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2: Ligand Binding in Coordination Complexes and Organometallic Compounds

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    • 2.1: Introduction
    • 2.2: How Tightly Do Ligands Bind?
    • 2.3: Electron Counting in Transition Metal Complexes
    • 2.4: Chelation
      Monodentate ligands bind through only one donor atom. Bidentate ligands bind through two donor sites. Bidentate binding allows a ligand to bind more tightly. Tridentate ligands, which bind through three donors, can bind even more tightly, and so on. This phenomenon is generally called the "chelate effect".
    • 2.5: Pi Coordination- Donation from Alkenes
    • 2.6: Hapticity
      The term used to describe the participation of multiple atoms simultaneously during pi coordination is hapticity.
    • 2.7: Hard and Soft Acid and Base Concepts
      Not all metals form coordination complexes with all possible ligands. Some metals are more likely to form compounds with certain ligands. This observation has eventually led to a classification system called Hard and Soft Acids and Bases (HSAB).
    • 2.8: Ligand Field Theory
    • 2.9: Ligand Field Stabilization Energy
      We can use the relative energy levels of the d orbitals in a given complex to calculate whether the overall energy would be higher or lower in a high-spin vs. a low-spin case, for example. The calculation provides us with a value that is called the ligand field stabilization energy. Although we have been thinking of bonding in transition metal complexes in terms of molecular orbital ideas, ligand field stabilization energy actually has its roots in a separate approach called crystal field theory
    • 2.10: Spectrochemical Series
      The d orbital energy splitting is influenced by how strongly the ligand interacts with the metal. Ligands that interact only weakly produce little change in the d orbital energy levels, whereas ligands that interact strongly produce a larger change in d orbital energy levels. The spectrochemical series is a list of ligands based on the strength of their interaction with metal ions.
    • 2.11: Ligand Lability
    • 2.12: Jahn-Teller Distortion
      In some cases, the d-electron count can have a subtle influence on the geometry of a complex. For example, an octahedral complex might be distorted, either stretched along one axis or else compressed. In Jahn-Teller Distortion, this effect arises from unequally-distributed electrons in the same level (degeneracy). Although this phenomenon is structural, it can sometimes exert an influence on the stability of complexes that translates into accelerated ligand substitutions.
    • 2.13: Multiple Bonds in Coordination Complexes
    • 2.14: Solutions to Selected Problems
    • 2.15: More Solutions to Selected Problems

    This page titled 2: Ligand Binding in Coordination Complexes and Organometallic Compounds is shared under a CC BY-NC 3.0 license and was authored, remixed, and/or curated by Chris Schaller via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.

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