Other
A range of tripodal phosphines such as HC(CH2PR2)3, N(CH2CH2PPh2)3 and P(CH2CH2PMe2)3 have been reviewed.
The tetra amine (tris-(2-aminoethyl) amine) can be reacted with salicylaldehyde to form a ligand which can bind with three oxygens and three nitrogens to a metal.
Trispyrazolylmethane (Tpm) is another class of scorpionate ligands, notable for having identical geometry and very similar coordination chemistry to Tp with only a difference in charge between them.
Hydrotris(pyrazolyl)aluminate (Tpa) complexes have similar coordination geometries to Tp complexes, however Tpa ligands are more reactive due to the weaker Al-N and Al-H bonds, compared to B-N and B-H bonds of Tp ligands, which results in either Tpa ligand transfer, pyrazolate transfer, or hydride transfer with MX2 (M = Mg, Mn, Fe, Co, Ni, Cu, Zn; X = Cl, Br).
Read more about this topic: Scorpionate Ligand