Voltammetric study of the boric acid-salicylaldehyde-H-acid ternary system and its application to the voltammetric determination of boron.

The ternary system of boric acid, salicylaldehyde (SA) and H-acid (HA) was voltammetrically studied from kinetic and equilibrium points of view. The effect of the SA substituents was also studied by using two analogs, 5-fluorosalicylaldehyde (F-SA) and 5-methylsalicylaldehyde (Me-SA). The three cathodic peaks of Azomethine H (AzH), Azomethine H-boric acid complex (AzB), and free SA were observed in the solution containing boric acid, SA and HA.

Thermodynamics of complexation reactions of borate and phenylboronate with diol, triol and tetritol.

In order to fully elucidate the structures and stabilities of borate and phenylboronate complexes with polyols, the complexations with 1,2-ethanediol, 1,3-propanediol, 1,2,3-propanetriol, erythritol and threitol were investigated by NMR spectroscopy and DFT calculations. For the borate, 1 : 1 complexes binding with a ligand in a monodentate manner and 1 : 2 complexes binding with one ligand in an α,β- or α,γ-bidentate manner and the other in a monodentate manner were identified for the first time besides the well-known 1 : 1 and 1 : 2 complexes with five- and/or six-membered chelate rings. In addition, the formations of 1 : 1 α,β,δ-tridentate complexes with tetritol were confirmed.

Lithium ion solvation in room-temperature ionic liquids involving bis(trifluoromethanesulfonyl) imide anion studied by Raman spectroscopy and DFT calculations.

The solvation structure of the lithium ion in room-temperature ionic liquids 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide (EMI(+)TFSI(-)) and N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (BMP(+0TFSI(-)) has been studied by Raman spectroscopy and DFT calculations. Raman spectra of EMI(+)TFSI(-) and BMP(+)TFSI(-) containing Li(+)TFSI(-) over the range 0.144-0.

Conformational equilibrium of bis(trifluoromethanesulfonyl) imide anion of a room-temperature ionic liquid: Raman spectroscopic study and DFT calculations.

The structure of bis(trifluoromethanesulfonyl) imide (TFSI-) in the liquid state has been studied by means of Raman spectroscopy and DFT calculations. Raman spectra of 1-ethyl-3-methylimidazolium (EMI+) TFSI- show relatively strong bands arising from TFSI- at about 398 and 407 cm(-1). Interestingly, the 407 cm(-1) band, relative to the 398 cm(-1) one, is appreciably intensified with raising temperature, suggesting that an equilibrium is established between TFSI- conformers in the liquid state.

Evidence of conformational equilibrium of 1-ethyl-3-methylimidazolium in its ionic liquid salts: Raman spectroscopic study and quantum chemical calculations.

Raman spectra of liquid 1-ethyl-3-methylimidazolium (EMI+) salts, EMI(+)BF4-, EMI(+)PF6-, EMI(+)CF3SO3-, and EMI(+)N(CF3SO2)2-, were measured over the frequency range 200-1600 cm(-1). In the range 200-500 cm(-1), we found five bands originating from the EMI+ ion at 241, 297, 387, 430, and 448 cm(-1). However, the 448 cm(-1) band could hardly be reproduced by theoretical calculations in terms of a given EMI+ conformer, implying that the band originates from another conformer.