کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5375906 1504311 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Photophysics of inter- and intra-molecularly hydrogen-bonded systems: Computational studies on the pyrrole-pyridine complex and 2(2′-pyridyl)pyrrole
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Photophysics of inter- and intra-molecularly hydrogen-bonded systems: Computational studies on the pyrrole-pyridine complex and 2(2′-pyridyl)pyrrole
چکیده انگلیسی
The role of electron and proton transfer processes in the photophysics of hydrogen-bonded molecular systems has been investigated with ab initio electronic-structure calculations. We discuss generic mechanisms of the photophysics of a hydrogen-bonded aromatic pair (pyrrole-pyridine), as well as an intra-molecularly hydrogen-bonded π system composed of the same molecular sub-units (2(2′-pyridyl)pyrrole). The reaction mechanisms are discussed in terms of excited-state minimum-energy paths, conical intersections and the properties of frontier orbitals. A common feature of the photochemistry of these systems is the electron-driven proton transfer (EDPT) mechanism. In the hydrogen-bonded complex, a highly polar charge transfer state of 1ππ∗ character drives the proton transfer, which leads to a conical intersection of the S1 and S0 surfaces and thus ultrafast internal conversion. In 2(2′-pyridyl)pyrrole, out-of-plane torsion is additionally needed for barrierless access to the S1-S0 conical intersection. It is pointed out that the EDPT process plays an essential role in the fluorescence quenching in hydrogen-bonded aromatic complexes, the function of organic photostabilizers, and the photostability of biological molecules.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Physics - Volume 347, Issues 1–3, 23 May 2008, Pages 413-421
نویسندگان
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