Ultrafast Reaction Mechanism in Perovskite Bases Photocatalytic C-C Coupling

Jan. 21, 2020

Photoexcited perovskite nanocrystals (NCs) can initiate photo-redox reactions by reducing and oxidization various substrates on ultrafast timescale. The lifetime of the excited nanocrystals limits the subsequent reactive pathways.

Scientific Achievement

We observed an ultrafast electron transfer (~50 ps) from CsPbBr3 NCs to 2-bromoacetophenone and hole transfer (~70 ps) to an in-situ formed enamine or cocatalyst, resulting in a charge separated state with ~0.8 μs lifetime that allows photogenerated radical intermediates to couple.

Significance and Impact

Carbon-carbon (C-C) bond formation is a highly desirable chemical transformation. New types of catalyst that can activate small molecules are highly sought after. NC photo redox catalyst offers advantages over molecular homogenous catalyst.

Research Details

  • Transient absorption (TA) measurements with and without presence of substrates and co-catalyst
  • Photo-excited NCs can both reduce and oxidize the reagents forming long-lived radical species

DOI: 10.1021/acsenergylett.9b02714

Related People

Matthew Beard
National Renewable Energy Laboratory

Yong Yan
San Diego State University

Four small charts Schematic of molecules