Solid-state fluorescence of aromatic dicarboxamides. Dependence upon crystal packing
Journal
Journal of Physical Chemistry B
Journal Volume
101
Journal Issue
10
Pages
1775-1781
Date Issued
1997
Author(s)
Lewis, FD
Abstract
The fluorescence of six secondary arenedicarboxamides has been investigated in single crystals, powders, melts, and ethanol solution. Single crystals of four rodlike arenedicarboxamides which pack in one-dimensional tapes display dual emission attributed to excited-state monomers and dimers. These tapes have a constant 5-Å separation between the long axes of neighboring arenes but differ in the arene−arene dihedral angle. The frequency shift between monomer and dimer fluorescence and the intensity and vibronic structure of the dimer emission are dependent upon the ground-state geometry. Single crystals of two naphthalenedicarboxamides which pack in two-dimensional sheets and have no close contacts between neighboring arenes within the same sheet display only monomer emission. Melted and resolidified samples display broad structureless emission attributed to fluorescence from a mixture of excited monomers and dimers with different ground-state geometries.
SDGs
Type
journal article