Group 13 - Chemistry of the Elements

Practice flashcards covering Group 13 elements, including their physical trends, halides, catalysis, and industrial applications based on the CHEM2077 lecture notes.

Group 13 valence electron configuration

The electron configuration of Group 13 elements, specifically $ns^2 np^1$.

Inert Pair Effect

The trend where the +1 oxidation state becomes increasingly stable relative to the +3 state when descending the group, due to the energy required to involve the $6s^2$ electrons in bonding for heavier elements like Thallium ($Tl$).

Alternation Effect (d-block Contraction)

Anomalies in trends at Gallium ($Ga$) caused by poor shielding from the $3d$ electrons, leading to a higher effective nuclear charge ($Z_{eff}$), a smaller atomic radius, and a higher first ionization energy than Aluminium ($Al$).

Boron trihalides ($BX_3$) structure

Monomeric, trigonal planar molecules with $sp^2$ hybridization and a vacant $2p$ orbital on the boron atom.

Lewis acidity trend of Boron halides

The relative strength of the halides as Lewis acids, which follows the order: BF_3 < BCl_3 < BBr_3 < BI_3.

$\pi$-backbonding

The donation of lone pairs from a halogen into the empty $p$-orbital of Boron, which is most effective in Fluorine and explains the counter-intuitive Lewis acidity trend in boron trihalides.

$$AlF_3$$

A Group 13 halide that is primarily ionic with a high-melting-point 3D lattice structure.

Aluminium halide dimers ($Al_2X_6$)

Species such as $AlCl_3$ and $AlBr_3$ that exist as dimers in the gas phase or non-polar solvents, featuring $sp^3$ hybridized Al atoms and bridging halogens formed by dative covalent bonds.

Frustrated Lewis Pair (FLP)

A combination of a strong Lewis acid and a strong Lewis base that cannot form a stable adduct because of steric hindrance.

FLP Main Group Catalysis

The ability of Frustrated Lewis Pairs to heterolytically cleave $H_2$ and catalyze hydrogenations, performing functions typically reserved for transition metals.

Thallium ($Tl$) toxicity

A highly toxic property resulting from the element's ability to mimic Potassium ($K^+$) ions in the body, disrupting essential biological processes.

$$Al_2O_3$$

The protective oxide layer that forms on Aluminium, providing resistance against further corrosion.

Boron applications

Used in the production of borosilicate (Pyrex) glass and as a neutron absorber in nuclear reactors.