Publication details
Fluorescence anisotropy of bicyclo[1.1.1]pentane/oligophenyl based rods included in TPP
| Authors | |
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| Year of publication | 2012 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Motion of rod-like molecules included into the channels of hexagonal (tris-o-phenylenedioxy)cyclotriphosphazine (TPP) have been examined in the past by NMR techniques. We now report an examination of this motion by fluorescence anisotropy measurements with time resolution in the fs range as a function of temperature, using suspensions of nanocrystals of TPP loaded with 0.02 - 2% of the guests. The included molecular rods, specially synthesized for the purpose, contained a fluorophore (such as quaterphenyl or pyridazine) held between two bulky groups (such as 1,3-disubstituted bicyclo[1.1.1]pentanes), which were found to fix the orientation of the long axis along the TPP channel direction. At high guest loadings, concentration depolarization interfered with the interpretation of the measurements, but in highly diluted samples this interference disappeared and the long molecular axis was found to exhibit no detectable motion, allowing us to focus on rotation around it. |