论文部分内容阅读
本文测定了 NaClO_4在水-丙酮,水-乙腈,水-乙醇以及 NaBPh_4在甲醇-DMF,甲醇-苯,甲醇-二氧六圜混合溶剂体系中~(23)Na~+的化学位移随溶剂组成的变化规律。利用等溶剂化点比较了各溶剂对 Na~+的溶剂化能力:H_2O>(CH_3)_2CO≥CH_3CN≥C_2H_5OH;DMF>CH_3OH。对于甲醇-DMF 和水-丙酮体系,估算出 DMF 对甲醇,丙酮对水的 Na~+优先溶剂化自由能分别为-2.7kJmol~(-1)和+4.6kJmol~(-1)。在甲醇-苯混合溶剂体系中,~(23)Na~+的化学位移独立于苯的含量。它支持了甲醇-惰性溶剂混合体系的单一溶剂化模型。而在甲醇-二氧六圜体系中~(23)Na~+的化学位移随混合溶剂组成而发生变化。~(23)Na~+磁共振的峰宽随二氧六圜的加入急剧增加,这表明二氧六圜分子可能进入了在甲醇中的 Na~+原溶剂化层,导致了 Na~+化学环境不对称。
In this paper, the chemical shifts of NaClO_4 in water - acetone, water - acetonitrile, water - ethanol and NaBPh_4 in a mixed solvent system of methanol - DMF, methanol - benzene and methanol - The law of change. The solvating ability of each solvent to Na ~ + was compared by iso-solvating point: H_2O> (CH_3) _2CO≥CH_3CN≥C_2H_5OH; DMF> CH_3OH. For methanol-DMF and water-acetone systems, the preferential solvation energies of DMF + methanol and acetone on water were estimated to be -2.7kJmol -1 and + 4.6kJmol -1, respectively. The chemical shift of ~ (23) Na ~ + in methanol - benzene mixed solvent system is independent of the benzene content. It supports a single solvation model of a methanol-inert solvent blend. However, the chemical shift of ~ (23) Na ~ + in methanol-dioxane system changed with the composition of mixed solvent. The peak width of ~ (23) Na ~ + magnetic resonance sharply increased with the addition of dioxane, indicating that dioxane molecules may have entered the Na ~ + protolytic layer in methanol, leading to Na ~ + chemistry The environment is not symmetrical.