http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Bijal Kottukkal Bahuleyan,안인용,Vinukrishnan Appukuttan,이소현,하창식,김일,서홍석 한국고분자학회 2010 Macromolecular Research Vol.18 No.7
A series of tridentate cobalt complexes of the general formula [RN(CH2)2N]=An=[N(2,6-C6H3iPr)](R=Me, Et, iPr; An=acenaphthenequinone) have been synthesized. All complexes were active towards ethylene oligomerization,showing activities exceeding 104 g-oligomer/mol-Co·h·bar in the presence of a methylaluminoxane co-catalyst. 1-Butene and trans-2-hexene were the major oligomer fractions obtained.
Ethylene polymerization by sterically and electronically modulated Ni(II) α-diimine complexes
Bahuleyan, Bijal Kottukkal,Son, Gi Wan,Park, Dae-Won,Ha, Chang-Sik,Kim, Il Wiley Subscription Services, Inc., A Wiley Company 2008 Journal of polymer science Part A, Polymer chemist Vol.46 No.3
<P>A series of highly active ethylene polymerization catalysts based on bidendate α-diimine ligands coordinated to nickel are reported. The ligands are prepared via the condensation of bulky ortho-substituted anilines bearing remote push–pull substituents with acenaphthenequinone, and the precatalysts are prepared via coordination of these ligands to (DME)NiBr<SUB>2</SUB> (DME = 1,2-dimethoxyethane) to form complexes having general formula [ZN = C(An)-C(An) = NZ]NiBr<SUB>2</SUB> [Z = (4-NH<SUB>2</SUB>-3,5-C<SUB>6</SUB>H<SUB>2</SUB>R<SUB>2</SUB>)<SUB>2</SUB>CH(4-C<SUB>6</SUB>H<SUB>4</SUB>Y); An, acenaphthene quinone; R, Me, Et, iPr; Y = H, NO<SUB>2</SUB>, OCH<SUB>3</SUB>]. When activated with methylaluminoxane (MAO) or common alkyl aluminiums such as ethyl aluminium sesquichloride (EAS) all catalysts polymerize ethylene with activities exceeding 10<SUP>7</SUP> g-PE/ mol-Ni h atm at 30 °C and atmospheric pressure. Among the cocatalysts used EAS records the best activity. Effects of remote substituents on ethylene polymerization activity are also investigated. The change in potential of metal center induced by remote substituents, as evidenced by cyclic voltammetric measurements, influences the polymerization activity. UV–visible spectroscopic data have specified the important role of cocatalyst in the stabilization of nickel-based active species. A tentative interpretation based on the formation of active and dormant species has been discussed. The resulting polyethylene was characterized by high molecular weight and relatively broad molecular weight distribution, and their microstructure varied with the structure of catalyst and cocatalyst. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1066–1082, 2008</P> <B>Graphic Abstract</B> <P>Highly active ethylene polymerization catalysts based on bidendate α-diimine ligands coordinated to nickel having general formula [ZN = C(An)-C(An) = NZ] NiBr<SUB>2</SUB> [Z = (4-NH<SUB>2</SUB>-3,5-C<SUB>6</SUB>H<SUB>2</SUB>R<SUB>2</SUB>)<SUB>2</SUB>CH(4-C<SUB>6</SUB>H<SUB>4</SUB>Y); An, acenaphthene quinone; R, Me, Et, iPr; Y = H, NO<SUB>2</SUB>, OCH<SUB>3</SUB>] are reported. Among the cocatalysts used ethyl aluminium sesquichloride (EAS) records the best activity exceeding 10<SUP>7</SUP> g-PE/ mol-Ni h atm at 30 C and atmospheric pressure. Effects of remote substituents on ethylene polymerization activity are also investigated. Polyethylene was characterized by high molecular weight and relatively broad molecular weight distribution and their microstructure varied with the structure of catalyst and cocatalyst. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.] <img src='wiley_img/0887624X-2008-46-3-POLA22450-gra001.gif' alt='wiley_img/0887624X-2008-46-3-POLA22450-gra001'> </P>
Bahuleyan, Bijal Kottukkal,Son, Bong Chul,Ha, Yun Son,Lee, So Hyun,Suh, Hongsuk,Kim, Il Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.34
<P>Adopting a leaching- and fragmentation-free protocol, Ni(<SMALL>II</SMALL>) α-diimine complexes were covalently anchored on nonporous silica without any conventional tedious process. The supported catalysts polymerized ethylene with activities > 10<SUP>6</SUP> g-PE mol-Ni<SUP>−1</SUP> h<SUP>−1</SUP> bar<SUP>−1</SUP> (10 kg-PE g-cat<SUP>−1</SUP> at 5.5 bar pressure) when activated with a small amount (Al/Ni ∼100) of common aluminium alkyls (ethylaluminium sesquichloride, methylaluminium dichloride, and diethylaluminium chloride) in the absence of any methylaluminoxane. The polymer growth pattern from uniform spheres to fibers was clearly traced by using this model supported system, which depends on the catalytic activity, metal loading, and effective selection of co-catalysts. The polymerization results were compared with conventional porous silica supports immobilized by the same complex that undergoes fragmentation leading to a poor PE morphology.</P> <P>Graphic Abstract</P><P>A leaching- and fragmentation-free protocol is developed to immobilize the late transition metal catalysts and polymer growth mechanism is illustrated. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0jm01290d'> </P>