• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.1990-1994
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• 2013

A novel multi-cationic borane, tri-N-methylpyridinium substituted triarylborane, $[BAr^N_3]I_3$ ($[2]I_3$) ($Ar^N=4-(4-C_5H_4N-Me)-2,6-Me_2-C_6H_2$) was prepared from the corresponding neutral tris-pyridyl borane, $BAr_3$ (2a) ($Ar=4-(4-C_5H_4N)-2,6-Me_2-C_6H_2$). The crystal structure of 2a determined by X-ray diffraction study reveals the presence of tri-coordinate boron center with peripheral pyridyl moieties. The fluoride ion affinity of the cationic borane, $[2]I_3$ was investigated by UV-vis absorption titrations and was compared with that of neutral 2a. While 2a binds fluoride with the binding constant of $1.9{\times}10^2\;M^{-1}$ in $THF/H_2O$ (9:1 v/v) mixture, $[2]I_3$ shows a very high binding constant ($K=1.0{\times}10^8\;M^{-1}$) that is greater by six orders of magnitude than that of 2a in the same medium. This result indicates that the fluorophilicity of triarylborane can be drastically enhanced by multiple pyridinium substitutions.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.4
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• pp.299-304
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• 2008

Thermal decomposition of Ammonia Borane have been investigated with various analytical methods including TGA, TP-MS, DSC. By-products such as aminoborane and borazine were identified during hydrogen release by TGA, TP-MS analysis. $H_2$ release amount was measured at each temperature isothermally, which resulted in 7 wt% $H_2$ release at 130$^{\circ}C$. Moreover, higher temperature enhanced hydrogen release kinetics leading to shortened induction period from 20 min at 95$^{\circ}C$ to 0 min at 130$^{\circ}C$. Melting and decomposition at close temperature (4$^{\circ}C$ difference) caused the formation of thin foam during hydrogen release. Suppression of by-products and thin foam formation during hydrogen release is suggested as critical issues to realize chemical hydrogen storage system with ammonia borane.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.285-285
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• 2013

Recently, hexagonal boron nitride (h-BN), which is III-V compound of boron and nitride by strong covalent sp2 bonds has gained great interests as a 2 dimensional insulating material since it has honeycomb structure with like graphene with very small lattice mismatch (1.7%). Unlike graphene that is semi-metallic, h-BN has large band gap up to 6 eV while providing outstanding properties such as high thermal conductivity, mechanical strength, and good chemical stability. Because of these excellent properties, hBN can potentially be used for variety of applications such as dielectric layer, deep UV optoelectronic device, and protective transparent substrate. Low pressure and atmospheric pressure chemical vapor deposition (LPCVD and APCVD) methods have been investigated to synthesize h-BN by using ammonia borane as a precursor. Ammonia borane decomposes to polyiminoborane (BHNH), hydrogen, and borazine. The produced borazine gas is a key material that is a used for the synthesis of h-BN, therefore controlling the condition of decomposed products from ammonia borane is very important. In this paper, we optimize the decomposition of ammonia borane by investigating temperature, amount of precursor, and other parameters to fabricate high quality monolayer h-BN. Synthesized h-BN is characterized by Raman spectroscopy and its absorbance is measured with UV spectrophotometer. Topological variations of the samples are analyzed by atomic force microscopy. Scanning electron microscopy and Scanning transmission Electron microscopy are used for imaging and analysis of structures and surface morphologies.

• Korean Educational Research Journal
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• v.37 no.1
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• pp.33-45
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• 2016

We propose a research for detection of the fluoride ion using borane compounds. Based on the Lewis acid-base reaction, we discussed the fundamental of sensing for fluoride ion. One of the important aspects in the chemistry of organoboranes is their behaviors as Lewis acids, which is a result of the vacant $2p_{\pi}$ orbital on the tricoordinate boron center. The electronic interaction between boron atoms and ${\pi}$-orbitals of donor molecules, constructed from the carbon 2p orbitals, is generally strong. Boron atoms can reach the desired octet configuration either through ${\pi}$-overlap with a suitable X or through formation of Lewis acid-Lewis base complexes.

