Proton-Transfer and H2-Elimination Reactions of Trimethylamine Alane: Role of Dihydrogen Bonding and Lewis Acid−Base Interactions

2009 ◽  
Vol 48 (8) ◽  
pp. 3667-3678 ◽  
Author(s):  
Oleg A. Filippov ◽  
Victoria N. Tsupreva ◽  
Lyudmila M. Golubinskaya ◽  
Antonina I. Krylova ◽  
Vladimir I. Bregadze ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Lewis Acid ◽  
Acid Base ◽  
Dihydrogen Bonding ◽  
Elimination Reactions ◽  
Trimethylamine Alane ◽  
H2 Elimination

Proton-Transfer and H2-Elimination Reactions of Main-Group Hydrides EH4-(E = B, Al, Ga) with Alcohols

2006 ◽  
Vol 45 (7) ◽  
pp. 3086-3096 ◽  
Author(s):  
Oleg A. Filippov ◽  
Andrey M. Filin ◽  
Viktoria N. Tsupreva ◽  
Natalia V. Belkova ◽  
Agustí Lledós ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Main Group ◽  
Elimination Reactions ◽  
H2 Elimination

scholarly journals Proton transfer vs. oligophosphine formation by P–C/P–H σ-bond metathesis: decoding the competing Brønsted and Lewis type reactivities of imidazolio-phosphines

2020 ◽  
Vol 49 (47) ◽  
pp. 17401-17413
Author(s):  
Mario Cicač-Hudi ◽  
Christoph M. Feil ◽  
Nicholas Birchall ◽  
Martin Nieger ◽  
Dietrich Gudat
Keyword(s):  
Proton Transfer ◽  
Lewis Acid ◽  
Acid Base ◽  
Reaction Cascades

Cationic imidazolio-phosphines show two-sided reactivity towards bases, undergoing either Brønsted-type proton transfer to imidazolio-phosphides or autocatalytic Lewis acid/base reaction cascades to yield P-free imidazolium ions and oligophosphines.

Analysis of the role of a writing-to-learn assignment in student understanding of organic acid–base concepts

2019 ◽  
Vol 20 (2) ◽  
pp. 383-398 ◽  
Author(s):  
Jennifer A. Schmidt-McCormack ◽  
Jessyca A. Judge ◽  
Kellie Spahr ◽  
Ellen Yang ◽  
Raymond Pugh ◽  
...  
Keyword(s):  
Treatment Group ◽  
Peer Review ◽  
Lewis Acid ◽  
Comparison Group ◽  
Writing To Learn ◽  
Chemistry Curriculum ◽  
Acid Base ◽  
External Assessment ◽  
Writing Assignment

Acid–base chemistry is a foundational topic that is taught in courses across the chemistry curriculum. Students often have difficulty distinguishing between the different theories of acid–base chemistry—Brønsted–Lowry and Lewis acid–base chemistry—and applying these two definitions correctly in unfamiliar scenarios. To help students learn these definitions and be able to apply them, an acid–base Writing-to-Learn assignment was developed and evaluated. The Writing-to-Learn assignment involved a three-step process where students constructed an initial draft in response to a writing prompt, participated in peer review, and made revisions based on peer review feedback, before submitting a final draft. This process is informed by sociocultural theory applied to writing, which states that student learning of concepts increases through engagement with their peers’ work and receiving peer feedback on their own writing. To test the efficacy of the acid–base writing assignment, an external assessment, comprised of conceptual questions related to acid–base chemistry and students’ confidence when responding to them, was administered in two groups; a treatment group who completed the Writing-to-Learn assignment, and a comparison group who completed a separate assignment. Additionally, students who completed the Writing-to-Learn assignment were interviewed about their experiences. Regression analysis revealed that students in the treatment group had a greater increase in their conceptual understanding and confidence as compared to the students in the comparison group. The results demonstrate the students could successfully write about the Brønsted–Lowry and Lewis acid–base models separately, but were less successful with connecting these two concepts together in their writing. These results demonstrate the efficacy of Writing-to-Learn as an approach for promoting conceptual learning of acid–base chemistry.

