Chemistry Reference
In-Depth Information
6 Concluding Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Abbreviations
Ar Aryl
AZS Alizarinsulfonate
Bu Butyl
DCM Dichloromethane
dppb Bis(diphenylphosphino)butane
dppe Bis(diphenylphosphino)propane
dpph Bis(diphenylphosphino)hexane
dppm Bis(diphenylphosphino)methane
dppo Bis(diphenylphosphino)octane
dpppe Bis(diphenylphosphino)pentane
equiv
Equivalent(s)
Et
Ethyl
i
-Pr
Isopropyl
Mes
Mesityl
PL
Photoluminescence
py
Pyridyl
t
-Bu
Tert
-butyl
Tol
Tolyl
1
Introduction
During the last several decades, the chemistry of ligand-protected noble metal
nanoparticles/clusters has progressed rapidly. Fundamental aspects have been
addressed and practical uses have been found in diverse research areas including
medicine, electronics, and catalysis [
1
-
6
]. The most prominent property of conven-
tional gold particles (diameter
2 nm) is localized surface plasmon bands, which
have been widely exploited for biomedical applications [
4
,
7
]. On the other hand,
for very small clusters in the subnanometer size regime (
d
~1 nm or less), such
plasmon resonances disappear and discrete electronic transitions emerge which are
characteristic molecular properties [
8
-
12
]. Thus, it is now well recognized that the
subnano-sized clusters are virtually different from conventional colloidal particles/
clusters in terms of electronic structures and properties [
8
]. Especially in recent
years, much attention has been paid to their unique optical properties since the
discovery of photoluminescence of some ultrasmall gold clusters in this size regime
[
13
]. The reactivity and catalysis of the ultrasmall metal entities have also attracted
great interest [
5
].
>
