• Bulletin of the Korean Chemical Society
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• 제25권11호
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• pp.1648-1652
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• 2004

A set of unprecedented syndiospecific dimethyl- and diethylamino-functionalized polystyrenes was prepared by catalytically polymerizing the corresponding monomers using (pentamethylcyclopentadienyl)titanatrane/MMAO catalytic system. Dialkylamino-functionalized styrene monomers were synthesized by Wittig reaction from the corresponding aldehyde in high yield. The resulting polymers are soluble in polar organic solvents such as THF and show good thermal stability. The chemical transformation of the syndiospecific poly(4-diethylaminostyrene) also gave new polar polymers, namely syndiotactic poly(4-diethylaminostyrene hydrochloride), which is unattainable by traditional synthetic methods.

• Bulletin of the Korean Chemical Society
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• 제15권6호
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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.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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• pp.27-27
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• 2002

[Cp＊Rh(H₂O)₃](OTf)₂ (1) reacts with a stoichiometric amount of A and B [ A = Me₃SiN₃, B = 4,4'-bipridyl, (2a), A = Me₃SiNCO, B = 4,4'-bipridyl (2b)] in acetone at room temperature for 3 h to give the supramolecular complexes [Cp＊₄Rh₄(μ-A)₄(μ-B)₂] [A = Me₃SiN₃, B = 4,4'-bipridyl, (2a), A = Me₃SiNCO, B = 4,4'-bipridyl (2b)]. Complexes 2a and 2b have been structurally characterized by X-ray diffraction.

• Bulletin of the Korean Chemical Society
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• 제26권10호
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• pp.1620-1622
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• 2005

• Macromolecular Research
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• 제15권1호
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• pp.31-38
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• 2007

Pentamethylcyclopentadienyltitanium trichloride, bis(cyclopentadienyl)titanium dichloride ($Cp_2TiCl_2$), and bis(pentamethylcyclopentadienyl)titanium dichloride were used in the polymerization of styrene without the aid of Group I-III cocatalysts. The properties of the resulting polymer indicated that polymerization was more controlled than in thermal polymerization. The kinetic studies indicated that a lower level of termination is present and that the polymer chain can be extended by adding an additional monomer. To elucidate the mechanism of polymerization, a series of experiments was performed. All results supported the involvement of a radical mechanism in the polymerization using $Cp_2TiCl_2$. The possibility of atom transfer radical polymerization (ATRP) mechanism was investigated by isolating the intermediate species. We could confirm the activation step from the reaction of 1-PEC1 with $Cp_2TiCl$ by detecting the coupling product of the generated active radicals. However, the reversible deactivation reaction competes with other side reactions, and it detection was difficult with our model system.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.226-226
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• 2006

Ethylene was polymerized with a catalyst having sterically hindered pentamethylcyclopentadienyl ligand, $Cp^{\ast}_{2}ZrCl_{2}/MAO$, and the polymerization mixture were treated with dry oxygen (oxidative workup) to produce hydroxyl-terminated polyethylenes (PE-OH). Polyethylene-block-Poly (${\Box}-caprolactone$) was synthesized from PE-OH and ${\cdot}\^{A}-caprolactone$A by using stannous octoate as a catalyst for ring opening polymerization of ${\cdot}\^{A}-caprolactone$. Polyethylene-block-Poly(methyl methacrylate) was obtained by transforming the hydroxyl-terminated polyethylenes to macroinitiators for atom transfer radical polymerization (ATRP) and by reacting them with MMA.

• Bulletin of the Korean Chemical Society
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• 제15권11호
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• pp.980-984
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• 1994

Monomeric rhodium and iridium diimine complexes $Cp^*M(HNRNH)(Cp^*$ = 1,2,3,4,5-pentamethylcyclopentadienyl : (M=lr; R=o-$C_6H_4 (1a), 4,5-(CH_3)_2-C_6H_2-1,2 (1b), 4,5-(Cl)_2-C_6H_2-1,2$ (1c), NCC=CCN-1,2 (1d): M=Rh; R=NCC=CCN-1,2 (1e)) have been synthesized from $[CP^*MCl_2]_2$ and 2 equiv. of diamine in the presence of $NEt_3$. The Crystal structure of 1a was determined by X-ray diffraction method : 1a was crystallized in the monoclinic system, space group $P2_{1/c}$, with lattice constants a=9.543 (1) ${\AA}$, b=16.286 (1) ${\AA}$, c=10.068 (1) ${\AA}$ and ${\beta}$=99.25 (1), with Z= 4. Least-squares refinement of the structure led to R factor of 0.049. The coordination sphere of rhodium and iridium can be described as a 2-legged piano-stool. All complexes are highly colored. Electrochemical studies show that 1d and 1e display quasi-reversible reduction and 1a-1c display irreversible reductions, suggesting that the acceptor orbital might be localized on the diimine ring.

• 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.

• 분석과학
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• 제11권1호
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• pp.42-46
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• 1998

고리화펜타디엔이 ${\pi}$-결합된 최초의 비스무트 화합물$({\eta}^5-C_5Me_5)_2BiCl$이 에데르 용매하에서 칼륨펜타메틸고리화펜타다이엔과 삼염화비스무트의 반응결과 짙은 보라색의 결정이 30%의 수율로 얻어졌다. 이 화합물의 분해 생성물로서 pentamethylcyclopentadienylbismuth chloride($PCpBiCl_2$)가 얻어졌으며 $({\eta}^5-C_5Me_5)_2BiCl$은 칼륨펜타메틸고리화펜타다이엔과 $-78^{\circ}C$에서 반응하지 않음을 확인하였다. $({\eta}^5-C_5Me_5)_2BiCl$의 구조가 192K에서 X선 단결정 구조분석 방법에 의해 밝혀졌다: triclinic crystal, space group p1, Z=2. $C_{20}H_{30}$의 이탈반응이 확인되었으며 고리화펜타다이엔의 두 고리가 C-C ${\sigma}$-단일 결합으로 이루어져 있다는 것이 X선 단결정 구조분석 방법에 의해 밝혀졌다.