The effect of CO rotation from shaped pulse polarization on reactions that form C 2
The effect of CO rotation from shaped pulse polarization on reactions that form C 2
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成形脉冲极化产生的 CO 旋转对形成 C 2 的反应的影响
DOI：
10.1039/c8cp06917d
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发表时间：
2019
影响因子：
3.3
通讯作者：
Mullin, Amy S.
中科院分区：
文献类型：
--
作者：
Ogden, Hannah M.;Michael, Tara J.;Murray, Matthew J.;Liu, Qingnan;Toro, Carlos;Mullin, Amy S.
本文报道了CO转动能对生成电子激发态C2的双分子反应的影响。该反应是由CO多光子吸收的800 nm的光在强光场使用两种不同的偏振配置的基础上成形啁啾脉冲。通过对C2（d3·g）的Swan带发射的观察，表明C2（d3·g）是反应产物。光学偏振的形式是光学离心机或动态偏振光栅。在每种情况下，强场使CO分子排列并诱导多光子吸收。依赖于功率的测量表明至少有七个光子被CO吸收; CO（a3）是基于动力学建模的可能的反应物候选物。相对反应效率通过测量天鹅带发射强度来确定。对于100 Torr的CO压力和I = 2.0 × 1013 W cm-2的光强度，动态偏振光栅的相对C2（d3 g）产率是光学离心机的两倍。对于两种光学偏振，CO旋转能量的范围是使用高分辨率瞬态IR吸收来确定的，这些CO状态的J = 62-73，Erot高达10 400 cm−1。 光学离心激发产生至少2.5倍以上的每个量子态的旋转激发的CO分子比动态偏振光栅。结果表明，大量的CO转动能的作用是降低C2产物的产率。
The effect of CO rotational energy on bimolecular reactions to form electronically excited C2 is reported here. The reactions are initiated by CO multiphoton absorption of 800 nm light in strong optical fields using two different polarization configurations based on shaped chirped pulses. The observation of Swan band emission indicates that C2(d3Πg) is a reaction product. The optical polarization is in the form of either an optical centrifuge or a dynamic polarization grating. In each case, the strong field aligns CO molecules and induces multiphoton absorption. Power-dependent measurements indicate at least seven photons are absorbed by CO; CO(a3Π) is a likely reactant candidate based on kinetic modeling. Relative reaction efficiencies are determined by measuring Swan band emission intensities. For a CO pressure of 100 Torr and an optical intensity of I = 2.0 × 1013 W cm−2, the relative C2(d3Πg) yield with the dynamic polarization grating is twice that with the optical centrifuge. The extent of CO rotational energy was determined for both optical polarizations using high-resolution transient IR absorption for a number of CO states with J = 62–73 and Erot up to 10 400 cm−1. Optical centrifuge excitation generates at least 2.5 times more rotationally excited CO molecules per quantum state than the dynamic polarization grating. The results indicate that the effect of large amounts of CO rotational energy is to reduce the yield of the C2 products.