This document discusses the nomenclature and isomers of coordination complexes. It begins by defining ligands and describing systems for naming complexes based on the central metal ion, ligands, and ligand coordination. It then describes three types of isomers that can occur in complexes: structural isomers which have different ligands, linkage isomers which have the same ligands bonded differently, and stereoisomers which have the same ligands in different spatial arrangements. The remainder of the document outlines crystal field theory and ligand field theory to explain electron configurations, orbital splitting patterns, and spectroscopic properties of transition metal complexes based on the geometry and ligand type.