Halogen Adsorption on CeO2: The Role of Lewis Acid–Base Pairing

2012 ◽  
Vol 116 (11) ◽  
pp. 6664-6671 ◽  
Author(s):  
Zhenpeng Hu ◽  
Horia Metiu
Keyword(s):  
Lewis Acid ◽  
Base Pairing ◽  
Acid Base

A QM/MM study of Kemptide phosphorylation catalyzed by protein kinase A. The role of Asp166 as a general acid/base catalyst

2015 ◽  
Vol 17 (5) ◽  
pp. 3497-3511 ◽  
Author(s):  
Ayax Pérez-Gallegos ◽  
Mireia Garcia-Viloca ◽  
Àngels González-Lafont ◽  
José M. Lluch
Keyword(s):  
Protein Kinase ◽  
Proton Transfer ◽  
Protein Kinase A ◽  
Base Catalyst ◽  
Acid Base ◽  
General Acid ◽  
Kinase A

QM/MM calculations show that Asp166 is a general acid/base catalyst along the phosphoryl and proton transfer steps of Kemptide phosphorylation by protein kinase A.

scholarly journals CATALYTIC INFLUENCE OF NITROGEN-CONTAINING BASE ON COMPLEXATION OF OCTA(m-TRIFLUOROMETHYLPHENYL)PORPHYRAZINE AND HEXA(m-TRIFLUOROMETHYLPHENYL)BENZOPORPHYRASINE

2020 ◽  
Vol 63 (6) ◽  
pp. 4-11
Author(s):  
Galina V. Osipova ◽  
Oleg A. Petrov
Keyword(s):  
Proton Transfer ◽  
Zinc Acetate ◽  
Kinetic Stability ◽  
Zinc Complexes ◽  
Complexation Reaction ◽  
Acid Base ◽  
Base Interaction ◽  
Base Complex ◽  
Ion Associate

The review presents data on the complexation of octa(m-trifluoromethylphenyl)porphy-razine and hexa(m-trifluoromethylphenyl)benzoporphyrazine with zinc acetate in a system nitrogen-containing base - benzene. It was shown that the investigated porphyrazines, having pronounced acidic properties at the incyclic NH bonds, interact with n-butylamine, tret-butylamine, morpholine and piperidine in benzene with the formation of proton-transfer complexes. In these complexes, the intocyclic protons of the NH-groups associated with the oxygen atom of the dimethyl sulfoxide molecule and the intocyclic nitrogen atoms are located above and below the plane of the macrocycle. In an inert, low-polar benzene, the degree of proton transfer from acid to base is limited by the stage of the H-complex (H-associate) formation or ionic complex (ion-ion) associate. It was found that proton transfer complexes of octa(m-trifluoromethylphenyl)porphyrazine and hexa(m-trifluoromethylphenyl)benzoporphyrazine exhibit low kinetic stability. The role of this acid - base interaction in the complexation reaction of octa(m-trifluoromethylphenyl)-porphyrazine and hexa(m-trifluoromethylphenyl)benzoporphyrazine with zinc acetate is shown. High kinetic stability of zinc complexes with the investigated porphyrazines in contrast to complexes with proton transfer was revealed. Based on the analysis of kinetic data, it was found that the introduction of Zn2+ into the coordination center of octa(m-trifluoromethylphenyl)porphyrazine and hexa(m-trifluoromethylphenyl)benzoporphyrazine is preceded by the stage of interaction of porphyrazine with a nitrogen-containing base. This leads to the formation of an intermediate reactive acid-base complex that differs in composition from complexes with proton transfer of porphyrazines. It was shown that piperidine and n-butylamine exert the maximum catalytic effect on the formation of zinc complexes with the investigated porphyrazines. A decrease in the pKa of the nitrogen-containing base, as well as an increase in the spatial shielding of the nitrogen atom in the amine by alkyl substituents, counteracts the formation of an intermediate acid-base complex and, as a result, reduces the complexation rate of octa(m-trifluoromethylphenyl)porphyrazine and hexa(m-trifluoromethylphenyl)benzoporphyrazine with zinc acetate in benzene.

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