Iridium a-Carboxyimine Complexes Hyperpolarized with para-Hydrogen Exist in Nuclear Singlet States before Conversion into Iridium Carbonates.
Iridium a-Carboxyimine Complexes Hyperpolarized with para-Hydrogen Exist in Nuclear Singlet States before Conversion into Iridium Carbonates.
复制标题
与对氢超极化的铱α-羧基胺配合物在转化为碳酸铱之前以核单线态存在。
DOI：
10.1002/cphc.201800829
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Tickner BJ
中科院分区：
文献类型：
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作者：
Tickner BJ
报道了[Ir（H）2（amine）（IMes）（η2-imine）]Cl配合物的形成和超极化，该配合物可以在超极化核单重态下产生。当丙酮酸盐、胺（苄胺或苯乙胺）和相应的亚胺缩合产物的平衡混合物与预先形成的[Ir（H）2（胺）3（IMes）]Cl反应时，形成这些络合物。这些铱α-羧基亚胺配合物以两种区域异构体存在，其区别在于胺的位置。当用仲氢检测时，胺反式氢化物的异构体的氢化物共振变得强烈超极化。初始氢化物单重态很容易转移到相应的13 C2标记的亚胺状态，并表现出高达11秒的磁态寿命。在9.4T下，它们的~（13）C信号被检测到高达420倍的信号增益。 在更长的时间尺度上，并且在不存在H2的情况下，进一步的反应导致形成含有[Ir（胺）（η2-CO 3）（IMes）（η2-亚胺）]的中性碳酸酯。配合物通过IR、MS、NMR和X射线衍射表征。
The formation and hyperpolarization of an [Ir(H)2(amine)(IMes)(η2‐imine)]Cl complex that can be created in a hyperpolarized nuclear singlet state is reported. These complexes are formed when an equilibrium mixture of pyruvate, amine (benzylamine or phenylethylamine), and the corresponding imine condensation product, react with preformed [Ir(H)2(amine)3(IMes)]Cl. These iridium α‐carboxyimine complexes exist as two regioisomers differentiated by the position of amine. When examined withpara‐hydrogen the hydride resonances of the isomer with amine trans to hydride become strongly hyperpolarized. The initial hydride singlet states readily transfer to the corresponding13C2state in the labelled imine and exhibit magnetic state lifetimes of up to 11 seconds. Their13C signals have been detected with up to 420 fold signal gains at 9.4 T. On a longer timescale, and in the absence of H2, further reaction leads to the formation of neutral carbonate containing [Ir(amine)(η2‐CO3)(IMes)(η2‐imine)]. Complexes are characterized by, IR, MS, NMR and X‐ray diffraction.