Effect of Cyclopentadienyl and Anionic Ancillary Ligand in Syndiospecific Styrene Polymerization Catalyzed by Nonbridged Half-Titanocenes Containing Aryloxo, Amide, and Anilide Ligands:  Cocatalyst Systems

2004 ◽  
Vol 37 (15) ◽  
pp. 5520-5530 ◽  
Author(s):  
Doo Jin Byun ◽  
Aya Fudo ◽  
Aki Tanaka ◽  
Michiya Fujiki ◽  
Kotohiro Nomura
Keyword(s):  
Ancillary Ligand ◽  
Styrene Polymerization

Ancillary Ligand Effect on Single-Site Styrene Polymerization:  Isospecificity of Group 4 Metal Bis(phenolate) Catalysts

2003 ◽  
Vol 125 (17) ◽  
pp. 4964-4965 ◽  
Author(s):  
Carmine Capacchione ◽  
Antonio Proto ◽  
Henner Ebeling ◽  
Rolf Mülhaupt ◽  
Klaus Möller ◽  
...  
Keyword(s):  
Single Site ◽  
Ancillary Ligand ◽  
Ligand Effect ◽  
Styrene Polymerization ◽  
Group 4 ◽  
Group 4 Metal

The Use of Styrenes as Embedding Media for Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 488-489
Author(s):  
Edward D. De-Lamater ◽  
Eric Johnson ◽  
Thad Schoen ◽  
Cecil Whitaker
Keyword(s):  
Electron Microscopy ◽  
Surface Tension ◽  
Ultraviolet Light ◽  
Methyl Ethyl Ketone Peroxide ◽  
Methyl Ethyl ◽  
Styrene Polymerization ◽  
Radical Initiation ◽  
Tertiary Butyl ◽  
Low Viscosity ◽  
Free Radical Initiation

Monomeric styrenes are demonstrated as excellent embedding media for electron microscopy. Monomeric styrene has extremely low viscosity and low surface tension (less than 1) affording extremely rapid penetration into the specimen. Spurr's Medium based on ERL-4206 (J.Ultra. Research 26, 31-43, 1969) is viscous, requiring gradual infiltration with increasing concentrations. Styrenes are soluble in alcohol and acetone thus fitting well into the usual dehydration procedures. Infiltration with styrene may be done directly following complete dehydration without dilution.Monomeric styrenes are usually inhibited from polymerization by a catechol, in this case, tertiary butyl catechol. Styrene polymerization is activated by Methyl Ethyl Ketone peroxide, a liquid, and probably acts by overcoming the inhibition of the catechol, acting as a source of free radical initiation.Polymerization is carried out either by a temperature of 60°C. or under ultraviolet light with wave lengths of 3400-4000 Engstroms; polymerization stops on removal from the ultraviolet light or heat and is therefore controlled by the length of exposure.

Imine as a Linchpin Approach for Distal C(sp2)–H Functionalization

2020 ◽  
Author(s):  
Sukdev Bag ◽  
Sadhan Jana ◽  
Sukumar Pradhan ◽  
Suman Bhowmick ◽  
Nupur Goswami ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Bond Activation ◽  
Bond Formation ◽  
Ancillary Ligand ◽  
Significant Challenge ◽  
Site Selectivity ◽  
Directing Group ◽  
Covalently Linked ◽  
Complex Organic ◽  
Post Functionalization

<p>Despite the widespread applications of C–H functionalization, controlling site selectivity remains a significant challenge. Covalently attached directing group (DG) served as an ancillary ligand to ensure proximal <i>ortho</i>-, distal <i>meta</i>- and <i>para</i>-C-H functionalization over the last two decades. These covalently linked DGs necessitate two extra steps for a single C–H functionalization: introduction of DG prior to C–H activation and removal of DG post-functionalization. We introduce here a transient directing group for distal C(<i>sp<sup>2</sup></i>)-H functionalization <i>via</i> reversible imine formation. By overruling facile proximal C-H bond activation by imine-<i>N</i> atom, a suitably designed pyrimidine-based transient directing group (TDG) successfully delivered selective distal C-C bond formation. Application of this transient directing group strategy for streamlining the synthesis of complex organic molecules without any necessary pre-functionalization at the distal position has been explored.</p>

Copper(I)−Olefin Complexes: The Effect of the Trispyrazolylborate Ancillary Ligand in Structure and Reactivity

2010 ◽  
Vol 29 (16) ◽  
pp. 3481-3489 ◽  
Author(s):  
Carmen Martín ◽  
José María Muñoz-Molina ◽  
Abel Locati ◽  
Eleuterio Alvarez ◽  
Feliu Maseras ◽  
...  
Keyword(s):  
Ancillary Ligand

Organosilane Effects on Organotitanium-Catalyzed Styrene Polymerization

2007 ◽  
Vol 26 (12) ◽  
pp. 2960-2963 ◽  
Author(s):  
Smruti B. Amin ◽  
Tobin J. Marks
Keyword(s):  
Styrene Polymerization

(ArO)TiR3 complexes for highly syndiospecific styrene polymerization

2014 ◽  
Vol 383-384 ◽  
pp. 77-82 ◽  
Author(s):  
Chongjie Xu ◽  
Zhou Chen ◽  
Gang Ji ◽  
Xiu-Li Sun ◽  
Jun-Fang Li ◽  
...  
Keyword(s):  
Styrene Polymerization
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