• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.98-104
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• 1993

The paramagnetic organoruthenium(III) complexes $({\eta}^5-C_5Me_5)RuCl_2(PR_3) (PR_3 = PMe_3,\;PEt_3,\;PiPr_3,\;PCy_3,\;PMe_2Ph,\;PMePh_2,\;PPh_3,\;P(p-C_6H_4CH_3)_3$, DPPE, DPPB, Py) (2a∼2k) were synthesized by the reaction of $[({\eta}^5-C_5Me_5)RuCl_2]_2$ (1) with 1 equivalent of the corresponding phosphines $(PR_3)$. The effective magnetic moment ((${\mu}_{eff} = 1.65∼2.07 B.M.$)) derived from the magnetic susceptibility measurements of the complexes (2a∼2k) were consistent with the presence of a "single" unpaired electron in the molecule. Treatment of dichlororuthenium (III) complex ({\eta}^5-C_5Me_5)RuCl_2(PR_3)$ (2) (i) with KBr in acetone afforded the dibromoruthenium (III) complex $({\eta}^5-C_5Me_5)RuBr_2(PR_3) (PR_3 = PPh_3)$, (ii) with sodium amalgam in diethylether led to the bis(phosphine) derivatives $({eta}^5-C_5Me_5)RuCl(PR_3)_2 (PR_3 = PMe_3,\;PMePh_2)$, and (iii) with carbonmonoxide gave to the carbonyl derivatives $({\eta}^5-C_5Me_5)RuCl(PR_3)(CO) (PR_3 = PMe_3,\;PPh_3)$.

• Bulletin of the Korean Chemical Society
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• v.17 no.2
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• pp.138-142
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• 1996

The transition metal carbonylate, PPN+(${\eta}^5-MeCp)Mn(CO)_2Cl^-$ undergoes a novel ligand substitution reaction with PR3 (R=Me, Et, OEt, $C_6H_5$ in THF at elevated temperatures (40 $^{\circ}C$ up to 60 $^{\circ}C)$ under the pseudo-first-order reaction conditions (usually 20-fold excess of PR3 with respect to metal carbonylate concentrations) where chloride is displaced by PR3. The reaction follows overall first order dependence on [(${\eta}^5-MeCp)Mn(CO)_2Cl^-$]; however, the negative entropy changes of activation (${\Delta}S^{\neq}$=-19.3 e.u. for $P(OEt)_3$; ${\Delta}S^{\neq}$=-16.4 e.u. for $PPh_3$) suggest the existence of the intermediate, ((η3-MeCp)Mn(CO)2(THF)Cl-, which eventually transforms to the product (${\eta}^5-MeCp)Mn(CO)_2(PR_3)$.

• Journal of Life Science
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• v.25 no.1
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• pp.37-43
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• 2015

We have investigated the effects of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), indole-3-acetic acid (IAA) and methyl jasmonate (MeJA) on the development of aerenchyma in the primary root of maize (Zea mays). Because plant hormones affected the longitudinal organization of the primary root, we need an indicator to direct the positions for comparison between control and hormone-treated roots. Therefore, the zones of the maize primary root were categorized as PR25, PR50 and PR75, where each value indicates the relative position between the root tip (PR0) and the base (PR100). Aerenchyma was not observed at PR25 and PR50 and rarely found at PR75 in the cortex of control roots. The aerenchymal area at PR75 increased in the presence of the ethylene precursor ACC or a natural auxin IAA. On the other hand, MeJA differentially acted on non-submerged and submerged roots. Exogenously applied MeJA suppressed the aerenchyma formation in non-submerged roots. When the primary root was submerged, aerenchymal area expanded prominently. The submergence-induced aerenchyma formation was amplified with MeJA. Lateral root primordia have been known to inhibit aerenchymal death of surrounding cells. All the three hormones stimulating aerenchyma formation as described above did not restore the inhibition caused by lateral root primordia, suggesting that the inhibitory step regulated by lateral root primordia can be located after hormonal signaling steps.

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.248-254
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• 1992

Bis(phosphine)ruthenium derivatives $({\eta}^5-C_5Me_5)RuCl(PR_3)_2(PR_3=PMe_3,\; PMe_2Ph,\;PEt_3,\;PMePh_2$, 1/2DPPE, 1/2DPPB) (2a${\sim}$2f) have been synthesized by the reaction of $[({\eta}^5-C_5Me_5)RuCl_2]_2$ (1) with excessive phosphine in ethanol. The reaction of complexes $({\eta}^5-C_5Me_5)Ru(PR_3)_2Cl\;with\;NaBH_4$ in ethanol gave the corresponding hydride complexes $({\eta}^5-C_5Me_5)Ru(PR_3)_2H (PR_3=PMe_3, PEt_3, PMePh_2$, 1/2 DPPE, 1/2DPPB) (3a${\sim}$3e). Chloride complexes (2a${\sim}$2f) and hydride complexes (3a${\sim}$3e) were isolated as crystals, which were characterized by IR, $^1H-NMR$ , and elemental analysis.

