• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.53-58
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• 2001

Sulfonated poly(phenylene sulfide) (SPPS) polymers were prepared by sulfonation of poly[methyl[4-(phenylthio) phenyl]sulfonium trifluoromethanesulfonate] (PPST) with fumic sulfonic acid (10% $SO_3-H_2SO_4$) and demethylation with aqueous NaOH solution. The equilibrium constants of ion exchange reactions between alkali metal cations ($Li^+,\;Na^+,\;and\;K^+$) and SPPS ion exchanger in organic solvents such as tetrahydrofuran (THF) and dioxane were measured. The equilibrium constants of ion exchange reactions increased as the polarity of the solvent increased, and the reaction temperature decreased. The equilibrium constants of the ion exchange reaction ($K_{eq}$) also increased in the order of $Li^+,\;Na^+,\;and\;K^+$. To elucidate the spontaneity of the exchange reaction in organic solvents, the enthalpy, entropy, and Gibbs free energy were calculated. The enthalpy of reaction ranged from -0.88 to -1.33 kcal/mol, entropy ranged from 1.42 to 4.41 cal/Kmol, and Gibbs free energy ranged from -1.03 to -2.55 kcal/mol. Therefore, the exchange reactions were spontaneous because the Gibbs free energies were negative. The SPPS ion exchanger and alkali metal ion bounding each other produced good ion exchange capability in organic solvents.

• Bulletin of the Korean Chemical Society
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• v.3 no.3
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• pp.119-122
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• 1982

Rigid ${\alpha}$-oximino ketones containing two functional groups such as 2-oximino-1-acenaphthenone and 2-oximino-1-indanone were synthesized and the simultaneous reduction of the two functional groups of ${\alpha}$-oximino ketones by $LiAlH_4$ gave the corresponding amino alcohols, 2-amino-1-acenaphthenol and 2-amino-1-indanol. The yields of the reduction products of the ${\alpha}$ -oximino ketones remarkably increased, as the increase of molar ratio of hydride used to the reactant. The use of 24 moles of $LiAlH_4$ was found to afford the best result in the reduction of the rigid ${\alpha}$-oximino ketones to the corresponding amino alcohols. The yields was not affected by the variation of solvents such as ether, THF and diglyme.

• Bulletin of the Korean Chemical Society
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• v.20 no.4
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• pp.422-426
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• 1999

The Grignard reactions of bis(chloromethyl)dimethylsilane (1) with trimethylchlorosilane (2) in THF give both the intermolecular C-Si coupling and intramolecular C-C coupling products. At beginning stage, 1 reacts with Mg to give the mono-Grignard reagent ClCH2Me2SiCH2MgCl (1) which undergoes the C-Si coupling reaction to give MC2Si(CH2SiMe3)2 3, or C-C coupling to a mixture of formula Me3SiCH2(SiMe2CH2CH2)nR1 (n = 1, 2, 3, ..; 4a, R1I = H: 4b, R1 = SiMe3). In the reaction, two reaction pathways are involved: a) Ⅰ reacts with 2 to give Me3SiCH2SiMe2CH2Cl 6 which further reacts with Mg to afford a Me2SiCH2Mel-SiCH2MgCl (Ⅱ) or b) I cyclizes intramolecularly to a silacyclopropane intermediate A, which undergoes a ring-opening polymerization by the nucleophilic attack of the intermediates I or Ⅱ, followed by the termination reaction with H2O and 2, to give 4a and 4b, respectively. As the mole ratio of 2/1 increased from 2 to 16 folds, the formation of product 3 increased from 16% to 47% while the formation of polymeric products 4 was reduced from 60% to 40%. The intermolecular C-Si coupling reaction of the pathway a becomes more favorable than the intramolecular C-C coupling reaction of the pathways b at the higher mole ratio of 2/1.

