Halide-propene complexes: validated DSD-PBEP86-D3BJ calculations and photoelectron spectroscopy

Area of Science:

• Physical Chemistry
• Spectroscopy
• Computational Chemistry

Background:

• Halide-molecule complexes are crucial in atmospheric and extraterrestrial chemistry.
• Understanding their electronic properties informs reaction mechanisms.

Purpose of the Study:

• To determine electron binding energies of X⁻⋯C₃H₆ complexes (X = Cl, Br, I).
• To validate computational methods for studying such van der Waals complexes.
• To explore potential formation pathways of haloalkyl radicals.

Main Methods:

• Anion photoelectron spectroscopy (PES) was used to measure electron binding energies.
• The DSD-PBEP86-D3BJ functional was employed for theoretical calculations.
• Computational results were validated against experimental and CCSD(T)/CBS data.

Main Results:

• Electron binding energies were determined for chlorine, bromine, and iodine complexes.
• Two distinct coordination structures of the halide ion with propylene were identified.
• Calculated geometries and vertical detachment energies aligned well with experimental data.

Conclusions:

• The study provides key experimental and computational data for halide-propylene complexes.
• Identified structures and binding energies offer insights into atmospheric and extraterrestrial radical formation.
• These complexes may serve as entry points for haloalkyl radical synthesis.