• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3880-3886
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• 2011

The nucleophilic substitution reactions of diisopropyl thiophophinic chloride (3) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $65.0^{\circ}C$. The anilinolysis rate of 3 is rather slow to be rationalized by the conventional stereoelectronic effects. The obtained deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) are secondary inverse ($k_H/k_D$ = 0.80-0.96). The anilinolyses of ten P=S systems in MeCN are reviewed on the basis of DKIEs and selectivity parameters to obtain systematic information on the DKIEs and mechanism for thiophosphoryl transfer reactions. The steric effects of the two ligands on reactivity, DKIEs, mechanism, and substituent effects of the nucleophile (X) on the DKIEs are discussed.

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.843-847
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• 2012

The nucleophilic substitution reactions of dibutyl chlorothiophosphate (4S) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $55.0^{\circ}C$. The obtained deuterium kinetic isotope effects (DKIEs;$k_H/k_D$) are primary normal ($k_H/k_D$ = 1.10-1.35). A concerted mechanism involving predominant frontside nucleophilic attack is proposed on the basis of the primary normal DKIEs and selectivity parameters. Hydrogen bonded, four-center-type transition state is proposed. The steric effects of the two ligands on the anilinolysis rates of the chlorothiophosphates are discussed. The anilinolyses of P=S systems are compared with those of their P=O counterparts on the basis of the reactivities, thio effects, selectivity parameters, and DKIEs.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3245-3250
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• 2011

The nucleophilic substitution reactions of diisopropyl chlorophosphate (3) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $55.0^{\circ}C$. The anilinolysis rate of 3 is rather slow to be rationalized by the conventional stereoelectronic effects. The obtained deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) are secondary inverse ($k_H/k_D$ = 0.71-0.95) with maximum magnitude at X = H.A concerted mechanism involving predominant backside nucleophilic attack is proposed on the basis of the secondary inverse DKIEs.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4403-4407
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• 2011

The nucleophilic substitution reactions of dipropyl chlorothiophosphate (3) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $55.0^{\circ}C$. The obtained deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) are primary normal ($k_H/k_D$ = 1.11-1.35). A concerted mechanism involving predominant frontside nucleophilic attack is proposed on the basis of the primary normal DKIEs and selectivity parameters. Hydrogen bonded, four-center-type transition state is proposed. The steric effects of the two ligands on the anilinolysis rates of various substrates are discussed.

• 한국세라믹학회지
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• 제35권11호
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• pp.1233-1239
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• 1998

Gas phase compositions of the hot filament-assisted diamond CVD reaction were analyzed by on-line quadrupole mass analysis(QMA) technique. D2 isotope experiments showed that methance molecules were decomposed into atomic state and then recombined in to acetylene during transport the probe line. Although acetylene or ethylene was supplied instead of methane similar gas compositions were obtained when filament temperature was above 1500$^{\circ}C$ Therefore this system could be assumed near thermal equilibrium state. Filament temperature and reaction pressure variation experiments exhibited the same tendency between acetylene concentration and diamond growth rate and these results implied that acetylene molecule played the role of the reactive species in the diamond CVD reaction.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3355-3360
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• 2011

The nucleophilic substitution reactions of 1,2-phenylene phosphorochloridate (1) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $-15.0^{\circ}C$. The studied substrate of 1,2-phenylene phosphorochloridate is cyclic five-membered ring of phosphorus ester, and the anilinolysis rate of 1 is much faster than its acyclic analogue (4: ethyl phenyl chlorophosphate) because of extremely small magnitude of the entropy of activation of 1 compared to 4. The Hammett and Bronsted plots exhibit biphasic concave upwards for substituent X variations in the nucleophiles with a break point at X = 3-Me. The values of deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) change from secondary inverse ($k_H/k_D$ < 1) with the strongly basic anilines to primary normal ($k_H/k_D$ > 1) with the weakly basic anilines. The secondary inverse with the strongly basic anilines and primary normal DKIEs with the weakly basic anilines are rationalized by the transition state (TS) variation from a predominant backside attack to a predominant frontside attack, in which the reaction mechanism is a concerted $S_N2$ pathway. The primary normal DKIEs are substantiated by a hydrogen bonded, four-center-type TS.

