2016-36-6Relevant articles and documents
Choline salicylate ionic liquid by X-ray scattering, vibrational spectroscopy and molecular dynamics
Tanzi, Luana,Nardone, Michele,Benassi, Paola,Ramondo, Fabio,Caminiti, Ruggero,Gontrani, Lorenzo
, p. 39 - 49 (2016)
We report here a combined experimental and theoretical study on the bio-compatible salicylate choline ionic liquid. The liquid structure has been investigated by X-ray diffraction and vibrational (IR and Raman) spectroscopy. Local structure has been obtained from ab initio calculations on static ion pairs and from dynamic simulations of a small portion of the liquid. The theoretical models indicate that salicylate is connected by hydrogen bonding to choline mainly through the carboxylate group and forms stable ion pairs. A strong intramolecular interaction hinders internal rotations of the OH group of salicylate and competes with the hydrogen bonding with choline. When the liquid has been simulated by classical force fields we found a good agreement with the X-ray experimental features, comparable to that obtained from AIMD simulations. Important insights on hydrogen bonding between carboxylate and choline have been also derived from the analysis of the CO stretching modes of carboxylate measured in the Raman and IR spectra and calculated from VDOS-Wannier centers procedures.
Polyethylene glycol derivatization of the non-active ion in active pharmaceutical ingredient ionic liquids enhances transdermal delivery
Zavgorodnya, Oleksandra,Shamshina, Julia L.,Mittenthal, Max,McCrary, Parker D.,Rachiero, Giovanni P.,Titi, Hatem M.,Rogers, Robin D.
, p. 1499 - 1508 (2017/02/23)
We report the synthesis of four salts composed of the salicylate anion ([Sal]?) paired with tributylammonium ([HN444]+), choline ([Cho]+), 1-methylpyrrolidinium ([HMPyrr]+), and triethylene glycol monomethyl ether tributylammonium ([mPEG3N444]+) cations. Three of the synthesized salts (room temperature liquids [mPEG3N444][Sal] and [Cho][Sal], and a supercooled liquid [HN444][Sal]) belong to the category of ionic liquids (ILs), and one salt (solid [HMPyrr][Sal]) was a crystalline solid. ILs in their neat form were studied for membrane transport through a silicon membrane, and exhibited higher transport compared to a control experiment with sodium salicylate dissolved in mPEG3OH as solvent, but lower membrane transport compared to salicylic acid dissolved in mPEG3OH. The ‘PEGylated’ IL, [mPEG3N444][Sal], crossed the membrane with an ca. ～2.5-fold faster rate than that of any of the non-PEGylated ILs. This work demonstrates not only that API-ILs can eliminate the use of a solvent vehicle during application and notably transport through a membrane as opposed to a higher melting crystalline salt, but also that the membrane transport can be further enhanced by PEGylation of the counter ions.
Highly luminescent and color-tunable salicylate ionic liquids
Campbell, Paul S.,Yang, Mei,Pitz, Demian,Cybinska, Joanna,Mudring, Anja-Verena
, p. 4704 - 4712 (2014/05/06)
High quantum yields of up to 40.5 % can be achieved in salicylate-bearing ionic liquids. A range of these ionic liquids have been synthesized and their photoluminescent properties studied in detail. The differences noted can be related back to the structure of the ionic liquid cation and possible interionic interactions. It is found that shifts of emission, particularly in the pyridinium-based ionic liquids, can be related to cation-anion pairing interactions. Facile and controlled emission color mixing is demonstrated through combining different ILs, with emission colors ranging from blue to yellow. Brilliant liquids: Highly photoluminescent salicylate ionic liquids (ILs) were synthesized and characterized. Quantum efficiencies up to 40.5 % were achieved. The optical properties are related to cation-anion pairing interactions. Facile controlled emission color mixing was demonstrated by combining different ILs, with emission colors ranging from blue to yellow (see figure).