• Bulletin of the Korean Chemical Society
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• v.15 no.6
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• pp.432-436
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• 1994

Monomeric rhodium and iridium-diaryltetrazene complexes $Cp^*$M(RNN=NNR)($Cp^*$=1,2,3,4,5-pentamethylcyclope ntadienyl; M=Rh, Ir; R=Ph, 4-tolyl) have been synthesized from [$Cp^*MCl_2]_2$(M=Rh, Ir) and 2 equiv. of $[Li(THF)_x]_2(RN_4$R) in benzene. We have determined the crystal structure of (${\eta}^5$-pentamethylcyclopentadienyl)diphenyltetrazene iridium by using graphite-monochromated Mo-$K_a$ radiation. The compound was crystallized in the monoclinic space group $P2_{1/c}$ with a=13.781(3), b=9.035(l), c=17.699(3) ${\AA}$, and ${\beta}=111.93(l)^{\circ}$. An X-ray crystal structure of complex 1 showed a short N(2)-N(3) distance ($1.265 {\AA}$) consistent with the valence tautomer A with Ir(III) rather than Ir(I). All complexes are highly colored and decompose on irradiation at 254 nm. Electrochemical studies show that complex 1 displays a quasi-reversible reduction.

• 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).

• Bulletin of the Korean Chemical Society
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• v.19 no.11
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• pp.1211-1216
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• 1998

Bis(diethyldithiocarbamato)ioxomolybdenum(VI), cis-MoO2(S2CNEt2)2, 1, reacted with chlorotrimethylsilane (Me33SiCl) to give a seven-coordinate, pentagonal bipyramidal complex MoOC12(S2CN]Et2)2, 3, in which the oxo ligand is trans to the chloride ligand and the two chloride ligands are mutually cis. The monooxo molybdenum complex bis(diethyidithiocarbamato)oxomolybdenum(IV), MoO(S2CNEt2)2, 2, reacted with phenyl isocyanate (PhNCO) to give an Mo dimer MO2{μ-N(CONPh)Ph}(μ-NPh)(NPh)2(S2CNEt2)2, 4, which contains an Mo-Mo bond, two diethyldithiocarbamato ligands, two terminal imido (NPh) ligands, and two bridging hnido (NPh) ligands. One of the two bridging NPh ligands seemed to have been attacked by the electrophilic phenyl isocyanate carbon, which suggests that the bridging imido NPh ligand is more nucleophilic than the terminal one. Crystallographic data for 3: monoclinic space group P21/c, a=8.908(l) Å, b=17.509(3) Å, c=12.683(2) Å, β=110.15(1)°, Z=4, R(wR2)=0.0611(0.1385). Crystallographic data for 4-THF: orthorhombic space group P212121, a=17.932(4) Å, b=22.715(5) Å, c=11.802(3) Å, Z=4, R(wR2)=0.0585(0.1286).

• Bulletin of the Korean Chemical Society
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• v.20 no.5
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• pp.581-586
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• 1999

A series of polyethers containing the thiazole or oxazole subcyclic moiety have been synthesized. Reaction of 2-aryl-4-hydroxymethylthiazole with tetra- and pentaethylene glycol di-p-tosylate in THF provided corresponding α,ω-bis[2'-aryl-4'-methylthiazole]polyethylene glycol in good yields. Similar treatment of 2-phenyl-4-hydroxymethyloxazole 7 and 2-phenyl-5-hydroxymethyloxazole 8 with tetraethylene glycol di-p-tosylate yielded the corresponding 1,13-bis [2'-phenyl-4'-methyloxazole]tetraethylene glycol 16 and 1,13-bis[2'-phenyl-5'-methyloxazole]tetraethylene glycol 17 in 69 and 43% yields in respectively. The potentiometric properties of PVC-based ion selective membranes containing 66 wt% o-nitrophenyloctyl ether (NPOE) and 4 wt% polyethers 9-17 have been examined. The membranes containing thiazole and oxazole polyether derivatives exhibited high selectivity toward silver (I) ion. It was observed that the response slopes of the electrodes to silver ion vary with the length of polyether chain linking two thiazole subcyclic moiety. Potentiometric data suggest that the number of ether units, CH2OCH2, for phenylthiazole derivatives be greater than 5 to result in near-Nernstian response. However, the response behaviors of the membrane electrodes based on phenyloxazole podands 16 and 17, which have different orientation, were correspondingly similar to those of the electrodes based on phenylthiazole podands 9 and 10. On the other hand, the ISEs based on thiazole polyether derivatives with different terminal substituents, e.g., phenyl 10, naphtyl 14, and thienyl 15, except that with pyridyl 12, exhibited little difference in their potentiometric properties.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.257-260
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• 1987

