Anionic triazacyclononanes: new supporting ligands in main group and transition metal organometallic chemistry

In the course of developing new ligands to support chemistry with main-group, transition and lanthanide elements, a number of research groups have focused attention on functionalized triazacyclononanes; this article provides a summary of the more recent findings with an emphasis on the organometallic chemistry of one particular class of tacn ligands, namely those involving the anionic tacn moiety.