Investigation of ethynylpyridines using the electron propagator theory

The optimized geometry, dipole moment, and HOMO–LUMO gap for three monoethynylpyridines and six diethynylpyridines have been computed using DFT/B3LYP/6‐311++g(3df,3p) level of theory, and the first 11 vertical ionization energies and electron affinity of these compounds have been calculated using various electron propagator decouplings. The outer valence Green's function approximant of the electron propagator theory offers closest agreement with experimental photoelectron spectrum, and the results for structural suitability, dipole moment, HOMO–LUMO gap, ionization energies, and electron affinity indicate that 2‐ethynylpyridine among monoethynylpyridines and 2,6‐diethynylpyridine among diethynylpyridines may be useful precursors for the preparation of conducting polymers. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 112:426–439, 2012