当前位置: X-MOL 学术J. Phys. Chem. Lett. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Intermolecular Hydrogen Bonding Controlled Intersystem Crossing Rates of Benzophenone
The Journal of Physical Chemistry Letters ( IF 5.7 ) Pub Date : 2018-03-14 00:00:00 , DOI: 10.1021/acs.jpclett.8b00345
Ravi Kumar Venkatraman 1, 2 , Surajit Kayal 1 , Arvind Barak 1 , Andrew J. Orr-Ewing 2 , Siva Umapathy 1, 3
Affiliation  

Solvation plays a critical role in various physicochemical and biological processes. Here, the rate of intersystem crossing (ISC) of benzophenone from its S1(nπ*) state to its triplet manifold of states is shown to be modified by hydrogen-bonding interactions with protic solvent molecules. We selectively photoexcite benzophenone with its carbonyl group either solvent coordinated or uncoordinated by tuning the excitation wavelength to the band center (λ = 340 nm) or the long-wavelength edge (λ = 380 nm) of its π* ← n absorption band. A combination of ultrafast absorption and Raman spectroscopy shows that the hydrogen-bonding interaction increases the time constant for ISC from <200 fs to 1.7 ± 0.2 ps for benzophenone in CH3OH. The spectroscopic evidence suggests that the preferred pathway for ISC is from the S1(nπ*) to the T2(ππ*) state, with the rate of internal conversion from T2(ππ*) to T1(nπ*) controlled by solvent quenching of excess vibrational energy.

中文翻译:

分子间氢键控制的苯甲酮的系统间交叉速率。

溶剂化在各种物理化学和生物过程中起着至关重要的作用。在此,二苯甲酮从其S 1(nπ*)状态到其三重态状态的系统间穿越(ISC)速率显示出通过与质子溶剂分子的氢键相互作用而改变。我们通过将激发波长调节到其π*←n吸收带的能带中心(λ= 340 nm)或长波长边缘(λ= 380 nm),来选择性激发具有羰基的二苯甲酮,该二苯甲酮的溶剂是配位的或未配位的。超快吸收和拉曼光谱的结合显示,氢键相互作用将ISC的时间常数从<200 fs增加到CH 3中的二苯甲酮的1.7±0.2 ps。哦。光谱证据表明,ISC的首选途径是从S 1(nπ*)到T 2(ππ*)状态,从T 2(ππ*)到T 1(nπ*)的内部转化率受到控制通过溶剂淬灭多余的振动能量。
更新日期:2018-03-14
down
wechat
bug