1. Wei Li, Mingfei Zhou Fudan University, Shanghai, China
Infrared Spectroscopic and Theoretical Study of the HCnO+ (n = 5-12) Cations
Wei Li, Mingfei Zhou
Fudan University, Shanghai, China
Talk FA09, 72th ISMS, June 2017

2. Content 1. Background 2. Experimental and Computational Methods
3. Results and discussion
4. Conclusions

3. Background Carbon chains and derivatives
Potential interstellar molecules
Highly active species
Reactive intermediates
H. Herrmann, et al. J. Atmos.Chem. 2000, 36, 231
D. L. Baulch, et al. J. Phys. Chem. 2005, 34, 757
P. Ehrenfreund, et al. Annu. Rev. Astron. Astrophys. 2000, 38, 427

4. Background Spectroscopic studies Mass spectrometry HCnO+ ions
Electronic spectra
HC7O+ cation
Rotational spectra
HC5O and HC7O radicals
HCnO (n = 1-9)
S. Mohamed, et al. J. Chem. Phys. 2005, 123,
A.C.Simmonett, et al. J.Phys.Chem.A.2009,113,11643
S. Peppe, et al. J. Phys. Chem. A. 2000, 104, 5817
A. Chakraborty, et al. Mol. Phys. 2016, 114, 2794

5. Experimental method AB+ ~ l IR photodissociation spectrum
G. J. Wang, et al. J. Phys. Chem.A. 2012, 116, 2484
G. J. Wang, et al. Sci. China: Chem. 2014, 57, 172

6. Computational method Geometries and frequencies B3LYP-D3 AUG-cc-pVTZ
Scale factor: 0.968
Bonding analyses
Natural orbital analysis(NBO)
Adaptive natural density partitioning(AdNDP)
A. E. Reed, et al. J. Chem. Phys. 1985, 83, 735
D. Y. Zubarev, et al. Phys. Chem. Chem. Phys. 2008, 10, 5207

7. Mass spectrum
C + CO/H2/He
HCnO+ (n = )
[HCnO·CO]+ (n = )

8. IR spectra of [HCnO·CO]+
C-C
C-O
C-H
n = 5
n = 7
n = 9
n = 11
n = 6
n = 8
n = 10
n = 12

9. Low energy isomers HC5O+ (e) 1A1 ; C2v; ΔE = 58.7 kcal/mol
(d) 3Σ-; C∞V; ΔE = 56.7 kcal/mol
(c) 1A ; Cs; ΔE = 55.9 kcal/mol
(b) 1A ; Cs; ΔE = 54.7 kcal/mol
(a) 1Σ+; C∞V; ΔE = 0.0 kcal/mol

10. Little effect of tagging CO
(b) 1Σ+ [HC5O]+ (C∞V)
(a) 1A [HC5O·CO]+ (Cs)

11. Geometries and NBO analyses
HCnO+ (n = 5, 7, 9, 11); 1Σ+; C∞V
Polyyne-like structures
n = 7
n = 9
n = 11
Bond lengths (Å) and Wiberg bond orders ( in brackets) are showed under the structures.

12. Geometries and NBO analyses
HCnO+ (n = 6, 8, 10, 12); 3Σ-; C∞V
allene-like structures
n = 8
n = 10
n = 12
Bond lengths (Å) and Wiberg bond orders ( in brackets) are showed under the structures.

13. AdNDP orbitals
1×1c-2e LPs
ON=|1.98e|
2×3c-2e π
ON=|2.00e|
2×4c-2e π
ON=|2.00e|
6×2c-2e σ
ON=|1.99e-2.00e|
2×6c-2e π
ON=|2.00e|
The adaptive natural density partitioning analyses (AdNDP) of HC5O+

14. Conclusions
The HCnO+ (n = ) cations are characterized to be linear carbon chain derivatives terminated by hydrogen and oxygen.
The HCnO+ cations with odd number of carbon atoms have closed-shell singlet ground states with polyyne-like structures, while those with even number of carbon atoms have triplet ground states with allene-like structures.
The AdNDP bonding analyses indicate that there are pairs of multiple-center-two-electron delocalized π bonds on the CnO chains, along with the localized two-center-two-electron  bonds.

15. Acknowledgment Advisor: Prof. Mingfei Zhou Zhou Group:
Dr. Guanjun Wang
Jiaye Jin

16. Thank you very much for your attention!

17. Q&A

18. Simulated spectra n=5 n=7 Structure Experimental (black) and simulated
(c)1Σ+ [HC5O]+ (C∞V)
n=5
(b) 1A [HC5O·CO]+ (Cs)
(c)1Σ+ [HC7O]+ (C∞V)
n=7
Experimental (black) and simulated
(red) vibrational spectra
(b) 1A [HC7O·CO]+ (Cs)
Structure

19. Simulated spectra n=9 n=11 Structure
(c)1Σ+ [HC9O]+ (C∞V)
n=9
(b) 1A [HC9O·CO]+ (Cs)
n=11
(c)1Σ+ [HC11O]+ (C∞V)
Experimental (black) and simulated
(red) vibrational spectra
(b) 1A [HC11O·CO]+ (Cs)
Structure

20. Simulated spectra n=6 n=8 Structure Experimental (black) and simulated
(d)3Σ- [HC6O]+ (C∞V)
n=6
(c)3A [HC6O·CO]+ (Cs)
(b)3Σ- [HC6O·CO]+ (C∞V)
n=8
(c)3Σ- [HC8O]+ (C∞V)
Experimental (black) and simulated
(red) vibrational spectra
(b)3A [HC8O·CO]+ (Cs)
Structure

21. Simulated spectra n=10 n=12 Structure
(c)3Σ- [HC10O]+ (C∞V)
n=10
(b)3A [HC10O·CO]+ (Cs)
(c)3Σ- [HC12O]+ (C∞V)
n=12
(b)3A [HC12O·CO]+ (Cs)
Experimental (black) and simulated
(red) vibrational spectra
Structure

22. AdNDP analyses with evev n
The adaptive natural density partitioning analyses (AdNDP) of HC6O+
The adaptive natural density partitioning analyses (AdNDP) of HC8O+
The adaptive natural density partitioning analyses (AdNDP) of HC10O+
The adaptive natural density partitioning analyses (AdNDP) of HC12O+

23. AdNDP analyses with odd n
The adaptive natural density partitioning analyses (AdNDP) of HC7O+
The adaptive natural density partitioning analyses (AdNDP) of HC9O+
The adaptive natural density partitioning analyses (AdNDP) of HC11O+