Abstract
The synthesis of atomically precise, large-sized Au
(SR)
nanoclusters (SR = thiolate) with
of 100 or more atoms has long been a challenge. In this work, we report the synthesis of Au
(Napt)
and Au
(IPBT)
nanoclusters (where Napt stands for 1-naphthalenethiolate and IPBT for 4-isopropylbenzenethiolate). Their optical absorption, single-electron charging, and femtosecond electron dynamics are investigated. Both Au
(Napt)
and Au
(IPBT)
exhibit multiple discrete absorption bands in their optical spectra owing to a quantized electronic structure in ultrasmall metal nanoclusters. Electrochemical analysis determines the precise HOMO-LUMO gaps of Au
(Napt)
and Au
(IPBT)
by single-electron charging. The electronic excited-state lifetimes of Au
(Napt)
and Au
(IPBT)
are determined by femtosecond transient absorption spectroscopy. The scaling relationship between the
and size (
) and the relationship of the excited state lifetime
the
of large-sized Au
(SR)
are discussed. The findings provide a fundamental understanding of large-sized metal nanoclusters, which will benefit their future applications in optics, electronics, and other fields.