A water-soluble boronate-based fluorescent probe was evaluated for the detection of peroxynitrite (ONOO−) in presence a monosaccharide. The enhanced fluorescence when bound with D-fructose switched off peroxynitrite. In contrast, other reactive oxygen/nitrogen species (ROS/RNS) led to only slight decreases due protection by an internal N–B interaction. interaction not strengthens signal, but also protects boronic acid from oxidation ROS/RNS. Therefore, under conditions generating various...

The series solution method developed by Pekeris for the Schrödinger wave equation of two-electron atoms has been generalized to handle any three particles with Coulomb interaction. Calculations have carried out wavefunctions through sixth degree which result in a linear combination 84 terms unsymmetrical case. Systems numerical results are given are: hydride ion nuclear motion, trielectron (e+e—e—) or positronium ion, positron—hydrogen atom interaction (e+e—p+), and mu-mesonic isotopic...

We report a series of Zr(<sc>iv</sc>) 2,2′-bipyrrolidine–salan derived complexes and their exploitation for the ROP <italic>rac</italic>-lactide to afford highly isotactically enriched PLA.

FlowNMR spectroscopy is an excellent technique for non-invasive real-time reaction monitoring under relevant conditions that avoids many of the limitations bedevil other techniques.

A series complexes based on 2,2′-bipyrrolidine salan ligands have been prepared and either isotactic or heterotactic PLA prepared.

Abstract Poly(mandelic acid) (PMA) is an aryl analogue of poly(lactic (PLA) and a biodegradable polystyrene. The preparation stereoregular PMA was realized using pyridine/mandelic acid adduct (Py⋅MA) as organocatalyst for the ring‐opening polymerization (ROP) cyclic O ‐carboxyanhydride ( man OCA). Polymers with narrow polydispersity index excellent molecular‐weight control were prepared at ambient temperature. These highly isotactic chiral polymers exhibit enhancement glass‐transition...

Abstract Reaction between a β‐diketiminato magnesium hydride and carbon monoxide results in the isolation of dimeric cis ‐enediolate species through reductive coupling two CO molecules. Under catalytic conditions with PhSiH 3 , an observable formyl may be intercepted for mild cleavage triple bond.

Reaction of [Ru(IPr)2(CO)H]BAr(F)4 with ZnEt2 forms the heterobimetallic species [Ru(IPr)2(CO)ZnEt]BAr(F)4 (2), which features an unsupported Ru-Zn bond. 2 reacts H2 to give [Ru(IPr)2(CO)(η(2)-H2)(H)2ZnEt]BAr(F)4 (3) and [Ru(IPr)2(CO)(H)2ZnEt]BAr(F)4 (4). DFT calculations indicate that activation at proceeds via oxidative cleavage Ru concomitant hydride transfer Zn. can also activate hydridic E-H bonds (E = B, Si), computed mechanisms for facile H/H exchange processes observed in 3 4 are presented.

Catalytic hydrogen transfer from basic isopropyl alcohol to aryl ketones mediated by [(arene)(TsDPEN)RuCl] complexes has been investigated operando 1H NMR spectroscopy using a recirculating flow setup. Selective excitation pulse sequences allowed fast and quantitative monitoring of the key [(mesitylene)(TsDPEN)RuH] intermediate during catalysis, which is shown interact with both substrates polarization experiments. Comparison reaction profiles catalyst speciation traces in conjunction...

The catalytic addition of phosphines to alkenes and alkynes is a very attractive process that offers access in 100% atom-economic reaction using readily available inexpensive materials. products are potentially useful ligands organocatalysts. Herein, we report the first example intramolecular hydrophosphination series nonactivated phosphinoalkenes phosphinoalkynes with simple iron β-diketiminate complex. Kinetic studies suggest this transformation first-order respect both phosphine catalyst....

Reaction of [Ru(PPh3)3HCl] with LiCH2TMS, MgMe2, and ZnMe2 proceeds chloride abstraction alkane elimination to form the bis-cyclometalated derivatives [Ru(PPh3)(C6H4PPh2)2H][M'] where [M'] = [Li(THF)2]+ (1), [MgMe(THF)2]+ (3), [ZnMe]+ (4), respectively. In presence 12-crown-4, reaction LiCH2TMS yields [Ru(PPh3)(C6H4PPh2)2H][Li(12-crown-4)2] (2). These four complexes demonstrate increasing interaction between M' hydride ligand in [Ru(PPh3)(C6H4PPh2)2H]- anion following trend 2 (no...

Noyori-Ikariya type [(arene)RuCl(TsDPEN)] (TsDPEN, sulfonated diphenyl ethylenediamine) complexes are widely used C=O and C=N reduction catalysts that produce chiral alcohols amines via a key ruthenium-hydride intermediate determines the stereochemistry of product. Whereas many details about interactions pro-chiral substrate with hydride complex nature hydrogen transfer from latter to former have been investigated over past 25 years, role stereochemical configuration at stereogenic ruthenium...

