Squareplanare

Squareplanare is a term used in chemistry to describe a molecular geometry where an atom is surrounded by four ligands arranged at the corners of a square. This arrangement is a specific type of trigonal planar geometry, where the four ligands lie in a single plane, equidistant from the central atom, and at 90-degree angles to each other. In this geometry, the central atom possesses a planar configuration, and the ideal bond angles are 90 degrees. Molecules exhibiting square planar geometry often have a central metal atom bonded to four ligands. Common examples include certain transition metal complexes, such as tetrachloroplatinate(II) ([PtCl4]2-) and xenon tetrafluoride (XeF4). This geometry is distinct from tetrahedral geometry, where the four ligands are arranged in a three-dimensional pyramid with a triangular base, and from the more common square pyramidal geometry, which has a central atom with four ligands in a square plane below it and one ligand above the plane. The electronic configuration of the central atom and the nature of the ligands play a significant role in determining whether a square planar geometry is adopted. It is often observed in d8 metal complexes.