• Journal of Photoscience
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• 제12권2호
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• pp.101-107
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• 2005

Infrared multiphoton dissociation of $CHCl_2F$ was studied using $CO_2$ laser excitation. Three products, $C_2Cl_2F_2$, $C_2ClF_3$, and $C_2HClF_2$, were identified by the analysis of the gas mixture from the photoreaction of $CHCl_2F$. The dependence of the reaction probability on added Ar gas pressure and excitation laser pulse energy was investigated. At low pressure (< 10 torr), the reaction probability increased as Ar pressure increased due to the rotational hole-filling effect, while it diminished with the increase of Ar pressure at high pressure (> > 20 torr) due to the collisional deactivation. The ratio of two products $(C_2ClF_3/C_2Cl_2F_2)$ decreased at low pressure (< 10 torr) and increased at high pressure (> 20 torr) with the increase of Ar pressure. The log-log plot of the reaction probability vs. laser pulse energy (${\\phi}$) was found to have a linear relationship, and its slope decreased as the added Ar pressure was increased. The reaction mechanisms for product formation have been suggested and validated by experimental evidences and considering the energetics. Fluorine-chlorine exchange reaction in the intermediate complex has been suggested to explain the formation of $C_2ClF_3$.

• 대한화학회지
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• 제11권3호
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• pp.89-93
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• 1967

플루오르벤젠과 일염화요오드, 일브롬화요오드, 브롬 또는 염소의 각 系를 사염화탄소 용액에서 分光光度法에 의하여 연구한 결과, $C_6H_5F{\cdot}ICl$, $C_6H_5F{\cdot}IBr$, $C_6H_5F{\cdot}Br_2$, 또는 $C_6H_5F{\cdot}Cl_2$의 錯物이 형성됨을 알았다. 이들 錯物형성에 대한 실온에서의 평형상수는 각각 0.161, 0.072, 0.045 및 0.035 l $mole^{-1}$이다. 이 결과와 문헌에 보고된 연구결과를 종합적으로써 이러한 착물의 상대적 안정도가 다음 순으로 감소함을 알 수 있었다. ICl>IBr>$I_2$>$Br_2$>$Cl_2$ $C_6H_6$>$C_6H_5Br$>$C_6H_5Cl$>$C_6H_5F$

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3274-3278
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• 2013

$CF_2Cl{\cdots}Cl$, an elusive photo-isomer of $CF_2Cl_2$, has been observed in matrix IR spectra from the precursors exposed to radiation from laser ablation of transition-metals. Other plausible products, $CFCl_2{\cdots}F$ and $FClC{\cdots}F-Cl$ are not detected due to their considerably higher energies. Parallel to its previously reported analogues, the C-X bonds are considerably stronger than those of the reactant, and particularly the Cl atom that is weakly bound to the residual Cl atom forms an unusually strong carbon-halogen bond. NBO analysis reveals that the C-Cl bond is a true double bond, and the weak $Cl{\cdots}Cl$ bond is largely ionic, $F_2C=Cl^{\delta+}{\cdots}Cl^{\delta-}$. IRC computation reproduces smooth inter-conversion between the reactant and product, and the transition state is energetically close to the product, consistent with its prompt disappearance in the early stage of photolysis.

• 한국결정학회지
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• 제7권2호
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• pp.113-119
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• 1996

Re(O)(PPh3)2Cl3과 2,3,4,5,6-pentafluoroaniline (C6F5NH2)의 반응으로 Re(NC6F5)(PPh3)2Cl3 생성물을 얻었다. 이 화합물의 구조를 1H-NMR, 원소분석, 그리고 X-ray 회절법으로 규명하였다. 화합물을 사방정계로 (Pna21, a=18.763Å, b=14.737(2)Å, c=16.707(3)Å, Z=4) 결정화되었다. 최소자승법으로 구조를 정밀화한 결과 신뢰도는 R(wR2) = 0.0455(0.1148)였다.

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.583-592
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• 2003

The gas phase identity nucleophilic substitution reactions of halide anions (X = F, Cl, Br) with cyclopentadienyl halides (1) are investigated at the B3LYP/6-311+G**, MP2/6-311+G** and G2(+)MP2 levels involving five reaction pathways: σ-attack $S_N2$, β-$S_N$2'-syn, β-$S_N$2'-anti, γ-$S_N$2'-syn and γ-$S_N$2'-anti paths. In addition, the halide exchange reactions at the saturated analogue, cyclopentyl halides (2), and the monohapto circumambulatory halide rearrangements in 1 are also studied at the same three levels of theory. In the σ-attack $S_N2$ transition state for 1 weak positive charge develops in the ring with X = F while negative charge develops with X = Cl and Br leading to a higher energy barrier with X = F but to lower energy barriers with X = Cl and Br than for the corresponding reactions of 2. The π-attack β-$S_N$2' transition states are stabilized by the strong $n_C-{\pi}^{*}_{C=C}$ charge transfer interactions, whereas the π-attack γ-$S_N$2' transition states are stabilized by the strong $n_C-{\sigma}^{*}_{C-X}$ interactions. For all types of reaction paths, the energy barriers are lower with X = F than Cl and Br due to the greater bond energy gain in the partial C-X bond formation with X = F. The β-$S_N$2' paths are favored over the γ-$S_N$2' paths only with X = F and the reverse holds with X = Cl and Br. The σ-attack $S_N2$ reaction provides the lowest energy barrier with X = Cl and Br, but that with X = F is the highest energy barrier path. Activation energies for the circumambulatory rearrangement processes are much higher (by more than 18 kcal $mol^{-1}$) than those for the corresponding $S_N2$ reaction path. Overall the gas-phase halide exchanges are predicted to proceed by the σ-attack $S_N2$ path with X = Cl and Br but by the β-$S_N$2'-anti path with X = F. The barriers to the gas-phase halide exchanges increase in the order X = F < Br < Cl, which is the same as that found for the gas-phase identity methyl transfer reactions.

