Bromine photoelimination from organoplatinum(IV) complexes
Metadata[+] Show full item record
With burgeoning population growth and widespread economic development world energy consumption is constantly on the rise. Currently most of our energy requirements are met through fossil fuels which are non-renewable. The production and use of these fuels also raise significant environmental concerns. Hence, renewable energy exploration is crucial to satiate the global energy demand and achieve sustainable growth. Coupling solar energy conversion storage cycle with small molecule activation promises renewable and greener fuel technology. Hence, there has been great interest in photochemical water splitting for the production of hydrogen and oxygen. But the four electron oxidation of water is difficult and currently not very economical. Alternatively, light driven endergonic hydrogen halide (HX) splitting, a more facile two electron process is also being explored. Photolytic halide elimination from high valent late transition metal centers like platinum (Pt), gold (Au) and rhodium (Rh) is a key step in designing HX splitting cycles. A high quantum yield ([Phi]) for the X?�� photoelimination step is crucial for designing efficient transition metal based HX splitting cycles. Endergonic X?�� photoelimination from transition metal complexes is rare and poorly understood though. We have discovered Br?�� photoelimination from [Sigma]-aryl platinum(IV) centers showing [Phi] as high as 82%. Endothermic and endergonic Br?�� elimination is observed with a radical-like excited state platinum precursor. Solution Br?�� elimination is thermally reversible though and alkene traps are required. Insights and inferences gained from this research can be extended to understand the splitting of water and other small molecules using photon. Efficient and economical water splitting would be crucial for the realization of a hydrogen economy as well as providing us with clean energy in a sustainable fashion.