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Tao Chen

Profilbild av Tao Chen

Om mig

Tao Chen is a researcher working at the Department of Theoretical Chemistry and Biology. His research focuses on the theoretical study of fragmentation, isomerization, molecular growth and infrared features of large complex organic compounds in the interstellar medium (ISM), including polycyclic aromatic hydrocarbons (PAHs), nanotubes, fullerenes, and their derivatives and clusters.  

As the sensitivities of detecting instruments continue to improve and the spectral coverage continues to widen, these complex molecules have been or will be discovered by infrared and millimeter observations. The chemical reactions that lead to the formation of such large molecules will provide invaluable clues to the question of the origin of life. Moreover, his study also serves as useful probes to the physical conditions of the ISM, providing measurements of the density, temperature, and kinematics of the interstellar clouds. 

Recent results

2020-12-11 Paper "Molecular bending as a vital step toward transforming planar PAHs to fullerenes and tubular structures" is published by A&A. Available here.

2020-02-17 Paper "On Carbon Nanotubes in the Interstellar Medium" is published by MNRAS. Available here.

2019-12-15 Paper "Fragmentation and isomerization of polycyclic aromatic hydrocarbons in the interstellar medium: coronene as a case study" is accepted by A&A. Available here.

2019-10-13 Paper "The infrared bands of polycyclic aromatic hydrocarbons in 1.6 – 1.7 μm region" is accepted by A&A. Available here.

2019-09-19 Paper "Synthesizing carbon nanotubes in space" is accepted by A&A. Available here.

Calculated dissociation energies for H-loss and reaction barrier for formation of closed-structure (hydrogenated nanotube) from terphenyl.

2019-04-08 Paper "Formation of polyynes and ring–polyyne molecules following fragmentation of polycyclic aromatic hydrocarbons" is published by MNRAS. Available here.

Molecular dynamics simulations of the fragmentation processes of anthracene (top), tetracene (middle) and pentacene (bottom) at 5000 Kelvin.

2019-02-13 Paper "Temperature effects on anharmonic infrared spectra of large compact polycyclic aromatic hydrocarbons" is published on A&A. Available here

2019-01-10 Paper "Laboratory photo-chemistry of covalently bonded fluorene clusters: observation of an interesting PAH bowl-forming mechanism" is published on APJ. Available here

2018-10-19 Paper "Formation of Covalently Bonded Polycyclic Aromatic Hydrocarbons in the Interstellar Medium" is published on APJ. Available here.

A covalently bonded system is formed within a picosecond without any external energy or initial velocity.

2018-10-11 Paper "Anharmonicity and the infrared emission spectrum of highly excited polycyclic aromatic hydrocarbons" is published on A&A. Available here.

Temperature effects on the IR spectrum of pyrene in 12 μm region and comparison with experimental data (blue curve in the top panel) (Cook et al. 1996). The red curve represents the calculated anharmonic emission spectrum after absorbing a 5 eV photon. The blue sticks are the fundamental and combination bands calculated at 0 K, i.e., without temperature effects considered in the calculations.

2018-10-2 Paper "Fully anharmonic infrared cascade spectra of polycyclic aromatic hydrocarbons" is published on JCP. Available here.

2018-10-1 Paper "The Carrier of 3.3 μm Aromatic Infrared Bands: Anharmonicity and Temperature Effects on Neutral PAHs" is published on APJS. Available here.

The comparison between high-resolution low-temperature (~20K) gas-phase experimental IR spectrum and the calculated anharmonic spectra with different level of combination bands of pyrene. The calculated spectra are convolved with a Gaussian profile (FWHM = 0.5 cm−1) to approximately match the resolution of the experimental data. 

2018-08-17 Paper "Laboratory Photochemistry of Pyrene Clusters: An Efficient Way to Form Large PAHs" is published on ApJ. Available here.

Mass spectrum showing the region of pyrene dimer (m/z=404) without and with 0.2 and 1.0 mJ laser irradiation. A peak separation is equivalent to a hydrogen loss from the system. 

Calculated reaction pathways showing the formation of covalently bonded PAH and large planar PAH through dissociations of hydrogens in a pyrene dimer.

2018-01-16 Paper "From planes to bowls: Photodissociation of the bisanthenequinone cation" is published on CPL. Available here.

Mass spectrum of bisanthenequinone cation (Bq+) before (blue curve) and after irradiation (black curve) by 626 nm laser. Bowl shape molecules ([Bq-2CO]+) are formed following the laser irradiation.  

Profilbild av Tao Chen