Coordination compounds are those addition molecular compounds which retain their identity in solid state as well as in dissolved state. In these compounds . the central metal atom or ion is linked by ions or molecules with coordinate bonds. e.g., Potassium ferrocyanide, K4 [Fe(CN)6]. Coordination Compounds - Introduction, Important Terms, Properties, Classification, Ligands, IUPAC Nomenclature, Isomerism and Applications in Chemistry : Definition ... Coordination compounds are a special class of compounds in which the central metal atom is surrounded by ions or molecules beyond their normal valency. These are also referred to as complex compounds . These compounds are called Coordination compounds . Many biologically important compounds are coordination compounds in which complicated organic species are bound to metal ions. The common examples are : haemoglobin which is a coordination compound of iron, chlorophyll which is a coordination ...