Synthesis, complexation, and fluorescence behavior of 3,4-dimethylthieno[2,3-b]thiophene carrying two monoaza-15-crown-5 ether groups was written by Wu, Yong-Xiang;Cao, Jing;Deng, Hai-Yan;Feng, Jun-Xiang. And the article was included in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy in 2011.COA of Formula: C10H21NO4 This article mentions the following:
A novel fluoroionophore I based on 3,4-dimethylthieno[2,3-b]thiophene bearing two monoaza-15-crown-5 ethers at the 3- and 4-positions was prepared UV-vis and fluorescence responses of compound I upon the addition of alkali and alk. earth metal cations were evaluated in acetonitrile solution Receptor I showed a unique response for Ba2+ due to the formation of an intramol. sandwich complex. In the experiment, the researchers used many compounds, for example, 1,4,7,10-Tetraoxa-13-azacyclopentadecane (cas: 66943-05-3COA of Formula: C10H21NO4).
1,4,7,10-Tetraoxa-13-azacyclopentadecane (cas: 66943-05-3) belongs to ethers. Ether is less polar than esters, alcohols or amines because of the oxygen atom that is unable to participate in hydrogen bonding due to the presence of bulky alkyl groups on both sides of the oxygen atom. 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).COA of Formula: C10H21NO4
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem