Electron-driven molecular processes for cyanopolyacetylenes HC₂N (n = 3, 4, and 5)

Area of Science:

• * Astrochemistry and Quantum Chemistry
• * Molecular Physics

Background:

• * Linear carbon series cyanopolyacetylenes (HC₂N) are detected in Titan's atmosphere and interstellar environments like TMC-1 and IRC +10°216.
• * Experimental studies on these molecules are limited due to handling difficulties and associated health risks.

Purpose of the Study:

• * To comprehensively investigate electron interactions with HC₇N, HC₉N, and HC₁₁N.
• * To quantify various electron-driven molecular processes, including elastic and inelastic scattering, ionization, and electronic excitation.
• * To provide the first theoretical cross-section data for these specific cyanopolyacetylene compounds.

Main Methods:

• * Quantum spherical complex optical potential (SCOP) method for elastic (Q_el) and inelastic (Q_inel) cross-sections.
• * Complex scattering potential-ionization contribution (CSP-ic) method for ionization (Q_ion) and electronic excitation (ΣQ_exc) cross-sections.
• * Two-parameter semi-empirical method (2p-SEM) for validation of Q_el and total cross-sections (Q_T).

Main Results:

• * Comprehensive cross-section data (Q_el, Q_inel, Q_ion, ΣQ_exc, Q_T) for HC₇N, HC₉N, and HC₁₁N from ionization threshold to 5 keV.
• * Maiden theoretical reports on Q_el, Q_inel, ΣQ_exc, and Q_T for these molecules.
• * Prediction of polarizability for HC₁₁N based on established correlations.

Conclusions:

• * The study provides essential theoretical data for understanding electron-molecule interactions involving cyanopolyacetylenes.
• * The results serve as a crucial reference for astrochemistry and atmospheric modeling.
• * Novel polarizability prediction for HC₁₁N expands the knowledge base for this class of molecules.