Mapping the photochemistry of cyclopentadiene: from theory to ultrafast X-ray scattering
Mapping the photochemistry of cyclopentadiene: from theory to ultrafast X-ray scattering
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DOI：
10.1039/d2fd00176d
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发表时间：
2023-02-10
影响因子：
3.4
通讯作者：
Kirrander，Adam
中科院分区：
文献类型：
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作者：
Bertram，Lauren;Weber，Peter M.;Kirrander，Adam
采用XMS（3）-CASPT 2（4，4）/cc-pVDZ电子结构理论，采用表面跳跃半经典轨道方法，模拟了环戊二烯（CP）在5.10 eV激发下的光诱导环转化反应.此外，PBE 0/def 2-SV（P）用于轨道的基态传播。动力学传播10 ps，映射非绝热短时动力学（<300 fs）和电子基态上越来越多的统计动力学。短时间动力学产生热CP和双环[2.1.0]戊烯（BP）的混合物，其中两种产物经由相同锥形相交接缝的不同区域到达。在基态上，我们观察到从BP到CP的缓慢转化，这是由RRKM理论建模的，过渡态使用PBE 0/def 2-TZVP确定。CP产物还与基态氢位移和一些H原子解离有关。最后，详细的实验映射使用新的超快X射线散射实验的前景进行了讨论，并预测这些实验的观测值。特别是，我们评估的可能性检索电子状态和他们的人口旁边的结构动态。
The photoinduced ring-conversion reaction when cyclopentadiene (CP) is excited at 5.10 eV is simulated using surface-hopping semiclassical trajectories with XMS(3)-CASPT2(4,4)/cc-pVDZ electronic structure theory. In addition, PBE0/def2-SV(P) is employed for ground state propagation of the trajectories. The dynamics is propagated for 10 ps, mapping both the nonadiabatic short-time dynamics (<300 fs) and the increasingly statistical dynamics on the electronic ground state. The short-time dynamics yields a mixture of hot CP and bicyclo[2.1.0]pentene (BP), with the two products reached via different regions of the same conical intersection seam. On the ground state, we observe slow conversion from BP to CP which is modelled by RRKM theory with a transition state determined using PBE0/def2-TZVP. The CP products are furthermore associated with ground state hydrogen shifts and some H-atom dissociation. Finally, the prospects for detailed experimental mapping using novel ultrafast X-ray scattering experiments are discussed and observables for such experiments are predicted. In particular, we assess the possibility of retrieving electronic states and their populations alongside the structural dynamics.