3.1.4: Lewis Fails to Predict Unusual Cases-Boron/Beryllium

• Lewis theory fails to predict structure in the cases of beryllium and boron.
• Boron trihalides have properties that are largely predicted by Lewis structures and VSEPR theory.
• The resonance hybrid of BF3 predicts partial double bond character between boron and fluorine, thus a bond length shorter than a single bond.
• Boron trihalides are electron deficient at the boron center and react readily with Lewis bases.
• Boron trihydride is not stable, but when dissolved in the presence of a Lewis base, can form a stable acid-base adduct.