Experimental determination of partial charges with electron diffraction

Area of Science:

• Crystallography
• Quantum Chemistry
• Materials Science

Background:

• Atomic partial charges are crucial for understanding molecular behavior but lack a precise quantum-mechanical definition.
• Accurate determination of atomic partial charges has significant implications in chemical synthesis, materials science, and theoretical chemistry.
• Existing methods for quantifying atomic partial charges are limited, with no general experimental approach available until now.

Purpose of the Study:

• To introduce a novel experimental method for quantifying atomic partial charges in crystalline compounds.
• To provide a general and versatile approach applicable to any crystalline material.
• To enhance the understanding of molecular structure, interactions, and reactivity through precise charge determination.

Main Methods:

• The study introduces a new experimental method based on crystal structure determination via electron diffraction.
• This method, termed ionic scattering factors modelling, is integrated into standard electron crystallography workflows.
• No specialized software or advanced expertise is required, making the method broadly accessible.

Main Results:

• The method successfully assigns partial charges to individual atoms in various crystalline compounds.
• Demonstrated versatility across diverse examples, including the antibiotic ciprofloxacin, amino acids (histidine, tyrosine), and the zeolite ZSM-5.
• The ionic scattering factors modelling provides a more comprehensive and precise understanding of molecular structures.

Conclusions:

• The developed experimental method offers a general and accessible approach to determine atomic partial charges.
• Ionic scattering factors modelling significantly advances the precise understanding of molecular structures and chemical properties.
• This breakthrough opens new avenues for applications in chemical synthesis, materials science, and computational chemistry.