Results 1 to 10 of about 60,540 (292)

Substituent Effects in Ugi–Smiles Reactions

The Journal of Physical Chemistry A, 2013
In a recent communication, we described the mechanism of the well-known Ugi-type reactions with a model system (J. Org. Chem. 2012, 77, 1361-1366). Herein, focusing on the Ugi-Smiles coupling, we study the effects of each of the four reactants on the energy profile to further explain the experimental results.
Chéron, Nicolas, Ramozzi, Romain, El Kaim, Laurent, Grimaud, Laurence, Fleurat-Lessard, Paul   +4 more
openaire   +3 more sources

Dual Substituent Parameter Modeling of Theoretical, NMR and IR Spectral Data of 5-Substituted Indole-2,3-diones

Molecules, 2002
Correlations of AM1 and PM3 theoretical data, 13C-NMR substituent chemical shifts (13C-SCS) and IR carbonyl group wave numbers [ν(C3═O)] were studied using dual substituent parameter (DSP) models for 5-substituted indole-2,3-diones.
Zora Å usteková, Katri Laihia, Walter M.F. Fabian, Erkki Kolehmainen, Mária Å amalíková, Alexander Perjéssy, Hanan A. Radhy, Ghazwan F. Fadhil   +7 more
doaj   +1 more source

Aromatic Metal Corrosion Inhibitors

Corrosion and Materials Degradation
Molecular inhibitors added to the corrosive medium attacking metallic materials are a well-established way of combating corrosion. The inhibitive action proceeds via adsorption of the inhibitor on the surface to be protected.
Jessica Roscher, Dan Liu, Xuan Xie, Rudolf Holze   +3 more
doaj   +1 more source

Synthesis, Spectroscopy and Electrochemistry in Relation to DFT Computed Energies of Ferrocene- and Ruthenocene-Containing β-Diketonato Iridium(III) Heteroleptic Complexes. Structure of [(2-Pyridylphenyl)₂Ir(RcCOCHCOCH₃]

Molecules, 2019
A series of new ferrocene- and ruthenocene-containing iridium(III) heteroleptic complexes of the type [(ppy)2Ir(RCOCHCOR′)], with ppy = 2-pyridylphenyl, R = Fc = FeII(η5-C5H4)(η5-C5H5) and R′ = CH3 (1) or Fc (2), as well as R = Rc =
Blenerhassitt E. Buitendach, Jeanet Conradie, Frederick P. Malan, J. W. (Hans) Niemantsverdriet, Jannie C. Swarts   +4 more
doaj   +1 more source

Quantitative Analysis of Substituent Effects in Cu(II) and Co(II) Benzimidazole Complexes: Stability Constants Determined via Acetate-Mediated Synthesis and Benesi–Hildebrand Method Correlated with Hammett σ Parameters

Chemistry
This study presents a quantitative investigation of substituent effects on the stability of 1:2 complexes formed between para-substituted 2-phenylbenzimidazole ligands and Cu(II) or Co(II) ions.
Zoltán Köntös, Flóra Stedra, Viktória Ngo Hang   +2 more
doaj   +1 more source

Substituent effects on the photophysics of the kaede chromophore [PDF]

Physical Chemistry Chemical Physics
Ultrafast time resolved spectroscopy probes substituent dependent photophysics of the kaede fluorescent protein chromophore.
Anam Fatima, Giovanni Bressan, Eleanor K. Ashworth, Philip C. B. Page, James N. Bull, Stephen R. Meech   +5 more
openaire   +3 more sources

Competitive Heavy‐Atom Tunneling Reactions Controlled Through Electronic Effects

ChemistryEurope
Controlling QMT reactivity remains exceptionally challenging and largely unexplored, as it requires rationales distinctly different from those used for classical chemical reactivity.
José P. L. Roque, Cláudio M. Nunes, Fumito Saito, Bastian Bernhardt, Rui Fausto, Peter R. Schreiner   +5 more
doaj   +1 more source

Substituent effects on imidazole derivatives

, 2010
Üç bölümden oluşan bu tez 1,3-disübstitüye imidazolyum bromürlerin (1-5) sentezi ve katalitik özellikleriyle ilgilidir. Birinci bölüm imidazollere ait temel bilgiler, önemi ve kullanımları hakkında kısa bir derlemedir. İkinci bölümde deneysel veriler ayrıntılı bir biçimde açıklanmıştır. Üçüncü bölüm 1,3-disübstitüye imidazolyum tuzlarının sentezi, yapı
openaire   +2 more sources

Atomic Charges from Machine-Learned Charge Densities: Consistency and Substituent Effects

Chemistry
Atomic charges are widely used to analyze molecular electronic structure and substituent effects, yet their numerical values and interpretations are inherently dependent on the adopted density partitioning scheme.
Xuejian Qin, Taoyuze Lv
doaj   +1 more source

Lone‐Pair Shielded Radicals: Beyond the Captodative Substitution Pattern

ChemistryEurope
We have quantum chemically analyzed how substituents R affect the carboncarbon bond strength in 1,2‐disubstituted ethane, RH2CCH2R (R = H, CH3, NH2, OH, F), using density functional theory.
Steven E. Beutick, Maarten J. H. van Dorp, Trevor A. Hamlin, J. Martijn van der Schuur, Daniela Rodrigues Silva, F. Matthias Bickelhaupt   +5 more
doaj   +1 more source