Complexation of Macrocyclic Compounds with Nicotinamide in Dimethylsulphoxideand its Water Mixture was written by Kotkar, Rahul M.;Srivastava, Ashwini K.. And the article was included in Supramolecular Chemistry in 2008.COA of Formula: C10H21NO4 This article mentions the following:
The complexation behavior of nicotinamide with macrocyclic polyethers viz, 15-crown-5, benzo-15-crown-5, 18-crown-6, dicyclohexano-18-crown-6, dibenzo-18-crown-6, dibenzo-24-crown-8, 1,4,7,10,13,16-hexathiacyclooctadecane, monoaza-15-crown-5, 1,4,10-trioxa-7,13-diaza-cyclopentadecane, 5,6,14,15-dibenzo-1,4-dioxa-8,12-diazacyclopentadecane, 7,16-dibenzyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane, 1,4,7-tritosyl-1,4,7-triazacyclononane, 1,4,7,10-tetratosyl-1,4,7,10-tetraazacyclododecane and 1,4,8,11-tetraazacyclooctadecane has been studied in dimethylsulfoxide (DMSO) and 90% DMSO + water using differential pulse polarog. and complexation constants have been reported. Nicotinamide forms stable complexes with six-membered coronand rings of the crown ethers. The nature of the atoms (oxygen, sulfur and nitrogen) in the coronand ring is observed to affect the stability of the complex. The stoichiometry and stability constants of the complexes were determined by monitoring the shifts in peak potentials of the polarograms of nicotinamide against the ligand concentration The Gibbs free energy change turns out to be neg. at 25°, which indicates the spontaneity of the binding of nicotinamide with crown ethers. The mole ratio of nicotinamide to the macrocyclic compound was also determined and it was found that the complexes were of 1:1 type with respect to crown ethers. The tendency of nicotinamide to form complexes with macrocycles is found to be greater in DMSO than in DMSO + water. 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. Of all the functional groups, ethers are the least reactive ones. Ether bonds are quite stable towards bases, oxidizing agents and reducing agents. But on the other hand, ethers undergo cleavage by reaction with acids. Ethers feature bent C–O–C linkages. In dimethyl ether, the bond angle is 111° and C–O distances are 141 pm. The barrier to rotation about the C–O bonds is low. The bonding of oxygen in ethers, alcohols, and water is similar. In the language of valence bond theory, the hybridization at oxygen is sp3.COA of Formula: C10H21NO4
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem