Perspective: C60+ and laboratory spectroscopy related to diffuse interstellar
          bands

Campbell, E. K.; Maier, John P.

doi:10.1063/1.4980119

Cited by 29 publications

(21 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The interest of long carbon chains as DIB carriers has been emphasised for more than 40 years (Douglas 1977, Thaddeus 1995, and especially John Maier's Basel group, e.g. Rice & Maier 1993;Fischer & Maier 1997;Zack & Maier 2014a,b;Campbell & Maier 2017). It is generally agreed, however, that chains with N C < ∼ 15 are excluded based on laboratory results (e.g.…”

Section: Carbon Chainsmentioning

confidence: 99%

Correlation between UV resilience and wavelength of narrow diffuse interstellar bands

Omont

Bettinger

2020

A&A

View full text Add to dashboard Cite

Carriers of diffuse interstellar bands (DIBs) still need to be identified. In a recent paper, we reported a correlation between the DIB wavelength and the apparent UV resilience (or boost) of their carriers. We proposed that this might be an indication of the important role of conjugated elongated molecules among the DIB carriers. The aim of this paper is to further understand the origin of this correlation. The analysis of 509 optical DIBs on the lines of sight of HD 183143 and/or HD 204827 reported in the literature shows that this correlation mainly implies the 386 narrow DIBs with a band width < 1.1 Å, which include most of the identified DIBs of the C2 and ζ families, while the majority of the 123 broader DIBs, including the identified σ DIBs, do not display such a correlation. We present a possible origin of this correlation from very strong bands of large conjugated elongated molecules, such as carbon chains, polyacenes, or other catacondensed polycyclic aromatic hydrocarbons. The total amount of carbon contained in all the carriers of these narrow DIBs is a very small fraction of the interstellar carbon if their oscillator strengths are ≥ 1. The amount of carbon locked in the carriers of the broader DIBs is higher, especially if their oscillator strengths are significantly weaker.

show abstract

Section: Carbon Chainsmentioning

confidence: 99%

Correlation between UV resilience and wavelength of narrow diffuse interstellar bands

Omont

Bettinger

2020

A&A

View full text Add to dashboard Cite

show abstract

“…Due to its versatility, C 60 is still a matter of numerous current studies, including diffuse intrastellar bands as well. One of its versatility is inferred from the propensity to confine a “guest” atom or molecule within its hollow cage, or void, that has been confirmed within a week after the discovery of C 60 by synthesizing the so called lanthanium endofullerene, La@C 60 , where “at,” @, means that the La atom is trapped inside C 60 .…”

Section: Introductionmentioning

confidence: 99%

On the Existence of HeHe Bond in the Endohedral Fullerene Hе₂@C₆₀

2017

View full text Add to dashboard Cite

Twenty years have already been passed since the endohedral fullerene's void ceaselessly attracts attention of both, experimentalists and theoreticians, computational chemists and physicists in particular, who direct their efforts on computer simulations of encapsulating atoms and molecules into fullerene void and on unraveling the arising bonding patterns. We review recent developments on the endohedral He @C fullerene, on its experimental observation and on related computational works. The two latter are the main concerns in the present work: on the one hand, there experimentally exists the He dimer embedded into C void. On the other, computational side, each He atom exhibits a negligible charge transfer to C resulting in that altogether, the He dimer exists as a fractionally charged (He ) . Whether there exists a bond between these two helium atoms is the key question of the present work. Since a bond is a two-body creature, we assert that it suffices to define the bond on the basis of Löwdin's postulate of a molecule which we invoke to investigate such formation of the He dimer in a given C void in terms of the HeHe potential energy well. It is analytically demonstrated that this well enables to maintain at least one bound (ground) state, and therefore, according to Löwdin's postulate which is naturally anticipated within quantum theory, we infer that (He ) is a molecule, a diatomic, where two heliums are bonded to each other. Using these arguments, we also propose to extend the concept of stability of endohedral fullerenes. © 2017 Wiley Periodicals, Inc.

show abstract

“…It might be very small if dehydrogenated PAHs were mainly photodissociated through successive C 2 ejections (or formed nanotubes). Nevertheless, if they form efficiently from dehydrogenated PAHs, some of these fullerenes might have an abundance comparable to or greater than C + 60 , whose abundance in the diffuse ISM may be roughly estimated as ∼2 ×10 −4 from its DIB strength (Walker et al 2015;Campbell & Maier 2017;Omont 2016). Large abundances like this, if confirmed, should A193, page 4 of 13 A. Omont and H. F. Bettinger: Intermediate-size fullerenes make some fullerenes smaller than C 60 detectable through their IR emission bands or their visible absorption bands (DIBs), as we discuss in the next section.…”

Section: Fullerene Sputtering and Possible Abundancesmentioning

confidence: 99%

Intermediate-size fullerenes as degradation products of interstellar polycyclic aromatic hydrocarbons

Omont

Bettinger

2021

A&A

View full text Add to dashboard Cite

The high interstellar abundances of polycyclic aromatic hydrocarbons (PAHs) and their size distribution are the result of complex chemical processes implying dust, UV radiation, and the main gaseous components (H, C+, and O). These processes must explain the high abundance of relatively small PAHs in the diffuse interstellar medium (ISM) and imply the continuous formation of some PAHs that are small enough (number of carbon atoms NC < ~35–50) to be completely dehydrogenated by interstellar UV radiation. The carbon clusters Cn thus formed are constantly exposed to the absorption of ~10–13.6 eV UV photons, allowing isomerization and favoring the formation of the most stable isomers. They might tend to form irregular carbon cages. The frequent accretion of interstellar C+ ions could favor further cage isomerization, as is known in the laboratory for C60, possibly yielding most stable fullerenes, such as C40, C44, and C50. These fullerenes are expected to be very stable in the diffuse ISM because C2 ejection is not possible by single UV photon absorption, but could need rare two-photon absorption. It is possible that at least one of these fullerenes or its cation is as abundant as C60 or C60+ in the diffuse ISM, although this abundance is limited by the lack of observed matching features in observed mid-infrared spectra. B3LYP calculations of the visible spectrum for a number of fullerene isomers with 40 ≤NC ≤ 50 show that they generally have a few spectral bands in the visible range, with f-values in the range of a few 10−2. This could make such fullerenes interesting candidates for the carriers of some diffuse interstellar bands.

show abstract

Perspective: C60+ and laboratory spectroscopy related to diffuse interstellar bands

Cited by 29 publications

References 75 publications

Correlation between UV resilience and wavelength of narrow diffuse interstellar bands

Correlation between UV resilience and wavelength of narrow diffuse interstellar bands

On the Existence of HeHe Bond in the Endohedral Fullerene Hе₂@C₆₀

Intermediate-size fullerenes as degradation products of interstellar polycyclic aromatic hydrocarbons

Contact Info

Product

Resources

About

Perspective: C60+ and laboratory spectroscopy related to diffuse interstellar bands

Cited by 29 publications

References 75 publications

Correlation between UV resilience and wavelength of narrow diffuse interstellar bands

Correlation between UV resilience and wavelength of narrow diffuse interstellar bands

On the Existence of HeHe Bond in the Endohedral Fullerene Hе2@C60

Intermediate-size fullerenes as degradation products of interstellar polycyclic aromatic hydrocarbons

Contact Info

Product

Resources

About

On the Existence of HeHe Bond in the Endohedral Fullerene Hе₂@C₆₀