Dirhodium-catalyzed C-H amination is hypothesized to proceed via Rh2-nitrene intermediates in either the Rh2(II,II) or Rh2(II,III) redox state. Herein, we report joint theoretical and experimental studies of ground electronic state (GES), potentials, [Rh2(II,III)(O2CCH3)4(L)n](+) (1_L) (L = none, Cl(-), H2O), [Rh2(esp)2](+) (2), Rh2(espn)2Cl (3) (esp α,α,α',α'-tetramethyl-1,3-benzenedipropanoate espn α,α,α',α'-tetramethyl-1,3-benzenedipropanamidate). CASSCF calculations on 1_L yield a wave...

The catalytic activity of the bis(allyl)−ruthenium(IV) dimer [{Ru(η3:η3-C10H16)(μ-Cl)Cl}2] (C10H16 = 2,7-dimethylocta-2,6-diene-1,8-diyl) (1), and that its mononuclear derivatives [Ru(η3:η3-C10H16)Cl2(L)] (L CO, PR3, CNR, NCR) (2) [Ru(η3:η3-C10H16)Cl(NCMe)2][SbF6] (3), in redox isomerization allylic alcohols into carbonyl compounds, both tetrahydrofuran water, is reported. In particular, a variety have been quantitatively isomerized using (1) as catalyst, reactions proceeding all cases...

Simple 1,3-dienes undergo highly stereoselective hetero-Diels–Alder additions with SO2 at low temperature giving sultines. These reactions that are faster than the more exothermic cheletropic of SO2-producing sulfolenes. This has led to invention a new C–C bond-forming reaction combining electron-rich dienes and alkenes SO2. The cascade been exploited develop combinatorial, one-pot, four-component syntheses polyfunctional sulfones, sulfonamides, sulfonic esters. It also allows us generate,...

In order to achieve reproducibility during iridium-photoredox and nickel dual-catalyzed sp(3)-sp(2) carbon-carbon bond-forming reactions, we investigated the role that molecular oxygen (O2), solvent light-source (CF lamp or blue LED) play in a variety of Ir-photoredox mediated transformations. The presence O2 was discovered be important for catalyst activation when air-stable Ni(II) precatalysts were used DMF under CF irradiation; however, not required catalysis conducted with Ni(COD)2 same...

Calculations with Gaussian orbitals and periodic boundary conditions using several density functionals are carried out to study the proton-doping of polyaniline. We explore previously proposed mechanisms explain spectacular increase electrical conductivity polyaniline upon protonation. The structural spectroscopic theoretical predictions for both polaron bipolaron lattices agree quite well experimental data, we find that structure is lower in energy.

The intermolecular enantioselective C-H functionalization with acceptor-only metallocarbenes is reported using a new family of Ir(iii)-bis(imidazolinyl)phenyl catalysts, developed based on the interplay experimental and computational insights. reaction tolerant variety diazoacetate precursors found to be heavily influenced by steric electronic properties substrate. Phthalan dihydrofuran derivatives are functionalized in good yields excellent enantioselectivities.

Recently, a small number of diverse iridium complexes have been shown to catalyze unusual atom transfer C–H functionalization reactions. To further our understanding and enhance the utility for functionalization, we report design synthesis family iridium(III)-bis(oxazolinyl)phenyl complexes. The ability tune ligand environment around metal in these systems is exploited with asymmetric insertion donor/acceptor carbenoids into activated bonds. Low catalyst loadings (0.5 mol%) routinely lead...

A general mechanism to rationalize Ru(IV) -catalyzed isomerization of the C=C bond in O-allylic substrates is proposed. Calculations supporting proposed were performed at MPWB1K/6-311+G(d,p)+SDD level theory. All experimental observations different solvents (water and THF) under pH conditions (neutral basic) can be interpreted terms new mechanism. Theoretical analysis transformation from precatalyst catalyst led structural identification active species media. The experimentally observed...

The potential energy surfaces of the desulfinylation prop-2-enesulfinic acid (13) in CH(2)Cl(2) solution at -15 degrees C have been explored by quantum calculations and analyzed with kinetic data obtained for reaction absence or presence additives. Monomeric 13 adopts a preferred conformation gauche S=O/sigma(C(1)-C(2) bond pairs O-H pointing toward C(3). It equilibrates more stable dimer (13)(2) (at C) formed two O-H...O=S hydrogen bonds which S=O/sigmaC(1)-C(2) are also, but SOH moieties...

