Fluorescence spectroscopy of jet-cFluorescence spectroscopy of jet-cooled phenylvinylacetylene in its ooled phenylvinylacetylene in its ground and first excited statesground and first excited states
Speaker: Ching-Ping LiuCoworkers: Josh Newby and Christian Müller
Advisor: Dr. Timothy ZwierDepartment of Chemistry, Purdue University
Motivation(1)Completing a series:
(2) Structural isomerization:
(3) C10H8 isomers: Alternatives to naphthalene in combustion, planetary atmospheres?
Previous detection: C4H2* + styrene, no spectral analysis
1-phenyl-1,3-butadiene
Sharp UV spectrum
phenylvinylacetylene phenyldiacetylene
Broad UV spectrum
Z-formE-form
Experiment
Laser beam
Collection mirrors
Collimating lens
To optics Housing
Supersonic expansion
Fluorescence excitation Dispersed fluorescence
PMT Monochromator / CCD
0 200 400 600 800 1000 1200 1400
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Arb
itra
ry U
nit.
Relative wavenumber / cm-1
Fluorescence excitation spectrum of PVA
150 200 250 300 350 400 450
0 200 400 600 800 1000 1200 1400 1600
0.0
0.2
0.4
0.6
0.8
1.0
Arb
itra
ry U
nit.
Relative wavenumber / cm-1
Single vibrational level dispersed fluorescence spectrum with the excitation of the origin band.
0248
01
01 4847
0132
0131
0128
0126
0125
0119
0130
02
01 4828 0
201 4826
02
01 4825
0123
0118
000
0448
Torsional progression
Cs symmetrya (in plane) modes: 1-33
a (out of plane) modes: 34-48
48Obs / cm-1
89
186
02480448
1
23
4
5
6
150 200 250 300 350 400 450
0 200 400 600 800 1000 1200 1400 1600
Arb
itrar
y U
nit.
Arb
itrar
y U
nit.
Arb
itrar
y U
nit.
Relative wavenumber / cm-1
0 200 400 600 800 1000 1200 1400 1600
Relative wavenumber / cm-1
266
222
254
326 334
400
Excite 222 cm-1
Excite 254 cm-1
Excite 266 cm-1
Excite 326 cm-1
Excite 334 cm-1
Excite 400 cm-1
Part of the FE spectra
SVLF spectra
1032
1132
1031
1131
FE spectra with various backing pressure of the carrier gases. (a) He 15 psi, and (b) He 40 psi, and (c) He 80 psi.
0 40 80 120 160 200 240
Relative wavenumber / cm-1
Arb
itrar
y U
nit.
(a)
(b)
(c)
Clusters
Cold band
Hot bands
v=0v=1
v=0v=1
v=2v=3
S1
S0
-2124
84158
232
104131
0 200 400 600 800 1000 1200 1400 1600
Relative wavenumber / cm-1
Arb
itra
ry U
nit.
- 21 cm-10
00
+ 24 cm-1000
+ 84 cm-1000
+ 158 cm-1000
+ 232 cm-1000
Single vibrational level dispersed fluorescence spectra of hot bands.
01
104847
1147
01
104846
1146
1144
1145
01
104847
1147
01
104845
01
104844
From v47=1
From v48=1
01
104645
01
104746
Duschinsky mixing
0 200 400 600 800 1000 1200 1400 1600
Relative wavenumber / cm-1
Arb
itra
ry U
nit.
+ 191 cm-1000
10
104746
12
104746
11
114746
+ 254 cm-1000
2246
2046
01
214846
+ 266 cm-1000
10
104745
11
1147451
101
10 474645
+ 400 cm-1000
2045
02
204645
2245
01
214645
SVLF spectra with excitation involving the out-of-plane modes.
0 200 400 600 800 1000 1200 1400 1600
Relative wavenumber / cm-1
Arb
itra
ry U
nit.
+ 104 cm-1000
1033
+ 222 cm-1000
+ 334 cm-1000
+ 539 cm-1000
1032
1132
1031
1131
1133
1028
1128
SVLF spectra with excitation involving the in-plane modes.
Arb
itrar
y U
nit.
Arb
itrar
y U
nit.
0 200 400 600 800 1000 1200 1400 1600
Relative wavenumber / cm-1
0 200 400 600 800 1000 1200 1400 1600
Relative wavenumver / cm-1
+ 931 cm-1
+ 948 cm-1
+ 1214 cm-1
+ 788 cm-1
+ 810 cm-1
+ 815 cm-1 + 1279 cm-1
+ 726 cm-1000
000
000
000
000
000
000
000
Single vibrational level dispersed fluorescence spectra.
0 200 400 600 800 1000 1200 1400
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Arb
itra
ry U
nit.
Relative wavenumber / cm-1
Fluorescence excitation spectrum of phenylvinlyacetylene
10
104746
2046 1
0104645
1032
1031
2045 1
030
1028
1026
1025
1019
000
2047
10
104745
1023
0 50 100 150 200
1147
01
104847
01
104846
01
104845
1033
2047
10
104746
Warm condition
01
104844
Hot bands
0 200 400 600 800 1000 1200 1400 1600 1800
Arb
itra
ry U
nit.
Relative wavenumber / cm-1
240 250 260 270 280
1C-R2PI and hole-burning spectraConformer or isomer A
Conformer or isomer B
Ho
le-b
urn
Ho
le-b
urn
Pro
be
Pro
be
S0
S1
S0
S1R2PI
UVHB
0 200 400 600 800 1000 1200 1400 1600
Relative wavenumber / cm-1
Arb
itra
ry U
nit.
+ 260 cm-1000
band000
)(6b01
)(101
)(1201
89
186
34
74 ?
The SVLF spectrum with the excitation in the unknown band.
Benzene-type modes
Conclusion• The analysis and assignments of the ground and first excit
ed states of phenylvinylacetylene are reported. The spectroscopy reveals Duschinsky mixing with four lower-frequency out-of-plane modes and IVR at high excess energy.
• The unknown band at 260 cm-1 above the origin in FE spectrum is probably originated from the Z isomer.
Future work
1. Quantitatively analyze Duschinsky mixing with four low-frequency out-of-plane modes.
2. Synthesize the Z isomer to get the spectral information for comparison with the E isomer.
3. UV-induced structural isomerization of E- or Z-PVA.
Acknowledgement• Advisor: Dr. Timothy Zwier• Group members: Dr. Christian Müller* Dr. Jasper Clarkson Esteban Baquero Alvin Shubert Nathan Pillsbury Tracy LeGreve Josh Newby* Chirantha Rodrigo Josh Sebree
• Dr. Daniel Lee
Funding: Taiwan Merit scholarship