Difference Between Trigonal Planar And Trigonal Pyramidal: Trigonal planar and trigonal pyramidal are two molecular geometries commonly observed in chemistry. In, trigonal planar geometry, one atom in the middle of a molecule is linked to three other atoms without any lone pairs of electrons on the central atom. In this geometry, the atoms are arranged in a flat, equilateral triangle around the central atom. In contrast, in trigonal pyramidal geometry, the center atom of a molecule is connected to three other atoms and contains a single lone pair of electrons.  The atoms are arranged in a pyramid shape, with the lone pair of electrons occupying the fourth position. The presence or absence of a lone pair of electrons on the central atom leads to different spatial arrangements of the atoms, and this can influence the molecule’s properties and reactivity.

Learn more about difference between trigonal planar and trigonal pyramidal and their basic introduction with pictorial representation in this article.

Trigonal Planar

Trigonal planar is a term used to define the geometry or arrangement of atoms in a molecule or ion in which a central atom is surrounded by three identical atoms or groups of atoms arranged at the corners of an equilateral triangle. In this geometry, the bond angles between the central atom and the three surrounding atoms are all 120 degrees, resulting in a flat and planar shape. Molecules with a trigonal planar geometry often have sp2 hybridization, which means that the central atom has three hybridized orbitals and one unhybridized p orbital. Examples of molecules with a trigonal planar geometry include boron trifluoride (BF3), formaldehyde (CH₂O), and some ions, such as the carbonate ion (CO₃^2-).

Trigonal Pyramidal

Trigonal pyramidal is a term used to describe the geometry or arrangement of atoms in a molecule or ion in which a central atom is surrounded by three identical atoms or groups of atoms and a lone pair of electrons. In this geometry, the bond angles between the central atom and the three surrounding atoms are less than 120 degrees, resulting in a three-dimensional and not planar shape.

Molecules with a trigonal pyramidal geometry often have sp3 hybridization, which means that the central atom has four hybridized orbitals. Three of the orbitals are used to form sigma bonds with the other atoms, and the fourth orbital contains the lone pair of electrons. Examples of molecules with a trigonal pyramidal geometry include ammonia (NH3), phosphine (PH3), and some ions, such as the ammonium ion (NH₄⁺). The presence of a lone pair of electrons in a trigonal pyramidal molecule can affect its polarity, reactivity, and other properties. For example, molecules with a trigonal pyramidal geometry are generally polar due to the asymmetry created by the lone pair of electrons.

The presence of a lone pair of electrons in a trigonal pyramidal molecule can affect its polarity, reactivity, and other properties. For example, molecules with a trigonal pyramidal geometry are generally polar due to the asymmetry created by the lone pair of electrons

Difference Between Trigonal Planar and Trigonal Pyramidal

The difference between trigonal planar and trigonal pyramidal is tabulated below: