Vibrationally Resolved Photoelectron Imaging of Platinum Carbonyl
Anion Pt(CO)n- (n=1-3): Experiment and Theory
Zhiling Liu,1 Hua Xie,1 Zhengbo Qin,1 Ran Cong,1 Xia Wu,1 Zichao
Tang,1,a) Xin Lu,2,b) and Jian He3
1
State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical
Physics, Chinese Academy of Sciences, Dalian 116023, China
2
State Key Laboratory of Physical Chemistry of Solid Surface & Fujian Provincial
Key Laboratory of Theoretical and Computational Chemistry, Department of
Chemistry, College of Chemistry and Chemical Engineering, Xiamen University,
Xiamen 361005, China
3
The Institute of Physics and Mechanical & Electrical Engineering, The laboratory of
Analysis Instrument, Xiamen University, Xiamen 361005, China
a)Electronic mail: zctang@dicp.ac.cn
b)Electronic mail: xinlu@xmu.edu.cn
1
The band labeled asterisk in the PES of Pt(CO)3A remarkable spot locates at the center of the photoelectron image of Pt(CO)3-,
corresponding to the weak mysterious band labeled asterisk in the PES of Pt(CO)3-.
The signal is near the cut-off energy (2.331eV) for our electron detector. When we
systematically varied the mass gate timing to select the rising edge, middle and failing
edge of the Pt(CO)3- mass peak, the signal still exists, accompanied by the
increasement in the relative intensity.
The feature labeled asterisk can’t be assigned based on single-photon
photodetachment. The ground state of Pt(CO)3- is D3h (2A2″, D3h) with a valent
electron configuration …2e″4 7a1′2 8e′4 3a2″1. Upon photodetachment, the singly
occupied MO of the doublet anion is depleted and becomes the LUMO of the neutral,
resulting in neutral ground state with a valent electron configuration …2e″4 7a1′2 8e′4,
as shown in TABLE S4. Photodetachment on the degenerate 8e′ MO will generate the
lowest triplet state (3B1, C2v, due to Jahn-Teller effect) with a valent electron
configuration …9b22 2a22 4b12 14a12 15a11 5b11, which is at least 2.005 eV higher in
energy than the neutral ground state (TABLE 3). In Ganteför’s PESR1, R2, the first
band above ground state transition originates at about 3.4 eV, in reasonable agreement
with our calculated the lowest triplet (3B1, C2v) state.
Consequently, there are no excited states of Pt(CO)3 predicted to lie at the
energies range from 1.3 eV to 2.331 eV. We explored several possible alternative
sources of this band, according to our experimental environment. Several potential
nearly mass-degenerate ion beam contaminants were taken into account, including
2
PtFeCO and HPt(CO)3 (an alcohol structure [Pt(CO)2CO-H], a formaldehyde
structure [H-COPt(CO)2] and a platinum hydride structure [H-Pt(CO)3], shown in FIG.
S1). The DFT calculations were carried out using the B3LYP functional with the Pt,
Fe/Stuttgart+2f1g /C, O, H/aug-cc-pVTZ basis sets. The EAs and VDEs for the most
stable of these contaminants are summarized in TABLE S5. Note that the EA of
PtFeCO is 1.59 eV, which could be masked by other dominant peaks. However,
PtFeCO could be ruled out due to the difference between the pattern of
experimentally observed mass spectrum and that of PtFeCO. For masses coincident
with anionic HPtCO3, the platinum hydride structure was found to be the most stable
of all isomers. For anion, the formaldehyde structure (1A' ground state) was calculated
to lie 0.308 eV above the platinum hydride structure, and the alcohol structure,
(CO)2PtCO-H- was found to lie 2.34 eV above the platinum hydride structure. The EA
of the platinum hydride structure is 2.52 eV, which is beyond our photon energy
(2.331 eV). Of all three isomers, only the EA (2.17 eV) of the formaldehyde structure
perfectly matches with the band, suggesting that the band nearly originating at ~2.2
eV in the PES of Pt(CO)3 may come from the detachment of HPt(CO)3- of
formaldehyde structure. It may be much more extended than it appears, according to
our calculated VDE (2.46 eV, as shown in TABLE S4) of the formaldehyde structure.
3
TABLE S1. Harmonic vibrational frequencies (in cm-1) and infrared intensities (in parentheses, in
km/mol) for PtCO0/-1.
PtCO-1
PtCO
a
R3.
b
R4.
c
R5.
d
R6.
e
R7.
Cal.
Expt.
Cal.
Expt.
