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	<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
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		<title>Sonoluminescence from OH(C2Σ+) and OH(A2Σ+) Radicals in Water: Evidence for Plasma Formation during Multibubble Cavitation</title>
		<link>http://w-tungsten.info/archives/1571</link>
		<comments>http://w-tungsten.info/archives/1571#comments</comments>
		<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
		<dc:creator>Rachel Pflieger</dc:creator>
		
		<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">doi:10.1002/chem.201002170</guid>
		<description><![CDATA[Bubble trouble: Multibubble sonoluminescence spectra in water under Kr and Xe present emission lines of OH(C2Σ+–A2Σ+) (see graphic). This band, never observed in flames, indicates plasma formation in the collapsing bubbles.]]></description>
		<wfw:commentRss>http://w-tungsten.info/archives/1571/feed</wfw:commentRss>
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		<title>Hierarchical Hollow Co9S8 Microspheres: Solvothermal Synthesis, Magnetic, Electrochemical, and Electrocatalytic Properties</title>
		<link>http://w-tungsten.info/archives/1570</link>
		<comments>http://w-tungsten.info/archives/1570#comments</comments>
		<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
		<dc:creator>Yu-Xue Zhou</dc:creator>
		
		<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">doi:10.1002/chem.200903263</guid>
		<description><![CDATA[A simple solvothermal route in a binary solution of triethylenetetramine (TETA) and deionized water (DIW) has been used to synthesize hierarchical hollow Co9S8 microspheres with high surface area (80.38 m2 g−1). An appropriate volume ratio of TETA:DIW has been found to be essential for the formation of hollow Co9S8 microspheres. The magnetic study indicated that the Co9S8 hollow microspheres are paramagnetic at high temperature and antiferromagnetic at low temperature. The oxygen reduction reaction experiments demonstrated that the onset potential of the Co9S8 sample is 0.88 V, which is comparable to the value predicted for Co9S8 (0.74 V) from the theoretical simulation. The discharge capability of Co9S8 hollow microspheres as cathode materials for lithium ion batteries and their electrocatalytic activity for the oxygen reduction reaction (ORR) have been studied.Cathode materials: Hierarchical hollow Co9S8 microspheres (shown here) can be synthesized by a simple solvothermal route in a binary solution of triethylenetetramine and deionized water. The onset potential of Co9S8 hollow spheres is 0.88 V for the oxygen reduction reaction. The magnetic properties of Co9S8 hollow microspheres and their use as cathode materials for lithium ion cells have been studied.]]></description>
		<wfw:commentRss>http://w-tungsten.info/archives/1570/feed</wfw:commentRss>
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		<item>
		<title>Localized Deposition of Au Nanoparticles by Direct Electron Transfer through Cellobiose Dehydrogenase</title>
		<link>http://w-tungsten.info/archives/1569</link>
		<comments>http://w-tungsten.info/archives/1569#comments</comments>
		<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
		<dc:creator>Esteban Malel</dc:creator>
		
		<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">doi:10.1002/chem.201000453</guid>
		<description><![CDATA[Cellobiose dehydrogenase (CDH) is a fascinating extracellular fungal enzyme that consists of two domains, one carrying a flavin adenine dinucleotide (FAD) and the other a cytochrome-type heme b group as cofactors. The two domains are interconnected by a linker and electrons can shuttle from the FAD to the heme group by intramolecular electron transfer. Electron transfer between CDH and an electrode can occur by direct electron transfer (DET) and by mediated electron transfer (MET). This characteristic makes CDH an interesting candidate for integration in systems such as biosensors and biofuel cells. Moreover, it makes CDH an alternative for the reduction of metal ions through DET and MET. In this work we have explored the localized deposition of gold on Pd substrates by CDH through DET and MET. For this purpose we exploited the advantage of scanning electrochemical microscopy (SECM) as a patterning tool. We first demonstrated that gold nanoparticles can be formed in homogenous solution. Then we showed that Au nanoparticles can also be locally formed and deposited on surfaces through DET at low pH and by MET at neutral pH using benzoquinone/hydroquinone as mediator.Biocatalytic deposition of gold nanoparticles was achieved by scanning electrochemical microscopy. A gold ultra-micro-electrode (UME) acts as a source of gold ions that are reduced by direct electron transfer from the enzyme cellobiose dehydrogenase (CDH) in the presence of β-D-lactose and deposited on a catalytic substrate such as palladium (see scheme).]]></description>
		<wfw:commentRss>http://w-tungsten.info/archives/1569/feed</wfw:commentRss>
		</item>
		<item>
		<title>Electronic Tuning of a Carbene Center via Remote Chemical Induction, and Relevant Effects in Catalysis</title>
		<link>http://w-tungsten.info/archives/1568</link>
		<comments>http://w-tungsten.info/archives/1568#comments</comments>
		<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
		<dc:creator>Vincent César</dc:creator>
		
