Biomaterial Database

Electronic spectra and ionization potentials of a stable class of closed shell polycyclic aromatic hydrocarbon cations. 2001

J L Weisman, and T J Lee, and M Head-Gordon

Department of Chemistry, University of California, Berkeley, and Lawrence Berkeley National Laboratory, 94720, USA.

Due to their stability, closed shell polycyclic aromatic hydrocarbon (PAH) cations are possible candidates as carriers for some of the diffuse interstellar bands (DIBs). The electronic absorption spectra and ionization potentials of several closed shell PAH cations are determined in this study. We use density functional theory (DFT) at the BLYP/6-31G* level to determine the ionization potentials and thus confirm the stability of the PAH cations of interest. We use time-dependent density functional theory (TDDFT), again at the BLYP/6-31G* level, to calculate the vertical excitation energies and oscillator strengths of the PAH cations. We observe dominant single absorptions within the DIB spectral region of interest in all of the PAH cation spectra except for the smallest member of the series.

UI	MeSH Term	Description	Entries
D011084	Polycyclic Aromatic Hydrocarbons	Aromatic hydrocarbons that contain extended fused-ring structures.	Polycyclic Aromatic Hydrocarbon,Polycyclic Hydrocarbons, Aromatic,Polynuclear Aromatic Hydrocarbon,Polynuclear Aromatic Hydrocarbons,Aromatic Hydrocarbon, Polycyclic,Aromatic Hydrocarbon, Polynuclear,Aromatic Hydrocarbons, Polycyclic,Aromatic Hydrocarbons, Polynuclear,Aromatic Polycyclic Hydrocarbons,Hydrocarbon, Polycyclic Aromatic,Hydrocarbon, Polynuclear Aromatic,Hydrocarbons, Aromatic Polycyclic,Hydrocarbons, Polycyclic Aromatic,Hydrocarbons, Polynuclear Aromatic
D002412	Cations	Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.	Cation
D004734	Energy Metabolism	The chemical reactions involved in the production and utilization of various forms of energy in cells.	Bioenergetics,Energy Expenditure,Bioenergetic,Energy Expenditures,Energy Metabolisms,Expenditure, Energy,Expenditures, Energy,Metabolism, Energy,Metabolisms, Energy
D001256	Astronomy	The science concerned with celestial bodies and the observation and interpretation of the radiation received in the vicinity of the earth from the component parts of the universe (McGraw Hill Dictionary of Scientific and Technical Terms, 5th ed)
D055580	Astronomical Phenomena	Aggregates of matter in outer space, such as stars, planets, and comets; their properties; and the processes they undergo.	Astronomical Processes,Astronomic Concepts,Astronomic Phenomena,Astronomic Phenomenon,Astronomic Process,Astronomic Processes,Astronomical Concepts,Astronomical Process,Astrophysical Concepts,Astrophysical Phenomena,Astrophysical Phenomenon,Astrophysical Processes,Astronomic Concept,Astronomical Concept,Astrophysical Concept,Concept, Astronomic,Concept, Astronomical,Concept, Astrophysical,Concepts, Astronomic,Concepts, Astronomical,Concepts, Astrophysical,Phenomena, Astronomic,Phenomena, Astronomical,Phenomena, Astrophysical,Phenomenon, Astronomic,Phenomenon, Astrophysical,Process, Astronomic,Process, Astronomical,Processes, Astronomic,Processes, Astronomical,Processes, Astrophysical
D019443	Cosmic Dust	Finely divided solid matter with particle sizes smaller than a micrometeorite, thus with diameters much smaller than a millimeter, moving in interplanetary space. (NASA Thesaurus, 1994)	Interplanetary Dust,Interstellar Dust,Cosmic Dusts,Dust, Cosmic,Dust, Interplanetary,Dust, Interstellar,Dusts, Cosmic,Dusts, Interplanetary,Dusts, Interstellar,Interplanetary Dusts,Interstellar Dusts