn(ATP) (DMF)] (1). X-ray structure determination revealed that two zinc metals and four ATP ligands form the paddle-wheel SBUs, which are linked by the ATP ligands to give a 2-D square-grid network. Each square grid has approximate dimensions of $11.1\times11.1\;{\AA}$ based on Zn metals. Benzene was required to produce high-quality crystals of polymer 1.