Synthesis of tris-(azacrown) ethers for carboxylic acid recognition was written by Lee, Michael;Zali-Boeini, Hassan;Li, Feng;Lindoy, Leonard F.;Jolliffe, Katrina A.. And the article was included in Tetrahedron in 2013.Formula: C10H21NO4 This article mentions the following:
The synergistic enhancement of metal ion extraction by azacrown ethers in the presence of carboxylic acids has been attributed to a ligand assembly effect in which these two ligands form a complex, facilitated by proton transfer, prior to complexation of the metal ion. In order to investigate the first steps in this multi-component complexation procedure, six tris-(azacrown) ethers I [n = 1, 2; R = H, Me, Et] were synthesized in high yields and their ability to complex mono- and tri-carboxylic acids was investigated by 1H NMR in methanol-d4. All six compounds bound to benzoic acid with 1:3 host-guest stoichiometry and four of them bound tricarboxylic acids with 1:1 host-guest stoichiometry, providing good support for the proposed first step in the ligand assembly effect. In the experiment, the researchers used many compounds, for example, 1,4,7,10-Tetraoxa-13-azacyclopentadecane (cas: 66943-05-3Formula: C10H21NO4).
1,4,7,10-Tetraoxa-13-azacyclopentadecane (cas: 66943-05-3) belongs to ethers. Of all the functional groups, ethers are the least reactive ones. Ether bonds are quite stable towards bases, oxidizing agents and reducing agents. Electron-deficient reagents are also stabilized by ethers. For example, borane (BH3) is a useful reagent for making alcohols. Pure borane exists as its dimer, diborane (B2H6), a toxic gas that is inconvenient and hazardous to use. Borane forms stable complexes with ethers, however, and it is often supplied and used as its liquid complex with tetrahydrofuran (THF).Formula: C10H21NO4
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem