Suhina Tomislav, Amirjalayer Saeed, Mennucci Benedetta, Woutersen Sander, Hilbers Michiel, Bonn Daniel, Brouwer Albert M
van 't Hoff Institute for Molecular Sciences, University of Amsterdam , P.O. Box 94157, 1090 GD Amsterdam, The Netherlands.
van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam , P.O. Box 94485, 1090 GL Amsterdam, The Netherlands.
J Phys Chem Lett. 2016 Nov 3;7(21):4285-4290. doi: 10.1021/acs.jpclett.6b02277. Epub 2016 Oct 17.
The fluorescence intensity of molecular rotors containing the dicyanomethylenedihydrofuran (DCDHF) motif increases strongly with solvent viscosity. Single-bond and double-bond rotations have been proposed as pathways of nonradiative decay for this and related molecular rotors. We show here that both are involved in the case of DCDHF rotors: Fluorescence is quenched by rotation around the dicyanomethylene double bond in nonpolar solvents, but in a sufficiently polar environment rotation about a formally single bond leads to a dark internal charge-transfer state.
含有二氰基亚甲基二氢呋喃（DCDHF）基序的分子转子的荧光强度会随着溶剂粘度的增加而显著增强。单键和双键旋转已被提出作为此类及相关分子转子的非辐射衰变途径。我们在此表明，对于DCDHF转子，这两种途径都有涉及：在非极性溶剂中，围绕二氰基亚甲基双键的旋转会淬灭荧光，但在足够极性的环境中，围绕一个形式上的单键旋转会导致一种暗的内电荷转移态。
