Cation recognition controlled by protonation or chemical reduction: a computational study

Author(s)

Orenha, Renato Pereira ; Borges, Alexandre ; de Oliveira Andrade, Ana Livia ; Ferreira, Sergio Eduardo ; Furtado, Saulo Samuel Pereira ; Glitz, Vinicius Acir ; Caramori, Giovanni Finoto ; Parreira, Renato Luis Tame

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 25, n. 22, p. 13-pg., 2023-05-17.

Abstract

To control biochemical processes, non-covalent interactions involving cations are activated by protons or electrons. In the present study, the bonding situation between: (i) carboxylic acid or (ii) ferrocene-functionalized crown ether derivatives and cations (Li+, Na+ or K+) has been elucidated and, mainly, tuned by the substitution of hydrogen atoms by electron donor (-NH2) or acceptor (-NO2) groups. The deprotonation of the carboxyl groups improves the interaction with the cations through more favorable electrostatic OMIDLINE HORIZONTAL ELLIPSIScation interactions. Reducing the ferrocene structures favors cationic recognition supported by a less unfavorable ironMIDLINE HORIZONTAL ELLIPSIScation binding. The receptors preferably interact with smaller cations because of more attractive electrostatic and orbital (sigma or pi) OMIDLINE HORIZONTAL ELLIPSIScation interactions. The presence of electron donor or acceptor groups in the carboxylic acid-functionalized crown ethers promotes less attractive interactions with the cations, mainly due to the less favorable electrostatic OMIDLINE HORIZONTAL ELLIPSISNa+ interactions. The -H -> -NH2 substitution in the ferrocene framework favors the cationic recognition. It is based on the strengthening of the electrostatic and sigma OMIDLINE HORIZONTAL ELLIPSISNa+ and H2NMIDLINE HORIZONTAL ELLIPSISNa+ bonds. The (i) absence of repulsive electrostatic ironMIDLINE HORIZONTAL ELLIPSIScation interactions, or (ii) the presence of oxygen atoms with large electron density, ensures carboxylic acid-functionalized crown ethers have more favorable interactions with cations than ferrocene compounds. Therefore, this work has demonstrated how cation recognition can be improved by structural changes in carboxylic acid- or ferrocene-functionalized crown ethers and has shown that the carboxylic acid molecules appear to be better candidates for cation recognition than ferrocene derivatives. (AU)

• FAPESP's process: 11/07623-8 - The use of quantum-mechanical methods to study the bonds and chemical interactions in self-organizing systems with applications in catalysis, medicinal chemistry, electrochromism, energy storage and conversion
• Grantee: Renato Luis Tame Parreira
• Support Opportunities: Research Grants - Young Investigators Grants