Bridging ligand

When describing coordination complexes care should be taken not to confuse μ with η ('eta'), which relates to hapticity.

chem2|Cp2Mo2(SH)2S2}} Many simple organic ligands form strong bridges between metal centers.

Many common examples include organic derivatives of the above inorganic ligands (R = alkyl, aryl): OR−, SR−, NR−2, NR2− (imido), PR−2 (phosphido, note the ambiguity with the preceding entry), PR2− (phosphinidino), and many more.

Computational studies suggest that metal-metal bonding is absent in many compounds where the metals are separated by bridging ligands.

Several organophosphorus ligands have been developed that bridge pairs of metals, a well-known example being Ph2PCH2PPh2.