English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The first gas-phase infrared spectra of two isolated astronomically relevantand large PAH cations - diindenoperylene (DIP) and dicoronylene (DC) - in the530$-$1800 cm$^{-1}$ (18.9$-$5.6 $\mu$m) range - are presented. Vibrationalband positions are determined for comparison to the aromatic infrared bands(AIBs). The spectra are obtained via infrared multiphoton dissociation (IRMPD)spectroscopy of ions stored in a quadrupole ion trap (QIT) using the intenseand tunable radiation of the free electron laser for infrared experiments(FELIX). DIP$^{+}$ shows its main absorption peaks at 737 (13.57), 800 (12.50),1001 (9.99), 1070 (9.35), 1115 (8.97), 1152 (8.68), 1278 (7.83), 1420 (7.04)and 1550 (6.45) cm$^{-1}$($\mu$m), in good agreement with DFT calculations thatare uniformly scaled to take anharmonicities into account. DC$^+$ has its mainabsorption peaks at 853 (11.72), 876 (11.42), 1032 (9.69), 1168 (8.56), 1300(7.69), 1427 (7.01) and 1566 (6.39) cm$^{-1}$($\mu$m), that also agree wellwith the scaled DFT results presented here.  The DIP$^+$ and DC$^+$ spectra are compared with the prominent infraredfeatures observed towards NGC 7023. This results both in matches and cleardeviations. Moreover, in the 11.0$-$14.0 $\mu$m region, specific bands can belinked to CH out-of-plane (oop) bending modes of different CH edge structuresin large PAHs. The molecular origin of these findings and their astronomicalrelevance are discussed.

astrophysical journal/the astrophysical journal

Laboratory gas-phase infrared spectra of two astronomically relevant PAH  cations: diindenoperylene, C$_{32}$H$_{16}$$^+$ and dicoronylene,  C$_{48}$H$_{20}$$^+$