Using density functional theory we investigate the ground-state geometries and electronic structures of calixpyrrole (C4P) and its fluorine analogue (F-C4P). The HOMO-LUMO energy gap of C4P is 5.9 eV and remains nearly the same upon H-by-F replacement (5.7 eV). Fluorine substitution increases both the vertical and adiabatic ionization potentials of C4P by ∼0.8 eV while the electron affinity of either macrocycle is negative thus indicating that the corresponding radical anion in the gas-phase is thermodynamically unstable. It is shown that the topology of the LUMOs of both C4P and F-C4P have important implications for the spherical recognition of halide anions. The simulated IR, NMR, and electronic spectra display important fingerprints for the characterization of these macrocycles.
- Electronic structure
- Theoretical spectra
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry