Pnicogen and hydrogen bonds: complexes between PH3X(+) and PH2X systems.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Supramolecular Chemistry

Background:

• Analysis of charge-assisted complexes between phosphine derivatives.
• Understanding non-covalent interactions in chemical systems.

Purpose of the Study:

• To investigate the structural and energetic properties of PH3X(+)–PH2X complexes.
• To identify and characterize different types of bonding interactions, including pnicogen and hydrogen bonds.

Main Methods:

• Ab initio calculations using MP2/aug'-cc-pVTZ.
• Supportive analysis via Quantum Theory of Atoms in Molecules (QTAIM).
• Natural Bond Orbitals (NBO) method for charge transfer analysis.

Main Results:

• Three distinct configurations identified: P···P pnicogen bonds, P···X pnicogen bonds, and P-H···P hydrogen bonds.
• P···P configurations demonstrated the highest stability and strongest interactions.
• Correlations found between P···P bond distance, electron density at the bond critical point (ρPP), and charge transfer energy.

Conclusions:

• P···P pnicogen bonds are the dominant stabilizing interaction in these complexes.
• The study provides insights into the nature of charge-assisted interactions involving phosphine derivatives.
• Established relationships between structural and electronic parameters offer predictive capabilities for similar systems.