醇与极性有机溶剂间氢键的多核NMR研究

醇是一类重要的有机溶剂,对其结构和性质的研究已有很长历史。由于OH的存在,醇分子间存在着较强的氢键缔合作用,使其结构变得复杂,因而较难对它得到一个很清楚的认识。用NMR方法研究氢键也有几十年历史。早在五十年代,Arnold,Becker等就用~1HNMR研究了EtOH在CCl_4中的行为,测量了化学位移随浓度的变化。Becker认为当醇浓度很稀时,体系中只存在单体-二聚体平衡,井结合IR数据求得了平衡常数及缔合物位移。有

Multi-Nuclear NMR Studies of Hydrogen Bonding Between Alcohols and Aprotic Solvents

Binary systems of alcohols and aprotic solvents have been studied systematically by NMR measurements. ~1H, ~(13)C, ~(15)N and ~(17)O chemical shifts and proton T_1 have been measured. The effects of solvents on ~1H and ~(13)C chemical shifts of alcohols were discussed. ~(13)C chemical shifts of α-carbon atom of alcohol were used to determine the ability of solvents to distort or disrupt the structure of alcohol, while their ~1H che-mical shifts were used to measure the strength of hydrogen bond between solvents and alcohols. The result was obtained showing that the stronger the solvent as a donor, the stronger its ability to disrupt the structure of alcohols.Chemical shifts of solvents hae also been measured. It was thought that their ...