| Autor: |
Iwamoto, Etsuro, Yamasaki, Shoji, Kumamaru, Takahiro |
| Zdroj: |
Bulletin of the Chemical Society of Japan; June 1989, Vol. 62 Issue: 6 p1692-1697, 6p |
| Abstrakt: |
The basicity of water in methanol (MeOH) and MeOH–1,2-dichloroethane (DCE) mixtures was examined by using spectral data of the title square planar chelate cation ([Ni(tmc)]2+). Although MeOH molecules are hardly coordinated to the chelate, the water molecules hydrogen-bonded with MeOH are easily coordinated to the cation, depending on the degree of hydrogen-bonded networks of MeOH. A fitting method showed that in the MeOH-rich mixtures the dimerization of water occured and only the terminal monomeric water molecule in the MeOH oligomer could be coordinated. The equilibrium constant KNiW1=[Ni(tmc)(H2O)2+]/[Ni(tmc)2+][H2O] was 3.2 in the 0.1 MeOH mole fraction mixture, 3.0 in 0.3, 3.2 in 0.5, 6.2 in 0.7, 9.5 in 0.9, 10.0 in 1.0. Linear relationships of 1H chemical shift of the OH group for MeOH in various solvents with the KNiW1values and Gutmann’s donor number (DN) were found and DN values were estimated for the DCE–MeOH mixtures. The enhancement of basicity of the water molecules was discussed from the viewpoints of the charge transfer effect through hydrogen bonding and the development of hydrogen-bonded networks. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