2077 (633.9)
2065.5a/2056.8b/2052.0c
1926 (974.6)
1896.3a
579 (7.0,)
580.8b/550d/593e
539 (9.0)
405 (2.5×2)
412e
97 (75.5×2)
4
TABLE S2. Harmonic vibrational frequencies (in cm-1) and infrared intensities (in parentheses, in
km/mol) for Pt(CO)20/-1.
Pt(CO)2-1
Pt(CO)2
Cal.
Cal.
Expt.
B3LYP
CCSD(T)
2167 (9.0)
2171
2073 (1947.2)
2067
488 (0.1)
Expt.
B3LYP
CCSD(T)
2173a
1937 (0.0)
1953
2053.2b/2039.8c/2057.2d
1861 (2777.6)
1875
513
504 (0.0)
529
450 (0.0)
463
496 (1.3)
496
445 (0.0)
454
407 (0.0)
414
398 (138.6)
392
382 (3.6)
374
341 (0.3)
335
367 (24.6)
361
340 (0.0)
330
351 (0.0)
345
20 (0.5)
24
55 (2.6x2)
43
a
This work.
b
R3.
c
R4.
d
R5.
383.55c
5
1884.0b
TABLE S3. Harmonic vibrational frequencies (in cm-1) and infrared intensities (in parentheses, in
km/mol) for Pt(CO)30/-1.
Pt(CO)3-1
Pt(CO)3
Cal.
Expt.
Cal.
2120 (0.0)
2119a
1953 (0.0)
2060 (1287.3×2)
2044.0b/2038.1c/2049.0d
1886 (2063.2×2)
500 (12.2×2)
485.8c
526 (40.6×2)
448 (6.1)
447.5c
463 (0.0)
431 (0.0)
444a
439 (17.0)
335 (90.0×2)
348.5c
374 (22.6 ×2)
304 (0.0)
327 (0.0×2)
259 (0.0×2)
325 (0.0)
58 (0.2×2)
62 (0.2)
50 (0.8)
58 (0.1×2)
a
This work.
b
R3.
c
R4.
d
R5.
6
Expt.
1875.8b
TABLE S4. Ground states and low-lying states of Pt(CO)3- and Pt(CO)3.
species
symmetry final state and electronic configuration energy/eV
A2″…2e″4 7a1′2 8e′4 3a2″1
0.0
A1’…2e″4 7a1′2 8e′4
1.368
Pt(CO)3- D3h
2
D3h
1
C2v
3B
D3h
3
C2v
3A
2
2
2
2
1
1
1…9b2 2a2 4b1 14a1 15a1 5b1
3.373
Pt(CO)3
A2″…2e″4 7a1′1 8e′4 3a2″1
2
2
1
2
2
1
1…9b2 2a2 4b1 14a1 15a1 5b1
7
4.805
7.502
TABLE S5. Summary of calculated EAs and VDEs for possible contaminants in the Pt(CO)3PES.
species
Neutral ground state
PtFeCO
5
H-COPt(CO)2
2
Anion ground state
EA (eV)
VDE(eV)
4 +
Σ
1.59
1.74
1
2.17
2.46
1
2.52
2.83
1A'
1.42
1.56
A"
A'
H-Pt(CO)3
2A
Pt(CO)2CO-H
2A'
A'
1A
1
References:
(R1) Ganteför, G.; Icking-Konert, G. S.; Handschuh, H.; Eberhardt, W. Int. J. Mass.
Spect.Ion Proc. 1996, 159, 81.
(R2) Icking-Konert, G. S.; Handschuh, H.; Ganteför, G.; Eberhardt, W. Phys. Rev.
Lett. 1996, 76, 1047.
(R3) Liang, B. Y.; Zhon, M. F.; Andrews, L. J. Phys. Chem. A 2000, 104, 3905.
(R4) Manceron, L.; Tremblay, B.; Alikhani, M. E. J. Phys. Chem. A 2000, 104, 3750.
(R5) Kuendig, E. P.; McIntosh, D.; Moskovits, M.; Ozin, G. A. J. Am. Chem. Soc.
1973, 95, 7234.
(R6) Chatterjee, B.; Akin, F. A.; Jarrold, C. C.; Raghavachari, K. J. Chem. Phys.
2003, 119, 10591.
(R7) Okabayashi, T.; Yamamoto, T.; Okabayashi, E. Y.; Tanimoto, M. J. Phys. Chem.
A 2011, 115, 1869.
8
FIG. S1. Optimized structures of HPt(CO)30/-1 at B3LYP level. The Pt, C, O and H are shown in
blue, gray, red and white, respectively. Bond lengths in Å and bond angles in degree are given
above the bond, and the relative energy to the anion are given in square brackets in eV.
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Intensity (arb. unit)
1.0
1.5
2.0
Binding energy (eV)
FIG. S2. The photoelectron spectrum of Pt- at 532nm.
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