Thermodynamic Studies of Cation-Macrocycle Interactions in Nickel Pincer-Crown Ether Complexes Enable Switchable Ligation was written by Smith, Jacob B.;Kerr, Stewart H.;White, Peter S.;Miller, Alexander J. M.. And the article was included in Organometallics in 2017.Computed Properties of C10H21NO4 This article mentions the following:
The thermochem. of cation-macrocycle interactions in Ni pincer complexes bearing hemilabile aza-15-crown-5 or aza-18-crown-6 macrocycles was studied and applied to cation-controlled reversible ligand binding. Cation-crown interactions were examined in a noncoordinating, low polarity solvent (CH2Cl2) and a coordinating, polar solvent (acetonitrile). Structural studies provide solid-state information on cation-crown interactions, while binding affinity studies in solution provide quant. thermodn. information. The different hemilabile ligand coordination modes have vastly different cation binding affinities, with the tridentate pincer coordination mode binding cations >100,000 times more strongly than the tetradentate coordination mode with a crown ether O donating to Ni. CH2Cl2 enforces strong cation-crown interactions without disrupting the hemilabile ether ligand, whereas MeCN disrupts hemilability by displacing the ethers from the Ni center and supports weaker cation-crown interactions. In CH2Cl2, Li binding provides at least 7 kcal mol-1 of stabilization to assist in ligand binding, and the extent of stabilization can be tuned by the choice of cation. The newfound thermodn. insight guided the development of in situ switchable ligand binding and release at Ni using cations. The Ni complex only binds pentafluorophenylnitrile upon addition of Li+ salts in CH2Cl2, and the nitrile ligand is readily released upon sequestration of the Li+ with 12-crown-4. In the experiment, the researchers used many compounds, for example, 1,4,7,10-Tetraoxa-13-azacyclopentadecane (cas: 66943-05-3Computed Properties of 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. Ethers can form hydrogen bonds with other molecules (alcohols, amines, etc.) that have O―H or N―H bonds. The ability to form hydrogen bonds with other compounds makes ethers particularly good solvents for a wide variety of organic compounds and a surprisingly large number of inorganic compounds.Computed Properties of C10H21NO4
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem