How does CFT help in understanding these geometries better? Tetrahedral complexes are high spin because electrons in the complex tend to go the higher energy levels instead of pairing with other electrons. Square planar complexes are low spin as electrons tend to get paired instead of remaining unpaired. Methane or CH4 has the tetrahedral geometry where the Carbon atom is in the central position of the complex. Transitions metals such as Rh(I), Ir (II), etc has square planar geometry. The configuration of the electrons in tetrahedral complexes can be from d0 or d10. The complexes forming square planar geometry has the electron configuration ending in d8. Tetrahedral complexes form a two-tiered crystal field diagram. The square planar complexes form a four-tiered diagram in CFT. The compounds having no lone pairs of electrons form a tetrahedral structure. This type of geometry is mostly prevalent in the transition metal complexes. The complexes forming a tetrahedral geometry also have the coordination number of 4. The coordination number of the complexes forming such molecular geometry is 4. The bond-angle between the ligands in the tetrahedral geometry is 109.5 degrees. The bond-angle between the atoms in the square planar geometry is 90 degrees. One atom is located at the center of the four atoms, forming a structure similar to a tetrahedron. Square planar vs Tetrahedral Square Planar Tetrahedral The square planar geometry has one central atom that is surrounded by the four constituent atoms. Now that we know how exactly the atoms are arranged in square planar and tetrahedral geometry let us go through the differences between these two geometries that can help you differentiate the shapes better. The bond angle between the ligands is higher than 90 degrees. The distribution of ligands in this geometry forms a structure similar to a pyramid, where ligands are located at every corner of the pyramid with one central atom in the middle of the structure. People tend to get confused between both these molecular geometry because both square planar and tetrahedral has the coordination number of 4. Mostly the transition metals that have the electron configuration ending in d8 form this type of molecular geometry. This distribution of atoms in the central atom’s square plane is where it gets the name “square planar.” The bonds between the atoms in this geometry are 90 degrees. The molecules that form square planar geometry have one central atom surrounded by the four constituent atoms in the corner of its square plane. There are striking differences between these molecular shapes, and understanding it better, let us first check out the arrangement of atoms in both of these molecular shapes. Still, many people struggle to understand the differences between square planar and tetrahedral geometry, as both these geometries have the same coordination number. There are many molecular shapes that are formed due to the unique distribution of the atoms in the complexes. This model aids in better understanding the metal-ligand bonds and the geometry of transition molecules. Whereas when it comes to understanding the structure of metal ions and compounds, the model of Cyrstal Field Theory ( CFT ) is used. This model is used widely to understand the covalent bonds between the nonmetal compounds in the complex. One of the commonly used models used to study the geometry of molecules is the Valence Shell Electron Pair (VSEPR) theory. One can use several theories to predict this molecular structure and understand the arrangements of the electrons in it. This electron configuration helps to determine the molecular structure and to get a three-dimensional structure of these complexes.

These molecular shapes help understand several properties of the given compound, as the arrangement of the atoms in the complex depends on the number of electron pairs in the valence shell. It is vital to be well-versed with the different types of molecular shapes to understand the geometry of the molecules.

Tetrahedral molecular geometry