Intramolecular π-Stacking Interaction in a Rigid Molecular Hinge Substituted with 1-(Pyrenylethynyl) Units

摘要

Synthesis of a tetrakis(1-pyrenylethynyl)-substituted rigid hinge-like molecule (1) is described. The intramolecular π-stacking interaction of the pyrene units is studied by ~1H NMR and fluorescence spectroscopy. Due to intramolecular π-stacking interactions, chemical shifts of the pyrene protons in 1 are highly shielded in the NMR spectrum. Fluorescence from the static excimer state is observed due to π-stacking interactions among the pyrene units in the ground state of 1. Based on the spectroscopic evidence, conformations and dynamics of 1, arising from the hindered rotation of the major axis, are proposed.