Limitations of VBT

Key Shortfalls: $$\begin{aligned} \text{Color \& Spectra:} &\quad \text{Fails to account for the deep colors and electronic absorption spectra of complexes.} \\ \text{Thermodynamic Stability:} &\quad \text{Does not provide a quantitative measure of complex stability or bond strengths.} \\ \text{Magnetic Anomaly:} &\quad \text{Cannot explain why structural or magnetic properties change abruptly with temperature.} \end{aligned}$$

Concept: Outlines the core theoretical gaps of VBT that are frequently targeted in conceptual Assertion-Reason style evaluation matrices.

Notation:

• $$\text{Color \& Spectra}$$ = Addressed later by Crystal Field Theory via $$d\text{-}d$$ transitions;
• $$\text{Stability}$$ = Addressed by thermodynamic formation constants.