The asymmetric reduction of representative prochiral ${\alpha},{\beta}$-acetylenic ketones with a new chiral borohydride reducing agent, potassium 9-0-(1,2: 5,6-Di-O-isopropylidene-${\alpha}$ -D-glucofuranosyl)-9-boratabicyclo[3.3.1]nonane, 1, in THF at $-78^{\circ}C$ was studied. Structurally different acetylenic ketones such as internal ${\alpha},{\beta}$-acetylenic ketones $RC {\equiv} CCOCH_3$ and terminal ${\alpha},{\beta}$-acetylenic ketones $HC {\equiv} CCOR$ were chosen. Thus, the reduction of internal ${\alpha},{\beta}$-acetylenic ketones yields the corresponding propargyl alcohols, such as 67% ee for 3-hexyn-2-one, 75% ee for 5-methyl-3-hexyn-2-one, 86% ee for 5,5-dimethyl-3-hexyn-2-one, 74% ee for 3-nonyn-2-one and 61% ee for 4-phenyl-3-butyn-2-one. Terminal ${\alpha},{\beta}$-acetylenic ketones, such as 3-butyn-2-one, 1-pentyn-3-one, 4-methyl-1-pentyn-3-one and 1-octyn-3-one, are reduced to the corresponding alcohols with 59% ee, 17% ee, 44% ee and 12% ee of optical induction respectively. With one exception (4-methyl-1-pentyn-3-one), all propargyl alcohols obtained are enriched in R-enantiomers.

• Bulletin of the Korean Chemical Society
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• v.18 no.3
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• pp.274-280
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• 1997

The rates and stoichiometry of the reaction of gallane-trimethylamine with selected organic compounds containing representative functional groups were examined in tetrahydrofuran solution under standardized conditions (THF, 0 ℃). And its reducing characteristics were compared with those of aluminum hydride-triethylamine(AHTEA). The rate of hydrogen evolution from active hydrogen compounds varied considerably with the nature of the functional group and the structure of the hydrocarbon moiety. Alcohols, phenol, amines, thiols evolved hydrogen rapidly and quantitatively. Aldehydes and ketones were reduced moderately to the corresponding alcohols. Cinnamaldehyde was reduced to cinnamyl alcohol, which means that the conjugated double bond was not attacked by gallane-trimethylamine. Carboxylic acids, esters, and lactones were stable to the reagent under standard conditions. Acid chlorides also were rapidly reduced to the corresponding alcohols. Epoxides and halides were inert to the reagent. Caproamide and nitrile were stable to the reagent, whereas benzamide was rapidly reduced to benzylamine. Nitropropane, nitrobenzene and azoxybenzene were stable to the reagent, whereas azobenzene was reduced to 1,2-diphenylhydrazine. Oximes and pyridine N-oxide were reduced rapidly. Di-n-butyl disulfide and dimethyl sulfoxide were reduced only slowly, but diphenyl disulfide was reduced rapidly. Finally, sulfones and sulfonic acids were inert to the reagent under the reaction.

• Journal of the Korean Chemical Society
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• v.30 no.5
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• pp.483-487
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• 1986

The synthesis of $\beta-damascone$ (I), an odoriferous natural product, was investigated from 2,2,6-trimethylcyclohexanone (II); (II) was ethynylated by the action of monoacetylide anion prepared from acetylene and sec-butyllithium at -78${\circ}C$, to give an ethynylcarbinol(III), which was isomerized to an acetylcyclohexene(IV) by refluxing in aqueous oxalic or formic acid. (IV) was treated with sec-butyllithium, the enolate was reacted with freshly dried acetaldehyde, and the resultant $\beta-hydroxyketone$ (V) was dehydrated by TsOH to ${\beta}$-damascone, trans-2,6,6-trimethyl-1-crotonyl-1-cyclohexene(I).