Polysulfone- and diphenyldisulfone-catalyzed alkene isomerizations are much faster for 2-alkyl-1-alkenes than linear, terminal alkenes. The mechanism of these reactions has been investigated experimentally the isomerization methylidenecyclopentane into 1-methylcyclopentene, theoretically [CCSD(T)/6-311++G(d,p)//B3LYP/6-311++G(d,p) calculations] propene 2-methylpropene with a methanesulfonyl radical, MeSO2•. On heating, polysulfones (PhSO2)2 equilibrate sulfonyl radicals, RSO2•. latter...

A new mechanism for the formation of doped polyaniline is presented. Besides providing suitable structural and spectroscopic parameters, allows rationalization experimentally observed equilibrium between polaron bipolaron defects in emeraldine salt. The magnetic behavior "metallic island" model conduction are also theoretically supported by proposal.

The first ene reactions of SO2 and unfunctionalized alkenes are reported. Calculations suggest that the endergonic with can be used to generate β,γ-unsaturated sulfinyl sulfonyl compounds. Indeed, in presence one equivalent BCl3, unstable sulfinic acid form stable acid⋅BCl3 complexes reacted situ NCS corresponding chlorides, or a base sulfinates. latter electrophiles sulfones, silyl chloride ethers act as oxygen nucleophiles produce esters. Thus one-pot, three-component synthesis...

The DFT approach is used to analyse the mechanism and controlling factors of (PDI)FeII(N2)2 (PDI)FeIICl(OEt2) complexes (i.e. a combination earth-abundant metal (Fe) non-innocent bis(imino)pyridine (PDI) ligand) catalyzed benzylic C–H bond functionalization by unsubstituted donor–acceptor diazocarbenes. Results suggest that use (PDI)FeCl(OEt2) complex carbenes absolutely necessary for alkylation. Furthermore, PDI ligand acts as one-electron oxidant upon formation reactive (PDI)Fe(Cl)CR1R2 carbenoid.

The Density Functional Theory (DFT) method is used to elucidate the nature of active species and mechanism aerobic CuI-catalyzed cross-coupling S-acyl thiosalicylamide thiol esters boronic acids reported previously (J. Am. Chem. Soc.2007, 129, 15734-15735; Angew. Chem., Int. Ed.2009,48, 1417-1421). energetically lowest isomer proposed [LC(O)R1]Cu-(O2)-Cu[LC(O)R1]2+, 2a, (where L = thiolatosalicylamide) found be I1(OO,OO) with a μ-η2:η2-peroxo Cu2O2-core, while its isomers I2(OO,OO) bis-(μ-O)...

Variational transition-state theory rate constants with multidimensional tunneling contributions using the small curvature method have been calculated for CF3CH2CH3 (HFC-263fb) + OH reaction over a temperature range from 200 to 373 K. The mPW1B95-41.0 hybrid functional, parametrized by Albu and Swaminathan generate theoretical nearly identical experimental values CH3F reaction, has used in conjunction 6-31+G** basis set explore potential energy surface of title reaction. good agreement found...

The gas-phase reactivity of methyl fluoride with selected first-row transition metal monocations (Sc(+), Ti(+), V(+), and Zn(+)) has been theoretically investigated. Our thermochemical kinetics study shows that early transition-metal cations exhibit a much more active chemistry than the latest monocation Zn(+). strong C-F bond in fluorine can be activated by scandium, titanium, vanadium yielding cation, MF(+). However, rate efficiencies vary dramatically along period 0.73 (Sc), 0.91 (Ti),...

The gas-phase reaction between calcium monocation and fluoromethane: Ca(+)+CH(3)F-->CaF(+)+CH(3) was theoretically analyzed. potential energy hypersurface explored by using density functional theory methodology with different functionals Pople's, Dunning's, Ahlrichs', Stuttgart-Dresden basis sets. Kinetics calculations (energy total angular momentum resolved microcanonical variational/conventional theory) were accomplished. predicted range for the global kinetic rate constant values at 295 K...

Variational transition-state theory rate constants with multidimensional tunneling contributions using the small curvature method have been calculated for CF(3)CHFCH(2)F (HFC-245eb) + OH reaction over a temperature range from 200 to 800 K. The mPW1B95-41.0 hybrid functional, parametrized by Albu and Swaminathan generate theoretical nearly identical experimental values CH(3)F reaction, has used in conjunction 6-31+G(d,p) basis set explore potential energy surface of title reaction. functional...

<div> <p>A series of complexes between neutral Valine and methane that feature potential homopolar C-H∙∙∙H-C contacts were located on the MP2/aug-cc-pVTZ energy hypersurface. In order to better estimate strength this contacts, interaction energies improve by single-point calculations at different levels theory (MP2, CCSD(T), SAPT2, SAPT2+3) together with Dunning’s basis sets (aug-cc-pVXZ; X=T,Q,5). Topological analysis electron density within QTAIM framework, NCI plots...