J. Karpiuk
Nov 25, 2004
Citations
1
Influential Citations
31
Citations
Journal
Journal of Physical Chemistry A
Abstract
Crystal violet lactone (CVL) emits in aprotic solvents at room temperature single (A band, low polar solvents) or dual (A and B bands, medium and highly polar solvents) fluorescence. Strong solvatochromic shifts of both fluorescence bands prove significant charge redistribution in both emitting states (1CTA and 1CTB). Comparison with model compounds mimicking structural subunits of CVL, 6-dimethylaminophthalide (6-DMAPd), and malachite green lactone (MGL) shows that the A band is displayed from a polar excited state localized within the 6-DMAPd subunit (1CTA, μe ≅ 10.7 D), and the B band, from a highly polar excited state (1CTB, μe ≅ 25.2 D) formed after electron transfer from one of the dimethylaniline groups to 6-DMAPd moiety. The 1CTB state becomes accessible and is populated during solvation by a sufficiently polar environment. CVL phosphorescence strictly matches that of 6-DMAPd, indicating ISC to a triplet state localized on 6-DMAPd moiety in low polar solvents. In polar solvents, transient absorpti...