Pauling’s Rules: A Guide to Coordination Polyhedra. “Pauling’s Rules: As a function of the sum of the cation and anion radii, calculate the maximum cation to cation separation that occurs for coordination polyhedra sharing vertices, edges or faces for (a) cubic, (b) octahedral, and (c) tetrahedron coordinations.”

Pauling’s Rules: A Guide to Coordination Polyhedra

Linus Pauling, an American chemist and winner of two Nobel Prizes, developed a set of rules for understanding the structures and properties of coordination polyhedra. Pauling’s Rules, as they are known, are used to predict the maximum cation-to-cation separation that occurs for coordination polyhedra sharing vertices, edges or faces. This is done as a function of the sum of the cation and anion radii for (a) cubic, (b) octahedral, and (c) tetrahedral coordination (Thompson, 2017). Pauling’s Rules are based on the assumption that the cations and anions in a coordination polyhedron will be packed as closely together as possible. This is because the cations and anions in a coordination polyhedron are held together by electrostatic attraction forces, and the closer they are together, the stronger these forces are. According to Pauling’s Rules, the maximum cation-to-cation separation is calculated by adding the cation and anion radii together and then subtracting the sum from the sum of the cation and anion radii (R) (Thompson, 2017). Cont…