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引言无机和分析化学中,常应用溶质和溶媒间的相互作用原理,将水溶液中的金属离子与适当的阴离子形成离子对或离子对复合盐而被提取入有机溶剂中,从而达到分离和提纯的目的。盐类能溶于有机层这一概念,在有机合成方法上加以应用,直到近年才得到注意,由此发展了相转移反应(Phase Transfer Reaction)。过去许多合成反应若在非均相条件下,特别是水和有机溶剂的二相中,反应很慢或不能进行。采用极性的质子溶剂,反应虽为均相,但由于阴离子可被溶剂化,活性降低,反应较慢,并可能发生如溶剂分解(Solvolysis)等副反应。近年来,采用一些极性非质子溶剂(aprotic solvent如二甲基甲酰胺DMF;二甲亚砜DMSO;六甲基膦酰胺HMPT等),对某些反应曾取得
Introduction Inorganic and analytical chemistry, the interaction between solute and the solvent is often applied to the principle, the metal ions in aqueous solution and the appropriate anion to form ion pairs or ions on the composite salt was extracted into organic solvents, so as to achieve separation and purification purpose. The concept that salts are soluble in organic layers has been applied in organic synthesis methods until it was noticed in recent years that phase transfer reactions have developed. In the past many synthetic reactions were slow or not working under heterogeneous conditions, especially in the two phases of water and organic solvents. The use of polar protic solvents, although the reaction is homogeneous, but the anion can be solvated, activity decreased, the reaction is slow, and may occur as solvent decomposition (Solvolysis) and other side effects. In recent years, some aprotic solvents such as dimethylformamide DMF; dimethyl sulfoxide DMSO; hexamethylphosphoramide HMPT, etc.) have been obtained for some reactions