Theoretical study of geometry and nucleophilicity of the exocyclic methylene in five-membered ring cyclic ketene acetals, neutral and protonated, containing pnictogen and chalcogen heteroatoms
| Autor: | Svein Saebo, Debbie J. Beard, Adam E. Catoire |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
chemistry.chemical_classification
Double bond Heteroatom Ketene Condensed Matter Physics Ring (chemistry) Photochemistry Transition state Bond length chemistry.chemical_compound chemistry Computational chemistry Physics::Atomic and Molecular Clusters Physics::Chemical Physics Physical and Theoretical Chemistry Methylene Pnictogen |
| Zdroj: | Structural Chemistry. 25:371-376 |
| ISSN: | 1572-9001 1040-0400 |
| DOI: | 10.1007/s11224-013-0338-6 |
| Popis: | A series of neutral and protonated five-membered ring cyclic ketene acetals have been examined computationally for any trends in nucleophilicity in the exocyclic methylene and for their ground state geometries. A total of 58 different species were examined, 29 neutral molecules and the corresponding 29 protonated species. The heteroatoms that were used in the heterocyclic ring were a combination of nitrogen, phosphorus, and arsenic from the pnictogen family and oxygen, sulfur, and selenium from the chalcogen family. All geometries were initially optimized at using density functional theory and all stationary points were confirmed to be either minima or transition states through vibrational analysis. All the geometries were consequentially optimized using Moller–Plesset second order perturbation theory with a polarized triple zeta basis set. The main focus of the study was the nucleophilicity of the exocyclic methylene carbon atom and its dependence on heteroatom substitution. As probes for nucleophilicity, the proton affinities of the neutral species, the bond lengths of the exocyclic double bond, and atomic charges were used. The study also resulted in some interesting molecular geometries. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink