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

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

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

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, 234301 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

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

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

Mass spectrum C + CO/H2/He HCnO+ (n = 5 - 12) [HCnO·CO]+ (n = 5 - 12)

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

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

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

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.

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.

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+

Conclusions The HCnO+ (n = 5 - 12) 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.

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

Thank you very much for your attention!

Q&A

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

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

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

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

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+

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+