Monodentate ligands are Lewis bases that donate a single pair ("mono") of electrons to a metal atom. Monodentate ligands can be either ions (usually anions) or neutral molecules.
|Some Monodentate Ligands|
|ligand||Lewis structure||name||ligand||Lewis structure||name|
|F-||fluoride ion||Cl-||chloride ion|
|Br-||bromide ion||I-||iodide ion|
|OH-||hydroxide ion||CO||carbon monoxide|
|CN-||cyanide ion||SCN-||thiocyanate ion|
Chemists often represent ligands as spheres for simplicity, even though the "sphere" sometimes has three-dimensional structure of its own. For example, when chemists draw the structure for [Ni(NH3)6]2+, each ammonia ligand is represented as a sphere. The sphere represents the donor atom of the ligand. In [Ni(NH3)6]2+, the donor atoms are the nitrogen atoms of the NH3 ligands (NOT the hydrogen atoms).
Note: only the donor atoms (N atoms) of the NH3 ligands are shown.
Note: all atoms are shown.
Used in some brands of waterbed conditioners to inhibit the growth of fungi and bacteria. Note the square planar structure.
Used as a catalyst in the Monsanto Process for making acetic acid. Note the square planar structure.