Ion-ion-solvent interactions in solution. 8. Spectroscopic studies of the lithium perchlorate/N,N-dimethylformamide system

Solvation of monovalent anions in acetonitrile and N,N-dimethylformamide: Parameterization of the IEF-PCM model

“…Thus, the ion-ion interactions complicate the separation of the individual ionic contributions to thermodynamic transfer functions for the electrolytes. Similar studies have been undertaken in DMF solutions of lithium and sodium perchlorate also exhibiting evidences for the existence of both, solvent shared and contact solvated ion pairs [66]. Studies on the structure of NaClO 4 solutions in DMF also furnished experimental evidences for the formation of ion pairs shared by solvent molecules.…”

Calculation of Vibrational Spectra of Coordinated Perchlorate Ion in Dipolar Aprotic Solvents

“…Table 1 presents the calculated vibrational frequencies and solvation energies of ClO with T d symmetry and solvation energies E s that were calculated by any of the three methods were practically independent of the nature of the DAS. This indicated that the anion was weakly solvated, which agreed with experimental studies of the vibrational spectrum of the anion in highly dilute LiClO 4 solutions in DAS [1][2][3][4][5][6][7][8][9][10][11][12]. The solvation energies E s , dispersion component of the solvation energy E d , and total contribution to the solvation energy of the non-electrostatic component E non-el of − 4 ClO in DAS were calculated.…”

A purely vibrational insight on the tetragonal distortion of [Cu(DMF)6]2+

“…However, ion pairs can be also formed in these solutions and cause an asymmetry in the inner-sphere of the metal ion, as reported in the literature for the LiClO 4 /DMF system [11]. Thus, the Raman spectrum of the most concentrated Cu(ClO 4 ) 2 solution was recorded at the Cl-O stretching region and shows only an intense band at 932 cm À1 accompanied by a weak signal at 911 cm À1 (Fig.…”

“…Indeed, the d OCN region shows additional bands as a Cu(II) salt is added to this solvent [13]. Curiously, new bands are also observed at this region in the presence of Li(I) and are described as molecules of DMF strongly and weakly bonded to the metal, as a consequence of not only solvated ions, but also ion-pairs which are formed in higher salt compositions and usually cause a distortion in the solvation sphere of the metal [11].…”

“…Undoubtedly, the understanding of the involved mechanisms will help us to better interpret systems containing proteins and polypeptides. In contrast, N,N-dimethylformamide (DMF) cannot be used as a model due to the lack of the -CONHgroup and the large contribution of the m CN mode to several bands, as very well documented by James and Mayes [11]. Thus, the participation of O, N or both atoms in the interaction to metals has been determined in solution from other spectroscopic techniques.…”