Question

Why is AX4 tedreahedral rather than square planar? Use pictures and bond angeles in explanation

Answer 1

Answer – We know when the central atom has 4 substituents then there is geometry either tetrahedral or square planar.

We also know the tetrahedral geometry is common for the complexes which has electronic configuration d^o or d¹⁰. In the tetrahedral geometry all four bond are the same with bond angle approximately 109.5^o. The metal which has the electronic configuration d^o or d¹⁰ those one has geometry is widespread and each group has same distance. There are 4 groups are freely placed in order to free steric hindrance with more bond angle. Tetrahedral complex the CFT diagram has the dx²-y² and dz² orbital at same energy due to the little repulsion and orbital are between the ligand axis.

In the square planar geometry there are four groups are constituent and make the corners of the square in the same plane. The square planar has the bond angle approximately 90^oC and it is less than tetrahedral geometry. The square planar geometry for the metal which has d⁸ electronic configuration and the energy of orbital are more than tetrahedral geometry, so AX₄ tedreahedral rather than square planar and the following are diagram for the tetrahedral and square planar geometry of AX₄ –