Isomerization Processes in Ions of the Empirical Formula

Area of Science:

• Physical Chemistry
• Chemical Physics
• Ion Chemistry

Background:

• The C4H8+ ion exists in various isomeric forms with different energies.
• Understanding ion structures and isomerization is crucial for reaction mechanisms.

Purpose of the Study:

• To determine the structures of C4H8+ ions generated from different precursors.
• To investigate the isomerization pathways and energy requirements of C4H8+ ions.
• To study the influence of collision partners on ion stability and isomerization.

Main Methods:

• Generation of C4H8+ ions using photons (10-11.8 eV) and gamma radiation from various C4H8 isomers.
• Structure determination via charge transfer reactions with dimethylamine and nitric oxide.
• Analysis of C4H8+ isomerization and collisional deactivation at varying pressures.
• Investigation of energy transfer efficiency with different deactivator gases (He, H2, Ne, Kr, Xe, N2, CO2).

Main Results:

• C4H8+ ions isomerize to thermodynamically stable structures, predominantly the cyclobutane radical cation, at low pressures.
• Ion yield shifts indicate that collisionally deactivated precursors form the cyclobutane radical cation.
• Higher photon energy (11.6-11.8 eV) significantly enhances isomerization compared to lower energy (10 eV).
• Energy transfer efficiency to deactivators correlates with their polarizability.

Conclusions:

• The internal energy of the initially formed C4H8+ ion dictates its isomerization potential.
• Collisional deactivation plays a key role in stabilizing specific ion structures.
• The polarizability of deactivator molecules influences the efficiency of energy transfer from C4H8+ ions.