《Dynamics and Structural Diversity of Li+(Crown Ether) Supramolecular Cations in Electrically Conducting Salts》 was written by Sambe, Kohei; Hoshino, Norihisa; Takeda, Takashi; Nakamura, Takayoshi; Akutagawa, Tomoyuki. Quality Control of 1,4,7,10,13-Pentaoxacyclopentadecane And the article was included in Journal of Physical Chemistry C in 2020. The article conveys some information:
Li+([12]crown-4)2(TCNQ)2 (1), Li+([15]crown-5)(TCNQ)2 (2a and 2b), and Li+([18]crown-6)(TCNQ)2·(H2O)2 (3) salts (TCNQ = 7,7,8,8-tetracyano-p-quinodimethane) were prepared and examined in terms of crystal structures, dielec. constants, magnetic susceptibilities, and elec. conductivities. The dynamic behavior of the small Li+ was easily activated inside the cavities of [15]crown-5 and [18]crown-6. In salt 2a, a structural phase transition at 160 K is thermally activated by a change in the -CN···Li+···NC- coordination from an asym. to a sym. environment. The phase-transition temperature for salt 2a is ∼25 K lower than that for the isostructural Na+([15]crown-5)(TCNQ)2, indicating that the behavior of Li+ inside the [15]crown-5 cavity is considerably more dynamic than that of Na+ in the same situation. Crystal polymorphs 2a and 2b are observed for Li+([15]crown-5) supramol. cations, where the two-dimensional intermol. interactions of TCNQs in salts 2a and 2b are constructed by the spanning-overlap mode of the π-dimers and π-tetramers, resp. The packing periodicity in the latter salt is twice that in the former, and this structural difference prevents the structural phase transition for salt 2b. In salt 3, the orientational disorder of Li+ inside the cavity of the [18]crown-6 is a combination of the dynamic behavior of Li+ itself and that of Li+-coordinated polar H2O mols., which are evidenced by two types of dielec. relaxation. Li+ is considerably smaller than Na+, allowing it to form a dynamic Li+···O coordination environment. The experimental part of the paper was very detailed, including the reaction process of 1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5Quality Control of 1,4,7,10,13-Pentaoxacyclopentadecane)
1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5) is a member of crown ether Ligands. Crown-ethers are macrocyclic polyethers capable of forming host-guest complexes, especially with inorganic and organic cations. Crown-ethers can incorporate protonated primary amine compounds by formation of ion-dipole bonds with the oxygen atoms of the chiral selector. Crown-ethers have been widely used for the separation of several pharmaceuticals both in aqueous and non-aqueous media. Quality Control of 1,4,7,10,13-Pentaoxacyclopentadecane
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem