1H NMR analysis of cellulose dissolved in non-deuterated ionic liquids
1H NMR analysis of cellulose dissolved in non-deuterated ionic liquids
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DOI：
10.1007/s10570-014-0271-x
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发表时间：
2014-08-01
期刊：
影响因子：
5.7
通讯作者：
Ohno, Hiroyuki
中科院分区：
文献类型：
--
作者：
Kuroda, Kosuke;Kunimura, Haruhito;Ohno, Hiroyuki
对非氘代极性离子液体 (IL) 中的纤维素进行 H-1 NMR 光谱分析，以分析纤维素和 IL 之间的特异性相互作用。我们应用极性 IL，1,3-二甲基咪唑鎓甲基甲基膦酸酯作为 1 H NMR 光谱的纤维素溶剂。为了防止氢氘交换导致羟基 (C-OH) 信号消失，使用非氘化离子液体，借助氘核磁共振技术和溶剂抑制技术成功检测到 C-OH 和骨架质子信号。已证实 C-OH 与 IL 的相互作用比主链质子更强烈。此外，独立观察到2-位、3-位和6-位的C-OH的信号。 6位C-OH与IL之间的强相互作用被证实是纤维素溶解的关键步骤。
H-1 NMR spectroscopy of cellulose in a non-deuterated polar ionic liquid (IL) was carried out to analyze specific interaction between cellulose and ILs. We applied a polar IL, 1,3-dimethylimidazolium methyl methylphosphonate, as a cellulose solvent for 1 H NMR spectroscopy. To prevent vanishing of the signals of hydroxyl groups (C-OHs) by hydrogendeuterium exchange, a non-deuterated IL was utilized, and both signals for C-OHs and backbone protons were successfully detected with the aid of the nodeuterium NMR technique and a solvent suppression technique. It was confirmed that C-OHs interacted with ILs more strongly, rather than backbone protons. Furthermore, the signals of the C-OHs at 2-, 3-, and 6-position were independently observed. A strong interaction between C-OH at the 6-position and ILs was confirmed to be a key step for dissolution of cellulose.