Development of cation/anion 'interaction' scales for ionic liquids through ESI-MS measurements

Autor: Daniela Pieraccini, Olga Bortolini, Tiziana Siciliano, Cinzia Chiappe, Riccardo Bini
Rok vydání: 2007
Předmět:
Zdroj: The journal of physical chemistry. B. 111(3)
ISSN: 1520-6106
Popis: Electrospray ionization mass spectrometry applied to ionic liquids allowed the study of loosely bonded supramolecules, originating from these organic salts. Based on the observation that ionic liquids formed cationic [C(q+1)X(q)](+) and anionic [C(q)X(q+1)](-) supramolecular aggregates, we have investigated mixed networks, formed by different cations coordinated to a selected anion or by different anions bonded to a given cation, i.e., [C1...X...C2](+) and [X1...C...X2](-), with the aim to build a scale of the cation-anion interaction strength. The qualitative order of intrinsic bond strength to Br- was found to be the following: [emim](+)[bmim](+)[mor1,2](+)[hmim]+[omim](+)[mor1,4](+)[bupy](+)[bpyrr](+)[picol](+)[bm(2)im](+)[TBA](+). Similarly, the interaction energies to 1-butyl-3-methylimidazolium (bmim) species envisaged two classes of anions: species tightly coordinated to the cationic moiety that include CF3COO(-), Br(-), N(CN)2(-), and BF4(-) and anions loosely interacting with the alkylimidazolium species such as OTf(-), PF6(-), and Tf2N(-).
Databáze: OpenAIRE