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Published on: May 28, 2014
High quantum yield molecular bromine photoelimination from mononuclear platinum(IV) complexes
Alice Raphael Karikachery1, Han Baek Lee, Mehdi Masjedi
1University of Missouri, Columbia, Missouri 65211, USA.
Inorganic Chemistry
|March 15, 2013
Summary
Platinum(IV) complexes release bromine molecules upon light exposure, with high efficiency in both solid and solution states. This photoelimination process is endothermic and may involve a radical-like excited state.
Area of Science:
- Inorganic Chemistry
- Photochemistry
- Materials Science
Background:
- Platinum complexes are crucial in catalysis and medicine.
- Understanding their photochemical properties is key to developing new applications.
- Photoinduced molecular bromine elimination from Pt(IV) complexes is a novel area of research.
Purpose of the Study:
- To investigate the photochemical behavior of Pt(IV) complexes.
- To quantify the efficiency of molecular bromine photoelimination.
- To elucidate the mechanism and thermodynamic properties of this process.
Main Methods:
- Synthesis of trans-Pt(PEt3)2(R)(Br)3 complexes (R = Br, aryl, polycyclic aromatic).
- Photoelimination quantum yield determination.
- Calorimetry measurements and Density Functional Theory (DFT) calculations.
- Solution trapping experiments using 2,3-dimethyl-2-butene.
Main Results:
- High quantum yields (up to 82%) for molecular bromine photoelimination were observed.
- Photoelimination occurred in both solid and solution phases.
- Thermodynamic analysis indicated endothermic and endergonic processes (2-22 kcal/mol Br2).
- Evidence suggests a radical-like excited state precursor to bromine elimination.
Conclusions:
- Pt(IV) complexes can efficiently photoeliminate molecular bromine.
- The process is thermodynamically uphill, requiring light energy input.
- A radical-like excited state is implicated in the bromine elimination mechanism.
- These findings open avenues for light-driven bromine release applications.
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