air–water interface (Fig. 17). Surface pressure–area (p–A)
isotherms, UV/vis spectroscopy, XRD, X-ray photoelectron spec-
troscopy, FTIR, and polarized IR spectroscopy, as well as lumi-
nescence properties in films were successfully investigated.
A 47-layer film of the complex with R¼C 6 H 5 n¼14 (see Fig. 17)
was found to exhibit a low-energy emission band at 693 nm,
which is indicative of the presence of PtPt interactions and/
orp–pstacking as a result of the close molecular packing in the
ordered arrangement, as revealed by the characterization in
the p–Aisotherm and XRD pattern. The origin of these low-
energy emission bands was tentatively assigned as MMLCT
230(^220210)
200
190
180
–240
–250
Ios
/ nA
–260
–270
0 20
off
on
on
off
5 μm t/s 40 60 80
FIG. 16. Structure–color correlation table of Pt(II) complexes (left).
The SEM image of a bottom-contact FET device with nanosheets as
semiconducting materials is shown (center). Transient conductivity
measurement of the FET device (right). The transient channel current
was recorded with a light switching on and off every 5 s in a 90-s period.
Reproduced with the permission of Wiley-VCH ( 258 ).
N
NN
X = PF 6
n = 1; R = C 6 H 5
n = 1; R = C 6 H 4 - p-CF 3
n = 1; R = C 6 H 4 - p-N(C 6 H 5 ) 2
n = 14; R = C 6 H 5
l= 1.8 nm
H 2 n+1Cn CnH 2 n+1
- X–
d spacing
3.4 nm
NN
25º
Pt Pt Pt Pt Pt
Pt Pt Pt Pt Pt
C
C
R
Pt
FIG. 17. Selected Pt(II) complexes (left), as described by Yamet al.
Proposed structure of self-assembled films withn¼14, and a chloride
replacing the acetylide anion (right). Reproduced with the permission
of Wiley-VCH ( 259 ).
PHOTOPHYSICS OF MOLECULAR ASSEMBLIES 79