• Nuclear Engineering and Technology
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• 제2권4호
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• pp.269-272
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• 1970

순도 99.98%의 LiF 분말에서 열형광을 검출하였으며 이 때 glow curve의 Peak는 12$0^{\circ}C$, 22$0^{\circ}C$ 및 30$0^{\circ}C$에 있다. 이 LiF 분말에 중량비로 2%(mol 비로 4%)의 MgC1$_2$를 첨가하여 소결시킨 LiF 분말은 비약적으로 강한 열형광을 발휘하였으며 그 flow curve의 특성이 상세하게 조사되었다. 열형광선량계로서 이용되고 있는 LiF는 Mg, Mn 등의 불순물에 의한 전자 trap을 가지고 있는 것이 알려져 있으며 이 실험결과는 이들 불순물중의 하나인 Mg가 확실히 LiF의 결정내에 확신된 것을 시사한다. 소결시간의 효과를 glow curve에서 명확하게 검출하였고 또한 원료인 MgC1$_2$도 열형광을 발휘한다는 것이 이 glow curve를 얻음으로써 확인되었다.

• 대한화학회지
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• 제36권2호
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• pp.248-254
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• 1992

에탄올 용매 중에서, 착물 $[({\eta}^5-C_5Me_5)RuCl_2]_2$ (1)에 대하여 과량의 포스핀을 반응시켜 비스(포스핀)루테늄 유도체$({\eta}^5-C_5Me_5)Ru(PR_3)_2Cl(PR_3=PMe_3,\; PMe_2Ph,\;PEt_3,\;PMePh_2$, 1/2DPPE, 1/2DPPB) (2a${\sim}$2f)를 합성하였다. 이 유도체들은 에탄올 용매 중에서 $NaBH_4$와 반응하여 상응하는 황색의 착수소화물 $({\eta}^5-C_5Me_5)Ru(PR_3)_2Hl(PR_3=PMe_3,\;PEt_3,\;PMePh_2$, 1/2 DPPE, 1/2DPPB) (3a${\sim}$3e)을 생성한다. 착염화물 (2a${\sim}$2f)와 착수소화물 (3a∼3e)는 모두 결정으로 얻어졌으며, IR, $^1H-NMR$ 그리고 원소분석으로 동정되었다.

• 한국해양공학회지
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• 제7권2호
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• pp.131-140
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• 1993

To study the corrosion fatigue begavior of T.M.C.P. steel, the rotary bending fatigue test with the change of concentration of NaCl solution was carried out. Fatigue life in the corrosion environment is decreased markedly in comparision with that in the air. Fatigue limit in the air was about 225 MPa. In case of 3.5% NaCl solution fatigue life could be expressed as .sigma./sub f/=10,392 * (N/sub f/)/sup -o.2923 . According to the paris's rule, crack growth rates could be expressed as da/dN=2.62.*10/sup -7/ .DELTA. K/sup 1.09/(3.5% NaCl solution), da/dN=1.95 *10/sup -7 .DELTA. K/sup 1.05/(1% NaCl solution), da/dN=2.62 * 10/sup -7/.DELTA./sup 0.72/(0.01% NaCl solution) with da/dN expressed in mm/cycle and .DELTA.K in MPa.GAMMA.m. The crack growth rate in the corrosion environment was highest under 3.5% NaCl solution.

• 대한화학회지
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• 제24권2호
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• pp.108-114
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• 1980

정전기적모델과 결합의 단순한 부가성을 이용하여 아주 극성인 화합물의 표준생성열$({\Delta}H_f\;^{\circ})$를 계산하는 간단한 방법을 제안하였다. 이 ${\Delta}H_f\;^{\circ}$에 대한 할로메탄의 bond 기여도는 각각 ${\Delta}H_f\;^{\circ}(C-F)=-36.44\;kcal/mole,\;{\Delta}H_f\;^{\circ}(C-Cl)=-2.57\;kcal/mole,\;{\Delta}H_f\;^{\circ}(C-Br)=5.32\;kcal/mole,\;{\Delta}H_f\;^{\circ}(C-I)=19.18\;kcal/mole,\;and\;{\Delta}H_f\;^{\circ}(C-H)=-3.61\;kcal/mole$로 얻어졌고 이 갑들과 정전기적 에너지들로부터 계산한 ${\Delta}H_f\;^{\circ}$는 실험치와 잘 일치함을 보였다.

• 한국결정학회지
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• 제12권1호
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• pp.10-13
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• 2001

Compound PdCl₂(PhCN)₂(1) reacted with tert-butylamine(t-BuNH₂) to give trans-[PdCl₂(t-BuNH₂)₂] (2) Compound 2 was characterized by spectroscopy (¹H-NMR, /sup 13/C{¹H}-NMR, and IR) and X-ray diffraction. Crystallographic data for f2: monoclinic space group p2₁/c, a=6.298(1)Å, b=20.740(2)Å, c=10.731(1)Å, β=92.58(1)°, Z=4, R(wR₂)=0.0207(0.0543).