		<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">doi:10.1002/chem.201000870</guid>
		<description><![CDATA[The present report develops the idea that an N-heterocyclic carbene incorporating a remote anionic functionality—here, a malonate group—as a backbone component of its heterocyclic framework, can be “post-functionalized” directly from its transition-metal complexes, upon simple addition of a variety of electrophiles interacting directly with the malonate group in the outer coordination sphere. From a palette of selected electrophilic reagents, it was thus possible to modulate the electronic donor properties of the carbene center over a rather broad range. Both the zwitterionic complex [Rh{malo-NHC}(cod)] and the cationic derivatives [Rh{malo-NHCE}(cod)]+ (where “malo-NHCE” represents the ligand modified by a selected electrophile “E”) were used as pre-catalysts in two types of catalytic reactions, namely, the polymerization of phenylacetylene and the hydroboration of styrene. The results indicate that, in both cases, the zwitterionic species is by far the best catalyst, whereas a decrease in the ligand donicity induced by the added electrophile results in a concomitant reduction of catalytic activity. Apparent deviations to such a trend in the case of the hydroboration of styrene were rationalized in terms of an interaction between the reactive catecholborane substrate and the remote functionality of the N-heterocyclic carbene leading to an in situ modification of the nature of the active species. These observations serve as a useful basis to define the scope and limitations of the present conceptual approach in catalysis.The right tone: The donor properties of a metal-bound NHC ligand possessing a malonate backbone can be finely tuned by simple addition of a selected electrophile interacting with the remote nucleophilic part of the ligand in the outer coordination sphere of the complex. Relevant consequences on the catalytic behavior of these species were observed and rationalized on the basis of two test catalytic reactions.]]></description>
		<wfw:commentRss>http://w-tungsten.info/archives/1568/feed</wfw:commentRss>
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		<item>
		<title>Getting Ring-Closing Metathesis off the Bench: Reaction-Reactor Matching Transforms Metathesis Efficiency in the Assembly of Large Rings</title>
		<link>http://w-tungsten.info/archives/1567</link>
		<comments>http://w-tungsten.info/archives/1567#comments</comments>
		<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
		<dc:creator>Sebastien Monfette</dc:creator>
		
		<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">doi:10.1002/chem.201001210</guid>
		<description><![CDATA[Reported is the first study of the influence of reactor configuration on the efficiency of a challenging ring-closing metathesis (RCM) reaction. With the intention of increasing the generality of RCM scaleup and reducing its dependence on substrate modification, macrocyclization of an unmodified, low effective-molarity diene was explored using different reactor types, in conjunction with a commercial, homogeneous Grubbs catalyst. Optimized performance is compared for a conventional batch reactor (BR), a continuous plug-flow reactor (PFR), and a continuous stirred-tank reactor (CSTR). In the PFR, maximum conversion is achieved most rapidly, but product yields and selectivity are adversely affected by co-entrapment of ethylene with the catalyst, substrate, and product in the traveling “plug”. Use of the CSTR, in which ethylene is efficiently swept out, affords an order-of-magnitude increase in total turnover numbers, and reduces the required catalyst loadings by 25× relative to the BR (to 0.2 mol %), while improving RCM yields and selectivity to quantitative levels. Continuous-flow methodologies that support liberation of the ethylene co-product thus show great promise for industrial uptake of RCM.Go with the flow: Remarkably efficient ring-closing metathesis (RCM) macrocyclization is achieved by judicious matching of reaction and reactor. In a comparative study of batch, plug-flow, and continuous stirred-tank reactors, the last example enabled significantly higher yields and selectivity, in shorter reaction times, by using 25× less catalyst (0.2 mol %) than the conventional batch reaction.]]></description>
		<wfw:commentRss>http://w-tungsten.info/archives/1567/feed</wfw:commentRss>
		</item>
		<item>
		<title>Electronic and Optical Properties in the Solid-State Molecular Assemblies of Anion-Responsive Pyrrole-Based π-Conjugated Systems</title>
		<link>http://w-tungsten.info/archives/1566</link>
		<comments>http://w-tungsten.info/archives/1566#comments</comments>
		<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
		<dc:creator>Hiromitsu Maeda</dc:creator>
		
