Gas phase synthesis of the C40 nano bowl C40H10

Abstract

Nanobowls represent vital molecular building blocks of end-capped nanotubes and fullerenes detected in combustion systems and in deep space such as toward the planetary nebula TC-1, but their fundamental formation mechanisms have remained elusive. By merging molecular beam experiments with electronic structure calculations, we reveal a complex chain of reactions initiated through the gas-phase preparation of benzocorannulene (C24H12) via ring annulation of the corannulenyl radical (C20H9•) by vinylacetylene (C4H4) as identified isomer-selectively in situ via photoionization efficiency curves and photoion mass-selected threshold photoelectron spectra. In silico studies provided compelling evidence that the benzannulation mechanism can be expanded to pentabenzocorannulene (C40H20) followed by successive cyclodehydrogenation to the C40 nanobowl (C40H10) – a fundamental building block of buckminsterfullerene (C60). This high-temperature pathway opens up isomer-selective routes to nanobowls via resonantly stabilized free-radical intermediates and ring annulation in circumstellar envelopes of carbon stars and planetary nebulae as their descendants eventually altering our insights of the complex chemistry of carbon in our Galaxy.

Gas-Phase Synthesis of Coronene through Stepwise Directed Ring Annulation

“…The exploitation of PIE curves and ms-TPE spectra in tandem enables isomer-selective identification of hydrocarbon molecules (Supporting Information, Figures S7 and S8). − …”

Role of Acetylene in the Chemical Evolution of Carbon Complexity

“…Recently, Tuli et al 412 suggested a new "bottom-up" pathway to form a building block of fullerenes�a nanobowl C 40 H 10 . The nanobowl can be obtained through a chain of reactions starting from the corannulene molecule, whose formation was described above in Section 5.2.3.…”

Gas-phase C60Hn+q (n = 0–4, q = 0,1) fullerenes and fulleranes: spectroscopic simulations shed light on cosmic molecular structures

“…Additionally, several efforts on synthesis and characterization were done focused on C 60 H 2 and C 60 H 4 fulleranes. 24–30 Furthermore, a recent successful and facile bottom-up synthesis of C 40 H 10 from benzocorannulene, a structural isomer of coronene, 31 further emphasizes the significance of fulleranes in the astrochemical context.…”