Rational Design of Cation Hosts – Prediction of Cation Selectivity by Quantum Chemical Calculations

Abstract

Summary Structures of [M ⊂ 2.2.2]n+ obtained with MNDO, AM1, PM3, PM3/SPASS, and PM5, are evaluated against X-ray and DFT (B3LYP/LANL2DZp) geometries. DFT and X-ray structures agree well, followed by PM3/SPASS. The ion selectivity calculated with DFT and PM3/SPASS for a simple model reaction, agrees satisfactorily with the available complex-formation constants (log K S). The applied theoretical treatment has a good predictive potential.