Ultrafast photodissociation dynamics of the S1 and S2 states of acetone
Ultrafast photodissociation dynamics of the S1 and S2 states of acetone
复制标题
丙酮 S1 和 S2 态的超快光解动力学
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
A. Baronavski
中科院分区：
文献类型：
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作者：
J. Owrutsky;A. Baronavski
用飞秒质量分辨光电离谱研究了丙酮(h6和d6)的两个最低激发电子态(S_1价态和S_2，3S里德堡态)的光解离动力学。用近紫外泵浦光(∼2 6 5 nm)和深紫外光(2 0 5 Nm)或可见光(4 10 Nm)探针研究了S1态的动力学。一次解离时间受仪器限制，寿命上限为200fs。乙酰离子信号呈现亚皮秒衰减和持续信号。这种快速衰变与Kim等人的结果一致。作者声明：[J.Chem.太棒了。103,477(1995)]将双光子激发到接近4s态。持续的信号是由于探针诱导的乙酰基的电离，这些乙酰基相对于二次解离是稳定的。用194泵浦和259 nm探针法测得丙酮-d6的S2激发态寿命为13.5±1.0 ps。这几乎是我们之前在丙酮中测得的这种状态的三倍长-h6，4.7±0.2 ps。塞科..。
The photodissociation dynamics for the two lowest excited electronic states (S1 valence state and the S2, 3s Rydberg state) of acetone (h6 and d6) have been studied using femtosecond mass-resolved photoionization spectroscopy. The S1 state dynamics was investigated by near ultraviolet (UV) pump (∼265 nm) and deep UV (205 nm) or visible (410 nm) probe. The primary dissociation time is instrument-limited, providing a 200 fs upper limit to the lifetime. The acetyl ion signal exhibits a subpicosecond decay and a persistent signal. The fast decay is consistent with results from Kim et al. [J. Chem. Phys. 103, 477 (1995)] for two-photon excitation to near the 4s state. The persistent signal is due to probe-induced ionization of acetyl radicals that are stable with respect to secondary dissociation. The S2 excited state lifetime measured for acetone-d6 using 194 pump and 259 nm probe is 13.5±1.0 ps. This is almost three times longer than we previously determined for this state in acetone-h6, 4.7±0.2 ps. The seco...