		<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">doi:10.1002/chem.201001852</guid>
		<description><![CDATA[On the basis of the chemistry in solution, the solid-state structures and the corresponding electronic and optical properties of dipyrrolyldiketone boron complexes as π-conjugated acyclic anion receptors have been investigated. Solid-state assemblies of the receptors exhibit anion-dependent properties that are in sharp contrast to those in the solution state. Anion complexation, along with structural differences in the pyrrole subunits such as a benzo-fused pyrrole, plays an essential role not only in the formation of the assembled modes but also in determining electronic and optical properties, as well as the charge-carrier mobilities. In addition, by anion complexation, inclusion of the counter cations into the crystals has also been found to be one of the essential factors to determine the properties.Any old (an)ion? Solid-state assemblies of π-conjugated acyclic anion receptors exhibit anion-dependent properties that are in sharp contrast to those in the solution state. Anion complexation, along with structural differences in the pyrrole subunits, such as a benzo-fused pyrrole, plays an essential role not only in the formation of the assembled modes, but also in determining the electronic and optical properties, as well as the charge-carrier mobilities (see graphic).]]></description>
		<wfw:commentRss>http://w-tungsten.info/archives/1566/feed</wfw:commentRss>
		</item>
		<item>
		<title>Dendrimer-Induced Molecular Catalysis in Water: The Example of Olefin Metathesis</title>
		<link>http://w-tungsten.info/archives/1565</link>
		<comments>http://w-tungsten.info/archives/1565#comments</comments>
		<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
		<dc:creator>Abdou K. Diallo</dc:creator>
		
		<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">doi:10.1002/chem.201002014</guid>
		<description><![CDATA[A dendritic nanoreactor (see graphic) constructed by 1→3 connectivity and terminated by 27 tetraethyleneglycol tethers induces ring-closing metathesis (RCM), cross metathesis (CM) and enyne metathesis (EYM) using low amounts of Grubbs-II catalyst in water and air, down to 0.04 % Grubbs catalyst for RCM. The dendrimer can be re-used at least 10 times without significant yield decrease.]]></description>
		<wfw:commentRss>http://w-tungsten.info/archives/1565/feed</wfw:commentRss>
		</item>
		<item>
		<title>Dramatic Impact of ppb Levels of Palladium on the “Copper-Catalyzed” Sonogashira Coupling</title>
		<link>http://w-tungsten.info/archives/1564</link>
		<comments>http://w-tungsten.info/archives/1564#comments</comments>
		<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
		<dc:creator>Zsombor Gonda</dc:creator>
		
		<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">doi:10.1002/chem.201001880</guid>
		<description><![CDATA[Palladacadabra! The effect of ppb levels of palladium on the “copper-catalyzed” Sonogashira coupling is reported. The observed high sensitivity to palladium impurities queries the existence of pure copper catalysis in the coupling of aryl iodides and terminal acetylenes (see figure).]]></description>
		<wfw:commentRss>http://w-tungsten.info/archives/1564/feed</wfw:commentRss>
		</item>
		<item>
		<title>Synthesis and Structures of Multifunctionalized Helicenes and Dehydrohelicenes: An Efficient Route to Construct Cyan Fluorescent Molecules</title>
		<link>http://w-tungsten.info/archives/1563</link>
		<comments>http://w-tungsten.info/archives/1563#comments</comments>
		<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
		<dc:creator>Jun-Dao Chen</dc:creator>
		
		<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">doi:10.1002/chem.201001655</guid>
		<description><![CDATA[Spiral up! A series of multifunctionalized benzo[5]helicene derivatives and a benzo[7]helicene were conveniently synthesized. Moreover, the oxidative cyclodehydrogenation of the benzo[5]helicenes by DDQ in trifluoroacetic acid or trifluoromethanesulfonic acid quantitatively provided the corresponding dehydro[5]helicene derivatives, which showed the cyan fluorescent properties (shown here).]]></description>
		<wfw:commentRss>http://w-tungsten.info/archives/1563/feed</wfw:commentRss>
		</item>
		<item>
		<title>Room-Temperature Deoxygenation of Epoxides with CO Catalyzed by Hydrotalcite-Supported Gold Nanoparticles in Water</title>
		<link>http://w-tungsten.info/archives/1562</link>
		<comments>http://w-tungsten.info/archives/1562#comments</comments>
		<pubDate>Mon, 06 Sep 2010 05:00:00 +0000</pubDate>
		<dc:creator>Takato Mitsudome</dc:creator>
		
		<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">doi:10.1002/chem.201001387</guid>
		<description><![CDATA[Epoxide deoxygenation: Hydrotalcite-supported gold nanoparticles (Au/HT) efficiently catalyze the deoxygenation of epoxides to alkenes in water at room temperature under CO at atmospheric pressure and in the absence of organic solvents (see graphic). Moreover, Au/HT retains its activity and selectivity and can be reused.]]></description>
		<wfw:commentRss>http://w-tungsten.info/archives/1562/feed</wfw:commentRss>
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