Transcript Structures, Photoluminescence, and Reversible

Structures, Photoluminescence, and
Reversible Vapoluminescence
Properties of Neutral Platinum(II)
Complexes Containing Extended πConjugated Cyclometalated Ligands
Steven C. F. Kui, Stephen Sin-Yin
Chui, Chi-Ming Che,* and
Nianyong Zhu
presenter : 戴如妮
J. Am. Chem. Soc. 2006, 128, 8297-8039
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Supramolecular Coordination Chemistry
Hydrogen bonding
p-p interaction
Metal to ligand binding
van der Waals forces
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Holliday, B. J. et. al. Angew. Chem. Int. Ed. 2001, 40, 2022-2043.
Supramolecular Assembly of Polyhedra
C-H … p
p…p
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Stang, P. J.; Olenyuk, B. Acc. Chem. Res.; 1997, 30, 502-518
(C^N^N)Pt(II) Complex Containing
a Monoaza-15-Crown-5
N
O
O
H3C
N Pt
N
Mg
O
O
HC^N^N = 4-(4-tolyl)-6-phenyl-2,2'-bipyridine
CH3CN (1.2x10-5M)
Photoinduced Electron Transfer (PET)
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Yang, Q. -Z. et. al. Inorg. Chem. 2004, 43, 5195.
Organoplatinum Crystals for
Gas-Triggered Switches
Me2HN
Cl
Pt
NHMe2
Me2HN
Cl SO
2
Pt
NHMe2
+ SO2
- SO2
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Koten, G. V. et. al. Nature. 2000, 406, 970-974.
Volatile Organic Compounds ( VOCs )
Vapoluminescence
a)
b)
(i) the facile reversible change of the molecular structure of the luminophore
(ii) alterations in the molecular packing when the analyte molecule enters
and exits the crystal structure of the luminescent sensory material.
a) Eisenberg, R. et. al. J. Am. Chem. Soc. 2004, 126, 16841-16849.
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b) William, B. C. et. al. J. Am. Chem. Soc. 2004, 126, 1594-1595.
Crystal Structure of
[(C^N^C)2Pt2(μ-dppm)]
antiC
Pt
P
Ph
Ph
N
Ph Ph
P
Pt
C
C
CHCl3
C
N
B
[(C^N^C)2Pt2(μ-dppm)]
[(C^N^C)2Pt2(μ-dppm)]
[(C^N^C)2Pt2(μ-dppm)]∙CHCl3
P(1)-Pt(1)-N(1) = 171.2(2)
P(2)-Pt(2)-N(2) = 174.6(3)
P(1)-Pt(1)-N(1) = 170.6(2)
P(2)-Pt(2)-N(2) = 172.4(2)
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Che, C.-M. et. al. Organometallics. 2001, 20, 2477-2486.
Rourke’s Method
[(R-C^N^C)Pt(DMSO)]
R
R
R
N
R
C
Pt
K2PtCl4
C
C
Cl
AcOH
refluxed
for48 h
N
C
C
Cl
N
Hot DMSO
N
C
H2O
Pt
C
N
Pt
S O
C
C
Pt
L
C
[(R-C^N^C)Pt(L)]
2
R
R = H, 2a; Ph, 2b; 4-BrC6H4, 2c; 3,5-F2C6H3, 2d
Ph
Ph
N
C
Pt
S O
+ PPh3
C
CH2Cl2
N
N2
C
12 h
Ph
2b
Pt
S O
2
Pt
P
C
Ph Ph
3
R
R
N
[(Ph-C^N^C)Pt(PPh3)]
+ dppm
CH2Cl2
N2
12 h
C
Pt
P
Ph
Ph
R
N
C
C
[(R-C^N^C)2Pt2(μ-dppm)]
N
Pt C
P Ph
Ph
R = H, 4a; Ph, 4b; 4-BrC6H4, 4c; 3,5-F2C6H3, 4d
4
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Rourke, J. P. et. al. Organometallics. 2000, 19, 1355-1364.
Simulated 31P{1H}NMR Spectra of 4b in
Syn- and Anti(d, 3JP-195Pt = 29.0 Hz )
syn(d, 2JP-195Pt = 84.41 Hz)
( d, 2JP-P = 34.91 Hz )
( d, 1JP-195Pt = 4236.36 Hz )
anti-
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Simulated based on AA′XX′ system, 31P NMR (162 MHz,CD2Cl2)
31P{1H}
NMR Spectrum of 4b in CD2Cl2
Experiment
syn-
( d, 1JP-195Pt = 4251.0 Hz )
Isotope
Natural
abundance/%
190Pt
0.01
192Pt
0.79
194Pt
32.9
195Pt
33.8
196Pt
25.3
198Pt
7.2
Ph
Spin of nucleus
C
Pt
P
Ph
Ph
1/2
Ph
N
C
C
N
Pt C
P Ph
Ph
4b
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The Structures of 2b, 3, 4b
C
Ph
Ph
N
N
Pt
S O
C
C
Ph
2b
Ph
C
Pt
Ph P
Ph
Ph
N
C
C
Pt
P
C
Ph Ph
3
N
Pt C
P Ph
Ph
4b
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UV-Vis Absorption and Solid-State
Emission Spectra of 2b, 3, and 4b at R. T.
