Exploring Intrinsic Bond Properties with the Fukui Matrix from Conceptual Density Matrix Functional Theory

Area of Science:

• Quantum Chemistry
• Theoretical Chemistry
• Computational Chemistry

Background:

• Conceptual Density Functional Theory (CDFT) traditionally uses external potentials.
• Investigating intrinsic bond properties like reactivity requires new theoretical frameworks.

Purpose of the Study:

• Extend CDFT to Conceptual Density Matrix Functional Theory (CDMFT).
• Develop a method to quantify intrinsic bond reactivity.
• Introduce the Fukui matrix as a descriptor for bond order changes.

Main Methods:

• Replaced the external potential v(r) with the one-electron integral h_rs in the energy functional.
• Derived the Fukui matrix (derivative of density matrix P with respect to electron number N).
• Utilized Mayer bond order and atoms-in-molecules partitioning for validation.

Main Results:

• The Fukui matrix quantifies bond strength changes upon electron addition/removal via the bond order derivative.
• The bond order derivative shows good agreement with finite difference calculations.
• The bond order derivative successfully predicts regioselectivity in electrophilic addition and bond cleavage in mass spectrometry.

Conclusions:

• CDMFT offers a novel approach to studying intrinsic bond properties.
• The Fukui matrix and bond order derivative are effective descriptors of bond reactivity.
• This method accurately predicts chemical reaction mechanisms and fragmentation patterns.