1,4,7-Trimethyl-1,4,7-triazacyclononane is the

aza-crown ether In organic chemistry, an aza-crown ether is an aza analogue of a crown ether (cyclic polyether). That is, it has a nitrogen atom (amine linkage, or ) in place of each oxygen atom (ether linkage, ) around the ring. While the parent crown ethers ...

with the formula (CH₂CH₂NCH₃)₃. This colorless liquid is the N-methylated derivative of

triazacyclononane 1,4,7-Triazacyclononane, known as "TACN" which is pronounced "tack-en," is an aza-crown ether with the formula (C2H4NH)3. TACN is derived, formally speaking, from cyclononane by replacing three equidistant CH2 groups with NH groups. TACN is one of ...

(TACN), a face-capping

tridentate ligand A tridentate ligand (or terdentate ligand) is a ligand that has three atoms that can function as donor atoms in a coordination complex. Well-known tridentate ligands include diethylenetriamine with three nitrogen donor atoms, and the iminodiaceti ...

that is popular in

coordination chemistry A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ' ...

. Although TACN is known for forming 2:1 "sandwich" complexes with many metal ions, corresponding 2:1 complexes of Me₃TACN are only known for Ag⁺, Na⁺, and K⁺. This effect is mainly due to the greater bulk of Me₃TACN, which requires ions with a larger ionic radius to accommodate two ligands. Several related derivatives have been prepared with diverse substituents on nitrogen.

References

{{DEFAULTSORT:Trimethyl-1,4,7-triazacyclononane, 1,4,7- Polyamines Chelating agents Macrocycles Heterocyclic compounds with 1 ring Tertiary amines Nine-membered rings Tridentate ligands