Class 12

Organometallic Compounds Organometallic compounds are those compounds which contain one or more metal-carbon bonds. All the compounds containing carbon and a metal atom are not organometallic. We use this term for compounds which contain at least one M-C bond. For example An alkoxide such as (C3H7O4)Ti is not considered to be an organometallic compound because the … [Read more...] about Organometallic Compounds

Metal Carbonyls There is another important class of coordination compound known as metal carbonyls in which carbon monoxide (CO) acts as ligand. These are also called homoleptic carbonyls (compounds containing carbonyl ligands only). These compounds contain both σ and π character. These are formed by many transition metals. Structure of Metal Carbonyls Homoleptic binary … [Read more...] about Metal Carbonyls

Methods of preparation of Coordination Compounds Coordination compounds are generally prepared by common methods such as substitution reactions, redox reactions and by the direct combination of the reactants.  (1) Substitution reactions The majority of complexes are prepared by substitution reactions. The general method of synthesis is to replace water molecules … [Read more...] about Method of Preparation and Importance of Coordination Compounds

Stability Of Coordination compounds in Solution The stability of a complex in solution means the degree of association between the metal ion and the ligands involved in the state of equilibrium. The magnitude of the (stability or formation) equilibrium constant for the association express quantitatively the stability. For example: The formation of [Cu(NH3)4]2+  complex may … [Read more...] about Stability of Coordination Compounds in Solution

Crystal Field Theory Crystal field theory is based on the assumption that the metal ion and the ligands act as point charges and the interactions between them are purely electrostatic. In negative ligands (anions such as Cl‾, Br‾, CN‾), the interactions with metal ions are ion-ion interactions. If the ligands are neutral molecules (such as NH3, H2O, CO), the interactions … [Read more...] about Crystal Field Theory

Bonding In Coordination Compounds Valence Bond Theory For Bonding In Coordination Compounds The Main Assumptions of this Theory are listed below : (1) The central metal ion in the complex makes available a number of empty orbitals for the formation of coordination bonds with suitable ligands. The number of empty orbitals made available for this purpose is equal to … [Read more...] about Valence Bond Theory For Bonding In Coordination Compounds

Isomerism Two or more compounds having the same molecular formula but different arrangement of atoms are called isomers and the phenomenon is called isomerism. Because of different arrangement of atoms, isomers differ in one or more physical or chemical properties. Isomers can be broadly classified into two major categories : (A) Structural isomers (B) … [Read more...] about Isomerism in Coordination Compounds

IUPAC Nomenclature of Coordination Compounds Rules for Writing Formula The formula of a compound is a shorthand method used to provide basic information about the constitution of a compound in a concise and convenient manner. (1) The formula of the cation whether simple or complex is written first followed by that of the anion. (2) The coordination entity is written … [Read more...] about IUPAC Nomenclature of Coordination Compounds

Terms used in Coordination compounds Coordination Entity or Complex lon A coordination entity constitutes a central metal atom or ion bonded to a fixed number of oppositely charged ions or neutral molecules.  For example : [CoCl3(NH3)3] is a coordination entity, in which the cobalt (+3) ion is surrounded by three ammonia molecules and three negatively charged chloride … [Read more...] about Terms used in Coordination compounds

Werner's Coordination Theory Alfred Werner a Swiss chemist, in 1892 prepared a large number of coordination compounds and studied their physical, chemical and isomeric behaviour by simple experimental techniques. He isolated cobalt compounds from the reaction of cobalt chloride and ammonia. The earlier studies of cobalt complexes were precipitation reactions, conductance … [Read more...] about Werner’s Coordination Theory