Reaction Monitoring Using SABRE-Hyperpolarized Benchtop (1 T) NMR Spectroscopy
Reaction Monitoring Using SABRE-Hyperpolarized Benchtop (1 T) NMR Spectroscopy
复制标题
使用 SABRE-超极化台式 (1 T) NMR 波谱监测反应
DOI：
10.1021/acs.analchem.9b00729
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发表时间：
2019
影响因子：
7.4
通讯作者：
S. Duckett
中科院分区：
文献类型：
--
作者：
O. Semenova;P. M. Richardson;Andrew J. Parrott;A. Nordon;M. Halse;S. Duckett
[IrCl（COD）（IMes）]的转化率（COD =顺式，顺式-1，5-环辛二烯，IMes = 1，3-双（2，4，6-三甲基-苯基）咪唑-2-亚基）在过量的仲氢（p-H2）和底物存在下反应（4-氨基吡啶（4-AP）或4-甲基吡啶（4-MP））转化为[Ir（H）2（IMes）]使用台式（1 T）光谱仪结合基于p-H2的超极化技术可逆交换信号放大（SABRE），通过1H NMR光谱法监测[底物] 3]Cl。一系列单次1H NMR测量用于监测在超极化响应的寿命期间溶液中发生的化学变化。非超极化高场1H NMR控制测量也进行了确认，所观察到的时间依赖性的变化直接相关的基础化学演变。[Ir（H）2（IMes）（substrate）3]Cl的形成进一步与氢同位素交换（HIE）反应有关，这导致氘掺入4-AP的邻位，其中氘的来源是溶剂甲醇-d4。在高场（9.4 T）和低场（1 T）下均获得了相当的反应监测结果。值得注意的是，台式（1 T）NMR的低灵敏度使得能够使用质子溶剂，当在此使用质子溶剂时，其允许分离催化剂形成和底物氘化的影响。总的来说，这些方法说明了低成本低场NMR测量如何通过超极化和弛豫数据的组合提供对复杂催化过程的独特见解。
The conversion of [IrCl(COD)(IMes)] (COD = cis,cis-1,5-cyclooctadiene, IMes = 1,3-bis(2,4,6-trimethyl-phenyl)imidazole-2-ylidene) in the presence of an excess of para-hydrogen (p-H2) and a substrate (4-aminopyridine (4-AP) or 4-methylpyridine (4-MP)) into [Ir(H)2(IMes)(substrate)3]Cl is monitored by 1H NMR spectroscopy using a benchtop (1 T) spectrometer in conjunction with the p-H2-based hyperpolarization technique signal amplification by reversible exchange (SABRE). A series of single-shot 1H NMR measurements are used to monitor the chemical changes that take place in solution through the lifetime of the hyperpolarized response. Non-hyperpolarized high-field 1H NMR control measurements were also undertaken to confirm that the observed time-dependent changes relate directly to the underlying chemical evolution. The formation of [Ir(H)2(IMes)(substrate)3]Cl is further linked to the hydrogen isotope exchange (HIE) reaction, which leads to the incorporation of deuterium into the ortho positions of 4-AP, where the source of deuterium is the solvent, methanol-d4. Comparable reaction monitoring results are achieved at both high-field (9.4 T) and low-field (1 T). It is notable that the low sensitivity of the benchtop (1 T) NMR enables the use of protio solvents, which when used here allows the effects of catalyst formation and substrate deuteration to be separated. Collectively, these methods illustrate how low-cost low-field NMR measurements provide unique insight into a complex catalytic process through a combination of hyperpolarization and relaxation data.
影响因子：
15
作者：
Colell JFP;Emondts M;Logan AWJ;Shen K;Bae J;Shchepin RV;Ortiz GX Jr;Spannring P;Wang Q;Malcolmson SJ;Chekmenev EY;Feiters MC;Rutjes FPJT;Blümich B;Theis T;Warren WS
通讯作者：
Warren WS
超极化甲硝唑在微特斯拉场中可逆交换信号放大中的自旋晶格弛豫。
DOI：
10.1021/acs.jpcc.8b00283
发表时间：
2018
期刊：
The journal of physical chemistry. C, Nanomaterials and interfaces
影响因子：
--
作者：
Shchepin,RomanV;Jaigirdar,Lamya;Chekmenev,EduardY
通讯作者：
Chekmenev,EduardY