A study of the polarization of water and methanol by various diamagnetic ions in an aprotic solvent
Part I. Proton Magnetic Resonance Studies on the Polarization of Water and Methanol by NaClO[subscript 4], LiClO[subscript 4], Mg(ClO[subscript 4])[subscript 2], Et[subscript 4]NClO[subscript 4], Bu[subscript 4]NI, Et[subscript 4]NBr, and Et[subscript 4]NCl in an Aprotic Solvent. The polarizat...
| Summary: | Part I. Proton Magnetic Resonance Studies on the Polarization of Water and Methanol by NaClO[subscript 4], LiClO[subscript 4], Mg(ClO[subscript 4])[subscript 2], Et[subscript 4]NClO[subscript 4], Bu[subscript 4]NI, Et[subscript 4]NBr, and Et[subscript 4]NCl in an Aprotic Solvent.
The polarization of water by NaClO[subscript 4], LiClO[subscript 4], Mg(ClO[subscript 4])[subscript 2], Et[subscript 4]NClO[subscript 4], Bu[subscript 4]NI, Et[subscript 4]NBr, and Et[subscript 4]NCl in acetone and acetonitrile has been investigated by studying the variation in the chemical shift of the water protons as a function of the salt and water concentration. The effects of cation solvation were obtained from the perchlorate salts since Et[subscript 4]NClO[subscript 4] showed no effect on the water resonance. The effects of anion polarization were obtained from the tetraalkylammonium salts.
The chemical shifts at low salt and low water concentration are analyzed. Information on solvation constants and the chemical shifts of the solvated ion-water complex are reported and discussed. The results indicate the expected dependence on ion size and charge as well as on the solvent.
Similar studies on the methanol molecule were made using acetonitrile as solvent. These studies have indicated that only one proton of the water molecules is complexed in the anion-water complex.
The experimentally-determined polarization shifts of the OH proton in the various ion complexes of water and methanol are discussed in terms of the electric field and neighbor magnetic anisotropy effect.
Part II. Infrared Spectroscopic Studies on the Influence of NaClO[subscript 4], LiClO[subscript 4], Mg(ClO[subscript 4])[subscript 2], Et[subscript 4]NClO[subscript 4], Bu[subscript 4]NI, Et[subscript 4]NBr, and Et[subscript 4]NCl on the OH Stretching Frequency of Water and Methanol in Acetonitrile.
The effects of NaClO[subscript 4], LiClO[subscript 4], Mg(ClO[subscript 4])[subscript 2], Et[subscript 4]NClO[subscript 4], Bu[subscript 4]NI, Et[subscript 4]NBr, and Et[subscript 4]NCl on the OH stretching frequency for H[subscript 2]0 and CH[subscript 3]OH and on the OD stretching frequency of D[subscript 2]0 and CD[subscript 3]OH in acetonitrile have been investigated. This work was undertaken to supplement the proton magnetic resonance studies reported in Part I. The various complex bands attributed to the various solvated complexes have been assigned and interpreted in terms of the symmetry and the structure of the solvated ion complex.
Part III. Infrared and Proton Magnetic Resonance Studies on the Polarization of Water and Methanol by Nat, LiI, and LiBr in an Aprotic Solvent.
In Parts I and II, a study of the polarization of water and methanol in an aprotic solvent by various diamagnetic salts was reported for the case where the polarization is dominated by one ion. In the more general case, the polarization of water or methanol by diamagnetic salts can be effected by both cation and anion. In this part, the results of some infrared and proton magnetic resonance studies on the polarization of water and methanol by NaI, LiI, and LiBr in an aprotic solvent are reported.
The infrared spectrum of the OH stretching and OD stretching vibration for the various ion complexes of water and methanol is characterized by the appearance of several bands. An attempt has been made towards the assignment and interpretation of the complex bands. The proton chemical shifts for the water resonance are also discussed and analyzed in terms of several possible ion water or methanol complexes. |
|---|