Monodentatc ligands

IR-spectral and conductivity data indicate that in chloroform solution diphenyl tellurium diperchlorate has monodentate, covalently bonded perchlorate groups. The complexes with one monodentatc ligand behave as 1 1 electrolytes1 in acetonitrile and acetone, while, the complexes with two monodentate ligands or one bidentate ligand behave as 1 2 electrolytes2. 

A ligand that can form one bond to a metal ion is called a monodentatc ligand, or a unidentate ligand (from root words meaning one tooth ). Examples of unidentate ligands are shown in Table 20.13. 

Similar to triphenylphosphine, the tris(2-cyanoethyl)phosphine (cep) forms complexes with technetium in which cep is a monodentatc ligand. Reaction of TcOi in aqueous ethanolic solution containing hydrochloric acid yielded a blue, microcrystal-linc solid of [TcCl4(cep)2]° with a melting point of 175 °C [303]. 

---