coordination complex

Examples of coordination complex in the following topics:

• Reactions of Coordination Compounds

  • In chemistry, a coordination or metal complex consists of an atom or ion (usually metallic) and a surrounding array of bound molecules or anions known as ligands or complexing agents.
  • Many metal-containing compounds consist of coordination complexes.
  • These complexes are called chelate complexes, the formation of which is called chelation, complexation, and coordination.
  • A common reaction between coordination complexes involving ligands are electron transfers.
  • This complex, PtCl2(NH3)2, is an anti-tumor drug and an example of a coordination complex.

• Biomolecules

  • Coordination complexes are found in many biomolecules, especially as essential ingredients for the active site of enzymes.
  • Coordination complexes (also called coordination compounds) and transition metals are widespread in nature.
  • While there are other biologically relevant molecules that also contain metals, coordination complexes contain a central metal ion and are important in many biological processes.
  • Metalloenzymes contain a metal ion bound to the protein with one labile coordination site.
  • The fourth coordination site is occupied by a water molecule.

• Metal Cations that Act as Lewis Acids

  • Ligands create a complex when forming coordinate bonds with transition metals ions; the transition metal ion acts as a Lewis acid, and the ligand acts as a Lewis base.
  • The number of coordinate bonds is known as the complex's coordination number.
  • The product is known as a complex ion, and the study of these ions is known as coordination chemistry.
  • One coordination chemistry's applications is using Lewis bases to modify the activity and selectivity of metal catalysts in order to create useful metal-ligand complexes in biochemistry and medicine.
  • Examples of several metals (V, Mn, Re, Fe, Ir) in coordination complexes with various ligands.

• Coloring Agents

  • The electronic configuration of some metal complexes gives them important properties, such as color in coordination compounds.
  • Many of the properties of metal complexes are dictated by their electronic structures.
  • It can explain complexes in which the interactions are covalent.
  • Changing the metal or the ligand can change the color of the coordination complex.
  • Reactions starting from NiCl2·6H2O can be used to form a variety of nickel coordination complexes because the H2O ligands are rapidly displaced by ammonia, amines, thioethers, thiolates, and organophosphines.

• Coordination Number, Ligands, and Geometries

  • The coordination number determines the number of ligands attached to the central ion and the overall shape of the complex.
  • Typically the chemistry of complexes is dominated by interactions between s and p molecular orbitals of the ligands and the d orbitals of the metal ions.
  • In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex.
  • For example, trans-spanning ligands are bidentate ligands that can span coordination positions on opposite sides of a coordination complex.
  • Calculate the coordination number of the metal in a coordination complex.

• Octahedral Complexes

  • When two or more types of ligands are coordinated to an octahedral metal center, the complex can exist as isomers.
  • In an octahedral complex, this degeneracy is lifted.
  • Rearrangements where the relative stereochemistry of the ligands change within the coordination sphere
  • Many reactions of octahedral transition metal complexes occur in water.
  • Discuss the degeneracy of the d orbitals in an octahedral metal complex.

• Isomers in Coordination Compounds

  • Coordination stereoisomers have the same bonds in different orientations; structural isomers have different bonding orientations.
  • As with other compounds, there are several kinds of coordination complex isomers.
  • In cis molecules, the two ligands are on the same side of the complex.
  • In coordination isomerism, both positive and negative ions of a salt are complex ions and the two isomers differ in the distribution of ligands between the cation and the anion.
  • Explain the effect of isomerization on the properties of a coordination complex.

• Magnetic Properties

  • Metal complexes that have unpaired electrons are magnetic.
  • Considering only monometallic complexes, unpaired electrons arise because the complex has an odd number of electrons or because electron pairing is destabilized.
  • Ti(II), with two d electrons, forms some complexes that have two unpaired electrons and others with none.
  • As an example, Fe prefers to exist as Fe3+ and is known to have a coordination number of six.
  • Discuss the correlation between the electronic structure of a coordination complex and its magnetic properties.

• Chelating Agents

  • Chelating agents are ligands for metals that bind via multiple atoms, thus taking up several coordination sites on the metal.
  • Chelation is the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central atom.
  • Chelate complexes are contrasted with coordination complexes composed of monodentate ligands, which form only one bond with the central atom.
  • Chelating agents, unlike the other ligands in coordination compounds, bind via multiple atoms in the ligand molecule, not just one.
  • In (1), the bidentate ligand ethylenediamine forms a chelate complex with the copper ion.

• Naming Coordination Compounds

  • A typical complex is bound to several donor atoms, which can be the same or different.
  • Coordination refers to the coordinate covalent bonds (dipolar bonds) between the ligands and the central atom.
  • When naming a complex ion, the ligands are named before the metal ion.
  • The complex ion, an anion, is inside the parentheses.
  • Identify the proper name for a coordination complex given its molecular formula.