Reevaluating Valence-Shell Electron Pair Repulsion and Hybrid Atomic Orbitals in Chemical Education

Area of Science:

• Chemistry
• Quantum Chemistry
• Chemical Education

Background:

• The valence-shell electron pair repulsion (VSEPR) and hybrid orbital (HO) theories are widely used to predict molecular geometry.
• However, their fundamental validity and explanatory power have been subjects of ongoing debate within the scientific community.

Purpose of the Study:

• To critically evaluate the explanatory capabilities of VSEPR and HO theories regarding molecular shape.
• To propose molecular orbital (MO) theory as a more robust framework for understanding molecular geometry.

Main Methods:

• Analysis of simple molecular examples to challenge the primacy of VSEPR and HO theories.
• Introduction of the linear combination of atomic orbitals (LCAO) concept within MO theory.
• Development of visual representations to illustrate MO theory's application to molecular geometry.

Main Results:

• Demonstration that VSEPR and HO theories are conceptual constructs rather than primary determinants of molecular structure.
• Identification of MO theory, particularly through LCAO, as a more insightful approach.
• Visualizations effectively explain molecular geometry using MO theory.

Conclusions:

• VSEPR and HO theories require deconstruction and re-evaluation in chemistry education.
• Molecular orbital theory provides a more accurate and realistic model for understanding molecular geometry.
• MO theory offers a superior conceptual framework for chemical bonding and structure.