replacing the nitrogen donor of a Tp ligand atoms with sulfur atoms, a class of ligands known as Tm can be made. These are related to the thioureas.¹; Several research groups including Anthony F. Hill's group have been working on this ligand class. To form NaTm {Na+ HB(mt)3−), Methimazole and sodium borohydride are heated together. Coordination chemistry with ruthenium, rhodium, osmium, molybdenum, tungsten, and other metals has been reported. 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. Another variation is the Trisoxazolinylborate ligand. 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). See also Pincer ligands References Further reading Examples of Scorpionate ligands Inorganic Chemistry, 43(24), 7800–7806. Inorganic Chemistry, 43(26), 8212-8214. Chemical Reviews, 102, 1851-1896. Inorganic Chemistry, 42(24), 7978-7989. Journal of the American Chemical Society, 126, 1330-1331. Inorganic Chemistry, 44(4), 846-848. Organometallics, 23, 1200-1202. Acta Crystallographica Section C, 69, part 9 (2013) special issue on scorpionates. External links Chemical & Engineering News, Pinch and Sting: The Scorpionates, April 28, 2003. Coordination chemistry Tripodal ligands