Graphitic carbon nitride (g-C3N4) is known to photogenerate hydrogen peroxide in the presence of hole quenchers aqueous environments. Here, g-C3N4 photocatalyst embedded into a host polymer intrinsic microporosity (PIM-1) provide recoverable heterogenized photocatalysts without loss activity. Different types (including Pt@g-C3N4, Pd@g-C3N4, and Au@g-C3N4) different are investigated. Exploratory experiments yield data that suggest binding quencher either (i) directly by adsorption onto (as...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPredicting carcinogenicity of polycyclic aromatic hydrocarbonsJohn P. Lowe and B. David SilvermanCite this: Acc. Chem. Res. 1984, 17, 9, 332–338Publication Date (Print):September 1, 1984Publication History Published online1 May 2002Published inissue 1 September 1984https://pubs.acs.org/doi/10.1021/ar00105a006https://doi.org/10.1021/ar00105a006research-articleACS PublicationsRequest reuse permissionsArticle Views210Altmetric-Citations58LEARN ABOUT...

The internal rotation barrier in ethane appears susceptible to "explanation" at a qualitative, intuitively useful, reasonably correct level. At this level, localized and delocalized MO's each produce description. For rigid rotation, the description is basically "orbital control" type familiar from Woodward-Hoffmann rules, Walsh's formation of diatomic molecules. This indicates that long-range eclipsed H---H antibonding responsible for barrier. equivalent localized-bond invokes destructive...

A semiempirical electrostatic model for internal rotation in certain molecules is developed from the integral Hellmann—Feynman theorem. The shown to be capable of rationalizing and predicting barriers terms well-established physical chemical concepts. For simple hydrides containing only atoms first two rows periodic table (CH3NH2, CH3SH, etc.), methyl are correlated with electronegativity heavy atom (N,S, etc.). Effects due d f character bond hybrids appear important Rows III IV table....

We demonstrate how FlowNMR spectroscopy can readily be applied to investigate photochemical reactions that require sustained input of light and air yield mechanistic insight under realistic conditions. The Eosin Y mediated photo-oxidation N-allylbenzylamine is shown produce imines as primary reaction products from which undesired aldehydes form after longer times. Facile variation conditions during the in flow allows for probe experiments give information about mode action photocatalyst.

A range of N-heterocyclic carbene-supported copper diphenylphosphides (NHC = IPr, 6-Dipp, SIMes and 6-Mes) were synthesised. These include the first reports ring-expanded NHC-copper(i) phosphides. The compounds characterised by NMR spectroscopy X-ray crystallography. Reaction (6-Dipp)CuPPh2 with isocyanates, isothiocyanates carbon disulfide results in insertion heterocumulene into Cu-P bond. NHC-copper phosphides found to be most selective catalysts yet reported for hydrophosphination...

Abstract Phosphites are industrially important ligands for the Rh‐catalysed hydroformylation of olefins because they produce more active catalysts than phosphines, which is mainly due to their strong π‐acceptor properties facilitating CO dissociation from metal centre. Herein, effect three prominent phosphite (triphenylphosphite, Alkanox and BiPhePhos) on catalyst speciation during turnover investigated using multi‐nuclear operando FlowNMR spectroscopy. The quantitative distribution maps...

The in situ combination of [Ru(PPh3)3(CO)H2] with xantphos is catalytically active for the alkylation alcohols ketonitrile (t)BuC(O)CH2CN a model oxidation-Knoevenagel-reduction process. precursor complex [Ru(xantphos)(PPh3)(CO)H2] was isolated and reacted stoichiometric amounts PhCH2OH PhCHO. Under these conditions, alcohol decarbonylated to afford [Ru(xantphos)(CO)2H2] finally [Ru(xantphos)(CO)3], both which prove be less catalysis than starting complex. reactivity system contrasts that...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSimple molecular orbital explanation for the barrier to internal rotation in ethane and other moleculesJohn P. LoweCite this: J. Am. Chem. Soc. 1970, 92, 12, 3799–3800Publication Date (Print):June 1, 1970Publication History Published online1 May 2002Published inissue 1 June 1970https://pubs.acs.org/doi/10.1021/ja00715a049https://doi.org/10.1021/ja00715a049research-articleACS PublicationsRequest reuse permissionsArticle...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMolecular orbital theory of SN2 reactionsJohn P. LoweCite this: J. Am. Chem. Soc. 1971, 93, 2, 301–305Publication Date (Print):January 1, 1971Publication History Published online1 May 2002Published inissue 1 January 1971https://pubs.acs.org/doi/10.1021/ja00731a002https://doi.org/10.1021/ja00731a002research-articleACS PublicationsRequest reuse permissionsArticle Views536Altmetric-Citations40LEARN ABOUT THESE METRICSArticle Views are the...

Abstract Hydrogen oxidation and oxygen reduction are two crucial energy conversion reactions, which shown to be both strongly affected by the presence of intrinsically microporous polymer coatings on electrodes. Polymers intrinsic microporosity (PIMs) known possess extremely high internal surface area ability bind gases under dry conditions. It is here that both, hydrogen‐ gas binding into PIMs, also occurs wet or “triphasic” conditions in aqueous electrolyte environments (when immersed 0.01...