The ion selectivity of the Goedken-Peng cryptand: prediction of ion selectivity by quantum chemical calculations XVII

Abstract

The cryptand developed by Virgil L. Goedken and Shie-Ming Peng, along with its interactions with alkaline and alkaline earth metal ions, was investigated using computational chemistry (B3LYP/LANL2DZp) to gain insight into the influence of the flexibility of the chelating N-C-C-N group on overall selectivity towards metal ions. According to DFT calculations, the most suitable cation for the cryptand is Li⁺, as Na⁺ is too large and would prefer a longer bond between Na⁺ and the N-donor. Additionally, the Be²⁺-N bond in the Goedken-Peng cryptand is excessively long compared to the Mg²⁺-N-cryptate bond, which is too short. The most effective method for hosting the guest cations is for the cryptand to twist itself, and the flexibility of the chelating N-C-C-N group serves as the most effective structural motive for the Goedken-Peng cryptand to interact with the guest cation.

Keywords:

• Goedken-Peng cryptand
• selective ion complexation
• DFT-study

Acknowledgements

We would like to thank Prof. Petra Imhof and Prof. Tim Clark for hosting this work at the CCC. T. Soldatović gratefully acknowledges financial support from State University of Novi Pazar, Republic of Serbia and Ministry of Science, Technological Development and Innovation of the Republic of Serbia (Agreement No-. 451-03-65/2024-03/200252). We are thankful to I. Shook for helpful discussions.

Author contributions

The manuscript was written with contributions from all authors.

Disclosure statement

No potential conflict of interest was reported by the authors.