Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10557270 | Microchemical Journal | 2005 | 9 Pages |
Abstract
Host/guest interactions of cyclophane/anthracene (C/A) and cyclophane/9-fluorenone (C/F) complexes in dichloromethane, where the cyclophane molecule is the host, are investigated. The stability constants, log Ka, for the C/A and C/F complexes are determined by absorption and fluorescence spectroscopy. For the C/A system, log Ka is 4.2±0.2 as determined from absorption (at 325 nm) and emission (at 382, 403 and 427 nm) spectroscopic data. The analogous measurements yield 3.6±0.2 from absorption (at 309 nm) and emission (at 505 nm) spectroscopic data for the C/F system. Heats of formation of these complexes were determined by measuring the complex association constants at 25, 29 and 32 °C. These results reveal that binding of the anthracene guest by this cyclophane molecule is thermodynamically favored over that for a 9-fluorenone guest. Excited state lifetimes of these systems are also determined.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Mark O'Brien, Rachelle Smalley, Augustine Amonge, Scott Raber, Andrew Starosota, Thandi Buthelezi, Richard A. Bartsch, Malgorzata Wegiel,