Molecular Dynamics Simulation and Density Functional Theory Investigation for Thiacalix[4]biscrown and its Complexes with Alkali-Metal Cations

Abstract

The structural and energetic preferences of thiacalix [4]biscrown-5 with and without alkali metal ions (Na + , K + , Rb + , and Cs + ) have been theoretically investigated for the first time using molecular dynamic (MD) simulations and density functional theory (MPWB1K/6-31G(d)//B3LYP/6-31G(d)) methods. The formation of the metal ion complex by the host is mainly driven by the electrostatic attraction between crown-5 oxygens and a cation together with the minor contribution of the cation-π interaction between two facing phenyl rings around the cation. The computed binding energies and the atomic charge distribution analysis for the metal binding complexes indicate the selectivity toward a potassium ion. The theoretical results herein explain the experimentally observed extractability order by this host towards various alkali metal ions. The physical nature and the driving forces for cation recognition by this host are discussed in detail.

Thiacalix[4]‐bis‐crown with Hard Cavities and Soft Bridges Exhibiting Endocyclic Potassium(I) Complexes and Exocyclic Silver(I) Coordination Polymers

“…Thiacalixarenes have attracted considerable interest as a partner of “classical” calixarenes due to their isostructural topology and the additional coordinating sites in form of sulfur bridges . One of the most fascinating modification of a (thia)calixarene scaffold involves linking of two opposite aromatic units with crown moieties to give (thia)calixcrowns . Calix[4]‐bis‐crown family and their thiacalix analogues exhibit interesting common features including (1) two crown cavities able to undergo dinucleation and (2) HSAB (hard and soft acids and bases) based complexation selectivity.…”

“…Calix[4]‐bis‐crown family and their thiacalix analogues exhibit interesting common features including (1) two crown cavities able to undergo dinucleation and (2) HSAB (hard and soft acids and bases) based complexation selectivity. In addition, some metal ions are entrapped and stabilized not only by cation–donor binding in the crown cavities but also by cation–π interaction , . As far as we know, six examples of group 1A metal ion complexes of (thia)calix[4]‐bis‐crowns incorporating crown‐5 and/or crown‐6 moieties have been isolated and structurally characterized …”

mPW1PW91 Calculated Structures and IR Spectra of Thiacalix[4]biscrown-5 Complexed with Alkali Metal Ions

“…16 In this study, the structures and energies of thiacalix [4]biscrown-5 (1) and p-tert-butylthiacalix [4]biscrown-5 (2) and their alkali-metal-ion complexes were investigated using the mPW1PW91/6-31G(d,p) (hybrid HF-DF) calculations. The primary objective of this research was to determine the selectivity of the mono-and di-topic complexations of hosts 1 and 2 with sodium and potassium cations.…”