• 지질공학
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• 제12권3호
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• pp.285-294
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• 2002

피압대수층내 질소함유 원인규명을 위하여 질산성질소(NO3-N), 질소, 산소, 및 수소안정동위원소를 이용하였다. 전형적인 피압대수층인 먹는샘물업체의 지하수의 질산성질소를 분석한 결과, 1988-2001년 기간동안 60 여개의 먹는샘물 제조업체의 질산성질소의 총평균은 0.95 mg/$\ell$로서 매우 낮다. 이 기간동안 질산성질소의 함량이 지속적으로 2 mg/$\ell$ 이상으로 나타난 6개소에 대한 안정동위원소 분석결과, 산소동위원소 $\delta$8O 값은 -8.3~-11$\textperthousand$범위, 수소동위원소 $\delta$D 값은 약 -60~-75$\textperthousand$ 범위로서 전국 먹는샘물 지하수의 평균치와 흡사하다. 질소동위원소 $\delta$15N값은 -11.8~-5.1$\textperthousand$ 범위로서 가벼운 특성을 보여주고 있다. 따라서 본 연구대상 지하수의 질산성질소는 가축분뇨나, 유기질소, 또는 비료기원일 가능성은 없는 것으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2628-2632
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• 2011

The nucleophilic substitution reactions of Y-O-aryl phenyl phosphonochloridothioates with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are kinetically investigated in acetonitrile at $55.0^{\circ}C$. The deuterium kinetic isotope effects (DKIEs) invariably increase from an extremely large secondary inverse ($k_H/k_D$ = 0.439; min) to a primary normal ($k_H/k_D$ = 1.34; max) as both substituents of nucleophile (X) and substrate (Y) change from electron-donating to electron-withdrawing. These results are opposite to the DKIEs on Y-O-aryl methyl phosphonochloridothioates, and can be rationalized by the gradual transition state (TS) variation from backside to frontside attack. The trigonal bipyramidal pentacoordinate TS is proposed for a backside attack, while the hydrogen-bonded, four-center-type TS is proposed for a frontside attack. The negative values of the cross-interaction constants (${\rho}_{XY(H)}$ = -0.38 for $XC_6H_4NH_2$ and ${\rho}_{XY(D)}$ = -0.29 for $XC_6H_4ND_2$) indicate that the reactions proceed by a concerted $S_N2$ mechanism.

• 한국해양환경ㆍ에너지학회지
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• 제15권3호
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• pp.247-256
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• 2012

원유의 탄소안정동위원소비는 증발, 생물분해, 용해 등 풍화작용에 의해 큰 영향을 받지 않는 것으로 알려져 있어, 유출유의 기원을 확인하는 추적자로서 널리 사용되고 있다. 본 연구에서는 국내에 수입되고 있는 유류 중 주요 14종 원유와 제품유 1종의 분자단위 유지문 지표와 탄소안정동위원소비 조성을 분석하고, 이를 유지문으로 활용하여 각 지표의 유류 간 식별력을 비교하였다. Bintulu 원유와 제품유(B-C(1%)) 만이 다른 원유와 구별되는 고유한 alkane 분포패턴을 보였고, 나머지 원유들은 매우 유사한 분포특성을 나타내었다. Alkane 분자지표를 사용하였을 때, 원유를 크게 3개 그룹으로 분류할 수 있었으나 그룹 내 식별은 불가능하였다. PAHs 분자지표인 C2D/C2P와 C3D/C3P 이중지수를 이용해서 A.L., A.S.L., Foroozan, B-C(1%)을 다른 원유들로부터 구별할 수 있었으며, 4-mD/1-mD와 2/3-mD/1-mD 이중지수는 A.S.L., Bintulu, Oman 원유를 뚜렷이 식별할 수 있었다. 하지만 나머지 원유들은 매우 유사한 값을 가지고 있어서 원유 간 식별이 어려웠다. 반면 탄소안정동위원소비를 활용한 식별법은 A.L., A.M., Qatar-Marine, B-C(1%)를 제외한 나머지 모든 원유 사이의 식별을 가능하게 하였다. 개별화합물의 탄소안정동위원소 조성비를 활용한 유지문 분석법은 기존의 PAHs와 alkane의 대표적인 분자지표들과 비교했을 때 상대적으로 높은 원유 간 식별력을 보여 주었다.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4361-4365
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• 2011

The nucleophilic substitution reactions of bis(N,N-dimethylamino) phosphinic chloride (3) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $65.0^{\circ}C$. The anilinolysis rate of 3 is rather slow to be rationalized by the conventional stereoelectronic effects. The magnitudes of ${\rho}_X$ (= -6.42) and ${\beta}_X$ (= 2.27) values are exceptionally great. The deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) are secondary inverse ($k_H/k_D$ = 0.69-0.96). A concerted $S_N2$ mechanism involving a backside attack is proposed on the basis of secondary inverse DKIEs and the variation trend of the $k_H/k_D$ values with X. The anilinolyses of six phosphinic chlorides in MeCN are briefly reviewed by means of DKIEs, steric effects of the two ligands, positive charge of the reaction center phosphorus atom, and selectivity parameters to obtain systematic information on phosphoryl transfer reaction mechanism.