Ligand and coordination sphere

[Marina Souliman 1K]

I'm still kind of confused on what ligands actually are. What defines a ligand and what is their role in a compound? Also, what are we supposed to understand in terms of the coordination sphere?

[Mohamad Farhat 1L]

Ligands are ions or neutral molecules that bond to a central metal atom or ion. Ligands act as Lewis bases (electron pair donors), and the central atom acts as a Lewis acid. Ligands have at least one donor atom with an electron pair used to form covalent bonds with the central atom.

[Jada Larson 1F]

Coordination compounds consist of a central metal atom, usually a transition metal with may oxidation states, that is directly bonded to one or more atoms, called ligands. The coordination sphere is made from the ligand(s) directly attached to the central atom or ion.