Rebane Aleksander, Wicks Geoffrey, Drobizhev Mikhail, Cooper Thomas, Trummal Aleksander, Uudsemaa Merle
Deptartment of Physics, Montana State University, 264 EPS, Bozeman, MT 59717 (USA).
National Institute of Chemical Physics and Biophysics, Tallinn (Estonia).
Angew Chem Int Ed Engl. 2015 Jun 22;54(26):7582-6. doi: 10.1002/anie.201502157. Epub 2015 May 8.
We present a new approach for determining the strength of the dipolar solute-induced reaction field, along with the ground- and excited-state electrostatic dipole moments and polarizability of a solvated chromophore, using exclusively one-photon and two-photon absorption measurements. We verify the approach on two benchmark chromophores N,N-dimethyl-6-propionyl-2-naphthylamine (prodan) and coumarin 153 (C153) in a series of toluene/dimethyl sulfoxide (DMSO) mixtures and find that the experimental values show good quantitative agreement with literature and our quantum-chemical calculations. Our results indicate that the reaction field varies in a surprisingly broad range, 0-10(7) V cm(-1) , and that at close proximity, on the order of the chromophore radius, the effective dielectric constant of the solute-solvent system displays a unique functional dependence on the bulk dielectric constant, offering new insight into the close-range molecular interaction.
我们提出了一种全新的方法，仅通过单光子和双光子吸收测量，来确定偶极溶质诱导反应场的强度，以及溶剂化发色团的基态和激发态静电偶极矩与极化率。我们在一系列甲苯/二甲基亚砜（DMSO）混合物中，对两种基准发色团N,N-二甲基-6-丙酰基-2-萘胺（prodan）和香豆素 153（C153）验证了该方法，发现实验值与文献及我们的量子化学计算结果在定量上吻合良好。我们的结果表明，反应场在0至10⁷ V cm⁻¹这一惊人的宽范围内变化，并且在接近发色团半径的尺度上，溶质 - 溶剂系统的有效介电常数对本体介电常数呈现出独特的函数依赖性，这为近距离分子相互作用提供了新的见解。
