Heterogeneous Parahydrogen Pairwise Addition to Cyclopropane.
Heterogeneous Parahydrogen Pairwise Addition to Cyclopropane.
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DOI：
10.1002/cphc.201800690
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发表时间：
2018-10-19
期刊：
影响因子：
--
通讯作者：
Chekmenev EY
中科院分区：
文献类型：
--
作者：
Salnikov OG;Kovtunov KV;Nikolaou P;Kovtunova LM;Bukhtiyarov VI;Koptyug IV;Chekmenev EY
超极化气体彻底改变了肺功能成像。超极化丙烷是一种很有前途的新型肺部MRI造影剂。与超极化惰性气体不同，质子-超极化丙烷气体可以使用具有质子成像能力的传统MRI扫描仪进行成像。此外，它是无毒无味的麻醉剂。此外，丙烷的超极化可以通过向丙烯中成对加成对氢来实现。在这里，我们证明了丙烷超极化的可行性环丙烷加氢与对氢。在82%的对氢富集和非均相Rh/TiO2加氢催化剂下，丙烷的1H极化率可达2.4%。在相同条件下，这种极化水平是丙烯前体的几倍，尽管对氢直接成对加成到环丙烷也可能导致丙烷的形成具有核磁共振不可见的超极化，这是由于两个CH3基团中新生的对氢质子的磁等效。核磁共振可见的超极化丙烷只能通过裂解反应物分子中至少一个碳氢键的反应途径形成。尽管环丙烷底物的化学转化率相对较低，但超极化丙烷的核磁共振信号增强足以用于~5.5 mL幻影的二维梯度回波MRI，其空间分辨率为1×1 mm2，成像矩阵为64×64。在Rh/TiO2催化剂上，对氢与环丙烷的非均相加氢反应被证明是一种很有前途的生产丙烷气体的方法，具有高水平的质子极化，适合于磁共振成像应用。
Hyperpolarized gases revolutionize functional pulmonary imaging. Hyperpolarized propane is a promising emerging contrast agent for pulmonary MRI. Unlike hyperpolarized noble gases, proton-hyperpolarized propane gas can be imaged using conventional MRI scanners with proton imaging capability. Moreover, it is non-toxic odorless anesthetic. Furthermore, propane hyperpolarization can be accomplished by pairwise addition of parahydrogen to propylene. Here, we demonstrate the feasibility of propane hyperpolarization via hydrogenation of cyclopropane with parahydrogen. 1H propane polarization up to 2.4% is demonstrated here using 82% parahydrogen enrichment and heterogeneous Rh/TiO2 hydrogenation catalyst. This level of polarization is several times greater than that of propylene precursor under the same conditions despite the fact that direct pairwise addition of parahydrogen to cyclopropane may also lead to formation of propane with NMR-invisible hyperpolarization due to magnetic equivalence of nascent parahydrogen protons in two CH3 groups. NMR-visible hyperpolarized propane demonstrated here can be formed only via a reaction pathway involving cleavage of at least one C–H bond in the reactant molecule. The resulting NMR signal enhancement of hyperpolarized propane was sufficient for 2D gradient echo MRI of ~5.5 mL phantom with 1×1 mm2 spatial resolution and 64×64 imaging matrix despite relatively low chemical conversion of cyclopropane substrate. Layout 1: COMMUNICATION Heterogeneous hydrogenation of cyclopropane with parahydrogen over Rh/TiO2 catalyst was shown to be a promising approach for production of propane gas with high level of proton polarization suitable for magnetic resonance imaging applications.
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影响因子：
4.3
作者：
Corma, Avelino;Salnikov, Oleg G.;Koptyug, Igor V.
通讯作者：
Koptyug, Igor V.
影响因子：
19.7
作者：
Driehuys, Bastiaan;Martinez-Jimenez, Santiago;McAdams, H. Page
通讯作者：
McAdams, H. Page
DOI：
10.1002/asia.201800551
发表时间：
2018-05-23
期刊：
Chemistry, an Asian journal
影响因子：
--
作者：
Kovtunov KV;Pokochueva EV;Salnikov OG;Cousin SF;Kurzbach D;Vuichoud B;Jannin S;Chekmenev EY;Goodson BM;Barskiy DA;Koptyug IV
通讯作者：
Koptyug IV
影响因子：
64.8
作者：
ALBERT, MS;CATES, GD;WISHNIA, A
通讯作者：
WISHNIA, A
影响因子：
3.7
作者：
Barskiy, Danila A.;Kovtunov, Kirill V.;Chekmenev, Eduard Y.
通讯作者：
Chekmenev, Eduard Y.