charge transfer
ligand-ligand transition
metal-ligand charge transfer
ligand p*
s*
metal d
n
metal
d
n
d-d transition
ligand p
s
ligand-metal charge transfer
metal-metal (d-d) transition
2b ~ excimeric (A-A*) 3ππ* excited states
3 ~ intraligant 3ππ*excited states
4b ~ excimeric 3ππ*excited states
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Emission Spectra of 2b & 4b
a)
b)
2b
in the solid state at 77 K
in 2-MeTHF at 77 K
4b
in the solid state at 77 K
in 2-MeTHF at 77 K
Ph
C
Ph
Pt
Ph P
Ph
Ph
N
C
C
Pt C
P Ph
Ph
N
C
Pt
S O
N
C
4b
2b
Vibronic coupling – interaction between electronic and vibrational
modes, increase intensity
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Emission Spectra of 3
Ph
N
C
Ph
Pt
P
C
Ph Ph
3
Emission spectra of 3 in the solid state at room temperature, 77
K, and as a glassy solutionin 2-MeTHF at 77 K
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The Emission Spectra of 4b
at Various Temperature
523 nm
566 nm
non - emission
Ph
C
Pt
P
Ph
Ph
Emission spectra of 4b in 2-MeTHF solution at 103-263 K
Ph
N
N
C
C
Pt C
P Ph
Ph
4b
(i) the molecular motion of the flexible Pt-P-CH2-P-Pt unit
(ii) the presence of a low-lying non-emissive d-d excited state
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Solid 4a under Ambient Light and under
UV Light Irradiation
a)
b)
anbient
light
UV light
Solid 4a under ambient light and under UV light irradiation (350 nm). (a) Orange crystals
of 4a upon exposure to air. (b) A reversible vapoluminescence for the desolvated form of
4a within 1 min of being exposed to CHCl3 vapor.
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Vapoluminescent Behavior of 4a
Ivoc is the emission intensity
of desolvated 4a upon
exposure to VOC under
saturation conditions
Idesolvate is the emission
intensity of desovated 4a
H
C
Pt
P
Ph
Ph
H
N
C
C
N
Pt C
P Ph
Ph
4a
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The Crystal Structure for 2a
H
N
C
Pt
S O
2a
C
Perspective view of 2a with omission of hydrogen atoms
(left) and the head-to-tail pairs molecular orientation (right).
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The Crystal Structures for 2b & 2c
2b.CHCl3
2c.CH2Cl2
Br
N
C
Pt
S O
2b
C
N
C
Pt
S O
C
2c
Perspective view of 2b·CHCl3 & 2c·CH2Cl2 with the omission of hydrogen atoms.
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Perspective View of Syn - and Anti 4a.6CHCl3.C5H12
H
C
Pt
Ph P
Ph
N
H
C
C
N
Pt C
P Ph
Ph
syn -
C
Pt
Ph P
Ph
N
C
Ph Ph
P
Pt
C-H…π
C-H(solvent)…π
C-H…X
C
C
N
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anti -
Porous Molecular Structure of
4a·6CHCl3·C5H12
synanti-
solvent channels
6.5 Å X 4.3 Å
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The Structures of 4c & 4d
syn - 4c·3CH2Cl2
anti - 4d·2CHCl3
F
solvent channels
F
Br
solvent channels
7.4 Å X 2.8 Å
Br
C
Pt
Ph P
Ph
C
Pt
P
Ph
Ph
N
C
C
4.6 Å X 2.0 Å
N
C
Ph Ph
P
Pt
N
C
C
N
Pt C
P Ph
Ph
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F
4c
4d
F
Compared with PXRD of Structures of
Solvated and Desolvated 4a
loss of solvent
2q = 5.297o
Volume = 7374 Å3
Ewald Sphere
2q = 5.877o
Volume = 6188 Å3
(hkl)
2q
q
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http://ruppweb.dyndns.org/xray/tutorial/ewald.htm
Packing Diagram of Desolvated 4a
H
C
Pt
Ph P
Ph
H
N
C
C
N
Pt C
P Ph
Ph
4a
layer of
syn-molecules
layer of
anti-molecules
layer of
syn-molecules
layer of
anti-molecules
layer of
syn-molecules
Molecular packing within desolvated 4a viewed from the c-axis
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The Vapoluminescent Properties
for Solvated & Desolvated 4a
loss of solvent
ΔG = ΔH –T .ΔS
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Conclusions
• Mononuclear and dinuclear cyclometalated
[(R-C^N^C)Pt-L] complexes were prepared and
structurally characterized.
• Accessible solvent channels and the presence of weak
and reversible non-covalent C-H … π, π … π,C-H…X,
and X…X interactions account for the vapoluminescent
behavior of 4a.
• The sensitivity of the emission properties of squar
planar Pt(II) complexes is the basic operating principle
behind their application as molecular VOC sensory
materials.
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Excimers ~~ excited-state dimers
excimeric (A-A*)
3ππ*
1
S1
MLCT
intersystem
crossing
3
hv
A + eA++ 2e- + A
A+ + 2eA-A* + e-
S0
MLCT T
1
kr
(R-C^N^N) Pt(R)
http://en.wikipedia.org/wiki/Excimer
knr
Vibronic Coupling
1.
When there is an atom common to the two vibrations.
2.
Bending vibrations requires a common bond between
the vibrating groups.
3.
The stretching bond forms one side of the angle that
varies in the bending vibration.
4.
The coupled groups have individual energies that are
approximately equal.
Is a short-lived dimeric molecule formed from two
species, at least one of which is in an electronic
excited state. Excimers are often diatomic and are
formed between two atoms or molecules that
would not bond if both were in the ground state.
The lifetime of an excimer is very short, on the
order of nanoseconds.The excimeric emission is
red-shifted relative to the emission from the
compound monomers
Rietveld Method for the Desolvated
Structutre of 4a
2q
A graphical plot of the final cycle of Rietveld refinement for the desolvated structutre of 4a
(red cross — experimental data point, green line — calculated data, and magenta line —
the difference plot between experimental and calculated data points).
The Seven Crystal Systems
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