1 H NMR研究溶质浓度对三碳多元醇水溶液氢键作用以及玻璃化的影响
1 H NMR研究溶质浓度对三碳多元醇水溶液氢键作用以及玻璃化的影响
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DOI：
10.3866/pku.whxb20111103
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发表时间：
2011-08
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研究了溶质浓度对三碳多元醇水溶液氢键相互作用的影响，用质子核磁共振（~1H NMR）方法测定了水与1-丙醇（NPA）、2-丙醇（IPA）、1，2-丙二醇（PG）、1，3-丙二醇（PD）、用外标法测定了PG和甘油在室温和常压下的烷基质子化学位移，发现PG与CH_3CH（OH）-基团的烷基质子化学位移呈双相行为，与其他分子不同，水分子形成相对较强的O-H_2O和羟基质子的化学位移随醇羟基数的增加而减小，在相同的摩尔分数下，H_2O和羟基质子的化学位移随醇羟基数的增加而减小。相同醇羟基数的H_2O和羟基质子的质子化学位移因位置不同而不同，碱性增加的顺序与冰均质成核抑制增加的顺序一致，这解释了为什么甘油和PG更适合作为五种多元醇中的冷冻保护剂（CPA）。
We investigated the effects of solute concentration on the hydrogen bonding interactions of three-carbon polyalcohol aqueous solutions.In order to inspect the capacity of the solutions to form glass, proton nuclear magnetic resonance(~1H NMR) chemical shifts were determined in binary mixtures of water and 1-propanol(NPA),2-propanol(IPA),1,2-propanediol(PG),1,3-propanediol(PD),and glycerol at room temperature and at atmospheric pressure using the external reference method.We found that the alkyl proton chemical shifts of PG with the CH_3CH(OH)—group showed biphasic behavior,which was different from other molecules.Water molecules formed relatively strong O—H…O hydrogen bonds with the alcohol hydroxyls.The proton chemical shifts of H_2O and the hydroxyl protons decrease with an increase in the number of alcohol hydroxyls at the same mole fraction.Moreover,the proton chemical shifts of H_2O and hydroxyl protons with the same number of alcohol hydroxyls are different because of their different locations.The order of increased basicity agrees with the order of increased ice homogeneous nucleation suppression,that is,glycerolPGPDIPANPA.This explains why glycerol and PG are more suitable as cryoprotective agents(CPAs) among the five polyalcohols.
DOI：
10.1533/9781845697471
发表时间：
2010-07
期刊：
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影响因子：
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作者：
T. Hua;Baolin Liu;Haimei Zhang
通讯作者：
T. Hua;Baolin Liu;Haimei Zhang