Chemistry Reference
In-Depth Information
Fig. 6 (a) Typical reaction where the initial crude product (control -
top
MALDI-MS spectrum)
was subjected to mild thermochemical treatment to obtain a product (
bottom
MALDI-MS spec-
trum) where Au
67
is a major product and other sizes are diminished in signal. Peaks with asterisk
denote fragments. (b)Au
67
(SR)
35
purification separating larger clusters: MALDI spectra showing
the systematic separation (top to bottom) of Au
102
clusters from a mixture of Au
25
,Au
67
, and
Au
102
. The final product (
bottom
) is further used to separate the clusters lower in mass than
Au
67
(SR)
35
.(c)Au
67
(SR)
35
purification separating smaller clusters: Continuation of the separation
process to remove sizes smaller than Au
67
(SR)
35
. Inset to part a: MALDI spectra of the pure
Au
67
(SR)
35
with two different ligands, phenylethanethiol (
top
) and hexanethiol (
bottom
) taken at
very high laser fluence. At high laser fluence, even minor amounts of impurities or other core-size
clusters will show higher signal intensity. Reprinted with permission from [
4
]. Copyright 2013
American Chemical Society
