Charge-density distribution in sodium bis(4-nitrophenyl)phosphate

Area of Science:

• Solid-state chemistry
• Crystallography
• Computational chemistry

Background:

• Understanding electron distribution in organophosphates is crucial for predicting chemical properties and reactivity.
• Sodium bis(4-nitrophenyl)phosphate is a relevant compound for studying bonding characteristics due to its functional groups.

Purpose of the Study:

• To analyze the electron-density distribution in sodium bis(4-nitrophenyl)phosphate.
• To investigate the nature of P-O bonds and atomic charges using experimental and theoretical methods.
• To explore the influence of sodium cations on the electron distribution within the molecule.

Main Methods:

• Multipole refinement of X-ray diffraction data.
• Theoretical density-functional theory (DFT) calculations.
• Topological analysis of electron density at bond critical points.

Main Results:

• Identified unusually long ester P-O bonds with reduced topological parameters (density, Laplacian).
• Observed discrepancies between experimental and theoretical atomic charges in the nitro groups.
• Detected weak polarization effects from sodium cations, particularly on the nitro groups.

Conclusions:

• The study elucidates unique bonding characteristics in sodium bis(4-nitrophenyl)phosphate.
• Discrepancies in charge distribution highlight the need for careful interpretation of experimental and theoretical data.
• Sodium cation interactions play a role in modulating the electronic structure of the phosphate and nitro groups.