| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1230729 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2013 | 6 Pages |
•The ms scale solvation dynamics of Pd-TCPP in ionic liquids is firstly studied.•The time-resolved phosphorescence emission spectra of Pd-TCPP are blue-shifted.•The polarity and structure of ILs affect UV–Vis and emission spectra of Pd-TCPP.
The phosphorescence behavior and solvation dynamics of Pd(II)-meso-tetra(4-carboxyphenyl)porphine (Pd-TCPP) in three imidazolium ionic liquids (ILs) has been studied. The phosphorescence excitation and emission position of Pd-TCPP are dependent on the polarity, constituent ions and structure of the ILs. The phosphorescence decay of Pd-TCPP in these ILs is bi-exponential, and the average lifetimes decrease in the following order: 0.844 ms in 1-butylimidazolium p-toluenesulfonate (HBIMTS) > 0.472 ms in 1-butylimidazolium trifluoromethane sulfonate (HBIMTfO) > 0.412 ms in 1-butyl-3-methylimidazolium p-toluenesulfonate (BMIMTS). The time-resolved phosphorescence emission spectra (TRPES) of Pd-TCPP display apparently blue-shifts with increasing time. The normalized Stokes shift correlation functions C(t) of Pd-TCPP in these ILs are mono-exponential, and the solvation relaxation times are 2.97, 47.7 and 12.1 ms in HBIMTfO, HBIMTS and BMIMTS, respectively. The solvation dynamics may be attributed to the collective motion of the ion pairs composed of imidazolium cations and counter anions to the area surrounding Pd-TCPP.
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