Infrared spectroscopy of the n-propyl and i-propyl radicals in solid para-hydrogen
Infrared spectroscopy of the n-propyl and i-propyl radicals in solid para-hydrogen
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固体仲氢中正丙基和异丙基自由基的红外光谱
DOI：
10.1016/j.jms.2019.07.001
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发表时间：
2019
影响因子：
1.4
通讯作者：
G. Douberly
中科院分区：
文献类型：
--
作者：
Gregory Pullen;P. Franke;K. Haupa;Yuan‐Pern Lee;G. Douberly
我们报道了固相对氢（p-H2）中分离的邻丙基和二丙基自由基的红外光谱。通过248 nm辐照对h2p与1-碘丙烷（形成n-丙基）或2-碘丙烷（形成i-丙基）共沉积形成的基质产生丙基自由基。利用次生光解作用对同一物种产生的光谱带进行分组。除了以前在氩矩阵或氦液滴光谱中观察到的那些外，我们还分配了大约20个以前未报道的波段。与VPT2+K的非谐波频率计算进行了比较，对丙基自由基的特征分配进行了比较。在单独的测量中，丙基自由基是通过丙烯和羟基基质中产生的氢原子之间的反应产生的。由于势垒在700 ~ 1500 cm−1之间，因此在固体- h2at 3.3 K中进行的H + 丙烯反应必然受到隧道控制。i-丙基自由基产生的丰度是-丙基自由基的5-20倍，这表明H原子加到末端碳上的速度比加到中心碳上的速度快。将wentzl - kramer - brillouin近似应用于一维实验室初始势来估计正丙基和二丙基形成的隧穿时间常数。该模型预测末端碳（形成i-丙基）的加成速率要快17倍，与实验分支比定性一致。
We report infrared spectra of then- andi-propyl radicals isolated in solidpara-hydrogen (p-H2). Propyl radicals were producedvia248 nm irradiation of matrices formed by co-deposition ofp-H2and either 1-iodopropane (formingn-propyl) or 2-iodopropane (formingi-propyl). Secondary photolysis was used to group spectral bands arising from the same species. In addition to those observed previously in either argon matrix or helium droplet spectra, we assign approximately 20 previously unreported bands. The assignment of features to propyl radicals is madeviacomparisons to VPT2+K anharmonic frequency computations. In separate measurements, propyl radicals were generatedviathe reaction between propene and hydrogen atoms produced within thep-H2matrix. Because the barriers are between 700 and 1500 cm−1, the H + propene reaction is necessarily under tunneling control when carried out in solidp-H2at 3.3 K.i-Propyl radicals were produced in ∼5–20 times greater abundance thann-propyl radicals, indicating that H atom addition to the terminal carbon is faster than addition to the central carbon. The Wentzl-Kramers-Brillouin approximation is applied to one-dimensionalab initiopotentials to estimate the tunneling time constants for formation ofn- andi-propyl. This model predicts the rate of addition to the terminal carbon (formingi-propyl) to be 17 times faster, in qualitative agreement with the experimental branching ratio.
固体仲氢和氦液滴中丙烯的红外光谱：基质位移在非简谐振动分析中的作用
影响因子：
1.4
作者：
Pullen, Gregory T.;Franke, Peter R.;Lee, Yuan-Pern;Douberly, Gary E.
通讯作者：
Douberly, Gary E.
影响因子：
15
作者：
P. Schreiner;J. Wagner;H. Reisenauer;D. Gerbig;D. Ley;János Sarka;A. Császár;Alexander Vaughn;W. D. Allen
通讯作者：
P. Schreiner;J. Wagner;H. Reisenauer;D. Gerbig;D. Ley;János Sarka;A. Császár;Alexander Vaughn;W. D. Allen