A fluoresceinophane: 1<sup>9</sup>,4,16-trioxa-1(2,10)-anthracena-2(1,2)-benzenacyclohexadecaphane-1<sup>7</sup>,3(1<sup>9</sup><i>H</i>)-dione
作者:Stéphane Dufresne、Sergio Andrés Pérez Guarìn、W. G. Skene
DOI:10.1107/s0108270107008566
日期:2007.6.15
A novel macrocycle containing fluorescein, the highly fluorescent title compound, C31H32O5, has a xanthene core and a benzyl unit that are planar. The latter is rotated by 72.99 (3)degrees from the xanthene mean plane. The C-11 alkyl tether and the xanthene group adopt a cage-like structure and the xanthene adopts a quinoid-type configuration. The compound crystallizes as a racemic mixture with one molecule of each isomer per unit cell. Even though the planes described by the xanthene and the benzene rings of different molecules are separated by 3.341 (4) and 3.73 (1) angstrom, respectively, there is insufficient overlap between the aryl units to promote pi-stacking.
Spectroscopic studies of a fluorescent fluoresceinophane formed via a practical synthetic route
作者:Sergio Andrés Peréz Guarìn、Derek Tsang、W. G. Skene
DOI:10.1039/b611060f
日期:——
A practical macrocycle synthesis incorporating a highly fluorescent fluorescein was developed. Photophysical, crystallographic and dynamic-NMR studies showed the alkyl tether forces a constrained conformation of the fluoresceinophane, which enhances the fluorescence quantum yields by reducing the excited-state deactivation pathways. Enhanced temperature-dependent fluorescence relative to its linear analogue was also found as a result of the constrained macrocycle conformation, while a manifold shift from the singlet to the triplet state still occurred in different polar solvents.