9,9-Disubstituted fluorenes are widely employed in materials science. We have developed a straightforward approach for the synthesis of 9,9-disubstituted fluorenes from 2-iodobiphenyls and α-diazoesters. The reaction proceeds via a tandem palladium-catalyzed C(sp2)–H activation/carbenoidinsertion sequence.
Novel long-chain dialkyl fluorene-9,9-dicarboxylates were synthesized by treating fluorene with lithium diisopropylamide followed by alkyl chloroformates. The fluorene derivatives were readily electro-oxidized to form electroactive films on the Surface of a glassy carbon electrode. From the viewpoint of suitable potential window (from -2.5 to 1.5 V vs Ag/Ag+), cyclic voltammograms of the films indicated the electroactive properties of the fluorene derivatives that make them good candidates for electrochemical capacitor materials. (C) 2009 Elsevier Ltd. All rights reserved.
OLEFIN POLYMERIZATION CATALYST CARRIER, SOLID CATALYST COMPONENT AND USE THEREOF
申请人:Renqiu Lihe Technology Ltd.
公开号:US20170355792A1
公开(公告)日:2017-12-14
Provided is an olefin polymerization catalyst carrier with a general structure formula of Mg(OR
I
)
n
(OR
II
)
2-n
, wherein: 0≦n≦2, and R
I
and R
II
can be the same or different and are each independently selected from a C
1
-C
20
hydrocarbon group. In the X-ray diffraction pattern of the catalyst carrier, there are a set of diffraction peaks in the range of a 2θ diffraction angle of 5°-15°, and the set of diffraction peaks contain 1-4 main diffraction peaks. Also disclosed is an olefin polymerization solid catalyst component which is prepared from the carrier Mg(OR
I
)
n
(OR
II
)
2-n
, a titanium compound, and at least one electron donor compound. In addition, also disclosed is an olefin polymerization catalyst containing the solid catalyst component, at least one organic aluminum compound, and optionally, an external electron donor compound.