1,4,7-Trithiacyclononane, also called 9-ane-S3, is the heterocyclic compound

Heterocyclic compound

A heterocyclic compound is a cyclic compound which has atoms of at least two different elements as members of its ring. The counterparts of heterocyclic compounds are homocyclic compounds, the rings of which are made of a single element....

 with the formula (CH₂CH₂S)₃. This cyclic thioether

Thioether

A thioether is a functional group in organosulfur chemistry with the connectivity C-S-C as shown on right. Like many other sulfur-containing compounds, volatile thioethers have foul odors. A thioether is similar to an ether except that it contains a sulfur atom in place of the oxygen...

 is most often encountered as a tridentate ligand

Ligand

In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...

 in coordination chemistry.

9-ane-S3 forms complexes with many metal ions, including those considered hard

HSAB theory

The HSAB concept is an acronym for 'hard and soft acids and bases. Also known as the Pearson acid base concept, HSAB is widely used in chemistry for explaining stability of compounds, reaction mechanisms and pathways....

, such as copper(II) and iron(II). Most of its complexes have the formula [M(9-ane-S3)₂]²⁺ and are octahedral.

Synthesis

This compound was first reported in 1977, and the current synthesis entails the assembly within the coordination sphere

Coordination sphere

In coordination chemistry, the coordination sphere refers to a central atom or ion and an array of molecules or anions, the ligands, around.Molecules that are attached noncovalently to the ligands are called the second coordination sphere....

of a metal ion followed by decomplexation: