Chemistry Reference
In-Depth Information
Phosphine-Coordinated Pure-Gold Clusters:
Diverse Geometrical Structures and Unique
Optical Properties/Responses
Katsuaki Konishi
Abstract Synthetic techniques, geometrical structures, and electronic absorption
spectra of phosphine-coordinated pure-gold molecular clusters (PGCs) accumu-
lated over 40 years are comprehensively collected especially for those with unambi-
guous X-ray crystal structures available. Inspection of the electronic absorption
spectra from geometrical aspects reveals that their optical properties are highly
dependent on the cluster geometries rather than the nuclearity. Recent examples of
unusual clusters that show unique color/photoluminescence properties and their
utilization for stimuli-responsive modules are also presented.
Keywords Absorption spectrum
Chromism
Gold cluster
Optical property
Phosphine
Photoluminescence
Stimuli-responsive materials
Contents
1 Introduction . . ................................................................................. 50
2 Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3 Synthesis . . . . . . ................................................................................ 52
3.1 Direct Syntheses from Gold Complex Ion or Bulk Gold . . . . . . . . ..................... 54
3.2 Post Synthesis . . ......................................................................... 58
4 Geometrical Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.1 Centered Polyhedral Clusters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
4.2 Non-centered Polyhedral Clusters . . . . ................................................. 67
4.3
Exo
-attached Polyhedral Clusters (core+
exo
Type) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5 Optical Properties ............................................................................. 71
5.1 Electronic Absorption Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
5.2 Photoluminescence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
5.3 Gold Clusters as Stimuli-Responsive Chromic Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