• Carbon letters
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• v.5 no.3
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• pp.113-117
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• 2004

The mesophase pitch was prepared by adding 1~10 wt% of the borane-pyridine complex (BPC) to decant oil. It was prepared in a reactor held at $450^{\circ}C$ for 2 h in $N_2$ atmosphere. The mesophase pitches were analyzed using thermogravimetric analyzer (TGA), melting point apparatus, X-ray diffraction (XRD) and polarized optical microscope. The coke yield, softening point, toluene insoluble, density and content of anisotropy in the mesophase pitches were increased with BPC contents. The XRD profiles did not show any effect of addition of BPC on the formation of mesophase pitch, while the crystallinity of mesophase pitches was increased when the materials were heat treated with boron compound.

• Bulletin of the Korean Chemical Society
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• v.10 no.1
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• pp.12-15
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• 1989

Various tertiary amides have been subjected to the reduction by borane-THF in the presence of trimethyl borate at $0^{\circ}C$ and the product ratio of alcohol and amine have been analyzed in order to find out the possible way to obtain one product exclusively on the basis of the structure of amides. In the case of N,N-dimethyl derivatives of both linear aliphatic and aromatic amides the corresponding alcohols were produced predominantly. However, the bulkier tertiary amides such as N,N-diethyl and hindered acid derivatives afforded amines rather than alcohols. The mechanism of borane reduction of tertiary amides is also discussed.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.675-678
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• 2003

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.140-140
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• 2008

Ni-B 합금 도금은 여러 가지 Boron 화합물을 이용한 무전해 도금에 비중을 두고 많은 연구가 이루어졌다. 전해 도금은 무전해 도금과 비교하여 욕조성이 단순하고 관리가 용이하며 하며 넓은 범위의 Boron 함량을 조절할 수 있는 이점이 있다. 본 연구에서는 낮은 Boron 함량의 Ni-B 합금층을 전기도금하여 여러 가지 물성을 연구하였다.

• Journal of the Korean Chemical Society
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• v.22 no.1
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• pp.37-44
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• 1978

The effect of lithium chloride on the borane reduction of organic compounds was studied for three ketones, seven acid derivatives, three epoxides and cyclohexene in tetrahydrofuran at $0^{\circ}$. When compared with borane itself, borane-lithium chloride system enhanced the rates of reductions markedly of 2-heptanone, acetophenone, benzoyl chloride, phthalic anhydride, and three epoxides, whereas the reductions of benzophenone, four esters and cyclohexene showed little or no effect. $BH_3$-LiCl (1 : 0.1) reduced styrene oxide in 2 hr at $0^{\circ}$ to give 94.2 % yield of alcohols, 1-to 2-phenylethanol ratio being 60.8 to 39.2. And in the reduction of cyclohexene oxide, $BH_3$-LiCl (1 : 0.1) gave a quantitative yield of cyclohexanol in 2 hr at $0{\circ}$, however $BH_3$-LiCl (1 : 1) gave 58 % cyclohexanol and 42 % 2-chlorocyclohexanol. In the reduction of cyclohexene oxide, lithium nitrate showed no rate enhancement even when the salt was added in large excess. A formation of lithium chloroborohydride in the$BH_3$-LiCl system is suggested.

• Journal of the Korean Chemical Society
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• v.26 no.5
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• pp.340-348
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• 1982

The presence of 10 mole percent triphenyl borate accelerated dramatically the rate of reduction of structurally different sulfoxides with borane in tetrahydrofuran at room temperature, compared to the slow reduction with borane itself. Tetramethylene sulfoxide underwent complete reduction in 5 min and diethyl sulfoxide, dibenzyl sulfoxide and benzylphenyl sulfoxide were reduced quantitatively within 1h, whereas the reduction of diphenyl sulfoxide was rather slow, giving diphenyl sulfide in 90% yield in 24h. Boron trifluoride etherate and triethyl borate were less effective than triphenyl borate. A possible mechanism is presented.