Molecular structure of 5,10,15,20-tetrakis(4′-fluorophenyl)porphyrin by combined gas-phase electron diffraction/mass spectrometry experiment and DFT calculations

Molecular parameters of 5,10,15,20-tetrakis(4′-fluorophenyl)porphyrin were determined for the first time by gas-phase electron diffraction. Conformational preference was investigated based on the experimental data and was found to be in the good agreement with the preliminary model-based considerations. The experimental vibrational spectrum was measured and assigned. The structural features were compared with that of the previously studied Zn(II) and Pd(II) complexes with tetraphenylporphyrin. The results of the Knudsen effusion mass spectrometry experiment yielded the value of the sublimation enthalpy of Δ sub H °( 584 К ) = 233(4) kJ mol −1 . The introduction of substituents into the para -position of phenyl fragments does not significantly affect the electron density distribution and geometry of the coordination cavity. • First experimental study of H 2 P–4C 6 H 4 F molecular structure in gas phase was performed. • The sublimation enthalpy of H 2 P–4C 6 H 4 F were obtained. • Conformational analysis of H 2 P–4C 6 H 4 F using DFT calculations and GED was carried out. • Assignment of vibrational spectrum of H 2 P–4C 6 H 4 F was performed.