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Strong Bases and beyond: The Prominent Contribution of Neutral Push–Pull Organic Molecules towards Superbases in the Gas Phase.

Authors :
Raczyńska, Ewa Daniela
Gal, Jean-François
Maria, Pierre-Charles
Source :
International Journal of Molecular Sciences. Jun2024, Vol. 25 Issue 11, p5591. 36p.
Publication Year :
2024

Abstract

In this review, the principles of gas-phase proton basicity measurements and theoretical calculations are recalled as a reminder of how the basicity PA/GB scale, based on Brønsted–Lowry theory, was constructed in the gas-phase (PA—proton affinity and/or GB—gas-phase basicity in the enthalpy and Gibbs energy scale, respectively). The origins of exceptionally strong gas-phase basicity of some organic nitrogen bases containing N-sp3 (amines), N-sp2 (imines, amidines, guanidines, polyguanides, phosphazenes), and N-sp (nitriles) are rationalized. In particular, the role of push–pull nitrogen bases in the development of the gas-phase basicity in the superbasicity region is emphasized. Some reasons for the difficulties in measurements for poly-functional nitrogen bases are highlighted. Various structural phenomena being in relation with gas-phase acid–base equilibria that should be considered in quantum-chemical calculations of PA/GB parameters are discussed. The preparation methods for strong organic push–pull bases containing a N-sp2 site of protonation are briefly reviewed. Finally, recent trends in research on neutral organic superbases, leaning toward catalytic and other remarkable applications, are underlined. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
16616596
Volume :
25
Issue :
11
Database :
Academic Search Index
Journal :
International Journal of Molecular Sciences
Publication Type :
Academic Journal
Accession number :
177850316
Full Text :
https://doi.org/10.3390/ijms25115591