• Bulletin of the Korean Chemical Society
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• v.19 no.4
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• pp.462-466
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• 1998

The homobimetallic anion, $({\eta}^5-MeCp)Mn(CO)_2Mn(CO)_5-M^+\; (M^+=Na^+, PPN^+$) was disrupted by $PR_3\;(R=C_6H_5,\;C_2H_5,\;OCH_3)$ in THF at various temperatures (r.t. ∼65℃) under the pseudo first order reaction conditions where excess of $PR_3$ was employed under a nitrogen atmosphere. For the reaction involving $PPN^+$ analog, Mn-Mn heterolytic cleavage occurred, leading to $PPN^+Mn(CO)_5^-\; and \;({\eta}^5-MeCp)Mn(CO)_2PR_3$ as products; however, in case of $Na^+\; analog,\; Na^+$ seems to play a novel counter ion effect on the disruption reaction by transferring one terminal CO from the $Mn(CO)_5$ moiety on to the $({\eta}^5-MeCp)Mn(CO)_2$ of the corresponding homobimetallic complex, eventually resulting in $Na^+Mn(CO)_4PR_3^-\;and\;({\eta}^5-MeCp)Mn(CO)_3$. This reaction is of overall first order with respect to [homobimetallic complex] with the activation parameters (ΔH≠=23.0±0.7 kcal/mol, ΔS≠= - 8.7±0.8 e.u. for $Na^+$ analog; ΔH≠=28.8±0.4 kcal/mol, ΔS≠=15.7±0.6 e.u. for $PPN^+$ analog reaction).

• Journal of the Korean Vacuum Society
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• v.6 no.3
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• pp.249-254
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• 1997

We investigated characteristics of Fe-doped semi-insulating InP by means of photoreflectance(PR) measurement. The band gap energy($E_0$) and broadening parameter($\Gamma$) from PR signals at 300K are 1.336 eV and 11.2 meV, respectively. As the temperature is decreased from 300 to 80 K, PR signals are varied from an overlapped shape of exciton and 2-dimensional band gap transitions(300 K) to that of exciton transition(80 K). We calculated Varshni coefficient($\alpha=0.94\pm$0.07 meV/K, $\beta=587\pm$35.2 K) and Bose-Einstein coefficient ($a_B=33.6{\pm}2.02meV$ , $\theta=165\pm$33K). After annealing of isothermal and isochronism crystallinity of InP is found to be excellent when annealed at $300^{\circ}C$ for 10~20 min, qualitatively.

• Bulletin of the Korean Chemical Society
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• v.18 no.2
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• pp.213-217
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• 1997

Magnesium reduction of Mo(N-C6H3-2,6-i-Pr2)2Cl2(DME) in the presence of trimethylphosphine led to a mixture of Mo(N-C6H3-2,6-i-Pr2)(PMe3)2Cl3, 1, and Mo2(PMe3)4Cl4, 2. In solution 1 is slowly air-oxidized to Mo(N-2,6-i-Pr2-C6H3)(OPMe3)(PMe3)Cl3, 3. 1 is chemically inert to carbon nucleophiles (ZnMe2, ZnEt2, AlMe3, AlEt3, LiCp, NaCp, TlCp, NaCp*, MeMgBr, EtMgBr), oxygen nucleophiles (LiOEt, LiO-i-Pr, LiOPh, LiOSPh), and hydrides (LiBEt3H, LiBEt3D). Crystal data for 1: orthorhombic space group P212121, a=11.312(3) Å, b=11.908(3) Å, c=19.381(6) Å, Z=4, R(wR2)=0.0463 (0.1067). Crystal data for 2: monoclinic space group Cc, a=18.384(3) Å, b=9.181(2) Å, c=19.118(3) Å, b=124.98(1)°, Z=4, R(wR2)=0.0228 (0.0568). Crystal data for 3: orthorhombic space group P212121, a=11.464(1) Å, b=14.081(2) Å, c=16.614(3) Å, Z=4, R(wR2)=0.0394 (0.0923).

• YAKHAK HOEJI
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• v.32 no.3
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• pp.164-169
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• 1988

$^{13}C$ NMR chemical shifts for 18 ${\alpha}-susbstituted$ toluenes at high dilution in $CCl_4$ solution have been determined. Substituents are as follows: H, Me, Et, n-Pr, iso-Pr, Ph, F, Cl, Br, $NH_2$, NHMe, $NMe_2$, OH, OMe, OCOMe, $CO_2Me$, $CO_2Et$, CN. Those chemical shifts of the methylene carbon of the toluene and the ${\alpha}-carbon$ of the n-butane systems are correlated well. (r=.975, slope=.962)

• Journal of the Korean Chemical Society
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• v.52 no.5
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• pp.476-481
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• 2008

• Bulletin of the Korean Chemical Society
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• v.14 no.6
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• pp.669-673
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• 1993

The CO substitution reactions of the complex, $Cp(S-2,4-Me_2C_5H_5)CrCo$ with $PR_3(PR_3=PMePh_2,\;P(OCH_3)_3,\;PMe_2Ph)$ were investigated spectrophotometrically at various temperatures. From the reaction rates, it was suggested that the CO substitution reaction took place by first-order (dissociative) pathway. Activation parameters in decaline were ${\Delta}H^{\neq}\;=\;22.0\;kcal{\cdot}mol^{-1}$, ${\Delta}S^{\neq}=\;-3.8cal{\cdot}mol^{-1}{\cdot}K^{-1}$. Unusually low value of ${\Delta}S{\neq}$ suggests an ${\eta}^5-S{\to}{\eta}^5-U$ conversion of the pentadienyl ligand. This suggestion was confirmed by the Extended-Huckel molecular orbital (EHMO) calculations, which revealed that the total energy of $Cp(S-2,4-Me_2C_5H_5$)CrCO is about 0.42 kcal/mol more lower than that of $Cp(U-2,4-Me_2C_5H_5)CrCO$ and the energy of $[Cp(U-2,4-Me_2C_5H_5)Cr{\cdots}CO]^{\neq} $ transition state is about 2.43 kcal/mol lower than that of $[Cp(S-2,4-Me_2C_5H_5)Cr{\cdots}CO]^{\neq}$ transition state.