Stable and abundant spin-1/2 species from azafullerene (C59N˙) supramolecularly hosted in [10]cycloparaphenylene nanohoops are operated as stable qubits, with possibility of qubit wiring via intermediate polymerized spin-redistributed states.

We successfully functionalized MoS2 and WS2 with Zn-porphyrin through 1,2-dithiolane addition. This creates mixed 0–2 dimensional materials since porphyrins are discrete on the basal plane of TMDs. This localization results in a new emission band with a 3.5 ns lifetime at 77.5 K with an excitation power of 17 W/cm2 in the near-infrared (NIR) region (1.40–1.51 eV), which originates from charge-separated states between ZnP and WS2. The optical response of excitonic species, including trion, biexcitons, and excitons, is substantially enhanced at the porphyrin absorption region, supporting electron transfer between ZnP and WS2. Sensing time-response improves after functionalization, suggesting that electrons injected from ZnP to TMDs contribute to filling trap states. Incorporating ZnP also enhances the stability of WS2 and MoS2 against atmospheric photodegradation. Theoretical modeling supports these findings, suggesting an intimate relationship between orbitals in the ground and excited states of porphyrin and TMDs.

Hydrogenated small fullerenes (Cn, n < 60) are of interest as potential astrochemical species, and as intermediates in hydrogen-catalysed fullerene growth. However, the computational identification of key stable species is difficult due to the vast configurationally space of structures. In this study, we explored routes to predict stable hydrogenated small fullerenes. We showed that neither local fullerene geometry nor local electronic structure analysis was able to correctly predict subsequent low-energy hydrogenation sites, and sequential stable addition searches also sometimes failed to identify most stable hydrogenated fullerene isomers. Of the empirical and semi-empirical methods tested, GFN2-xTB consistently gave highly accurate energy correlations (r > 0.99) to full DFT-LDA calculations at a fraction of the computational cost. This allowed identification of the most stable hydrogenated fullerenes up to 4H for four fullerenes, namely two isomers of C28 and C40, via “brute force” systematic testing of all symmetry-inequivalent combinations. The approach shows promise for wider systematic studies of smaller hydrogenated fullerenes.

Using laser-induced vaporisation to evaporate and ionise a source of curved polyaromatic hydrocarbons (carbon nanobelts), we show collision impacts between species cause mass loss and the resultant ions are catalogued via mass-spectrometry. These data are interpreted via a series of “in-silico”-simulated systematic hydrogen-loss studies using density functional theory modelling, sequentially removing hydrogen atoms using thermodynamic stability as a selection for subsequent dehydrogenation. Initial hydrogen loss results in the formation of carbyne chains and pentagon-chains while the nanobelt rings are maintained, giving rise to new circular strained dehydrobenzoannulene species. The chains subsequently break, releasing CH and C2. Alternative routes towards the formation of closed-cages (fullerenes) are identified but shown to be less stable than chain formation, and are not observed experimentally. The results provide important information on collision degradation routes of curved molecular carbon species, and notably serve as a useful guide to high-energy impact conditions observed in some astrochemical environments.

We investigate the effect of introducing C60 to (C59N)2 and the molecular ring, [10]cycloparaphenylene ([10]CPP), using electron paramagnetic resonance (EPR) measurements supported by density functional theory (DFT) calculations. Incorporating C60 into the system results in the formation of novel stable [10]CPP ⊃ C59N-C60 • ⊂ [10]CPP encapsulated heterodimer radicals whose spin is localized on C60 and manifests in EPR measurements as a signal at g = 2.0022 without any discernable hyperfine structure. This signal has an exceptionally long spin coherence lifetime of 440 μs at room temperature, far longer than any of the radical fullerene species reported in the literature and over twice that of the C59N• ⊂ [10]CPP radical. The radicals are long-lived, with EPR signal still strong over a year after thermal activation. The [10]CPP ⊃ C59N-C60 • ⊂ [10]CPP oligomer is more stable than C59N• ⊂ [10]CPP radicals and becomes the predominant species at room temperature after annealing. Its formation is thermally activated with an experimental activation energy of only 0.189 eV, as compared to 0.485 eV for the pure azafullerene-[10]CPP case. The [10]CPP ⊃ C59N-C60 • ⊂ [10]CPP radicals discovered here could be used to bridge C59N• ⊂ [10]CPPs acting as qubits, providing effective coupling between them.

Hydrogenated small fullerenes (Cn, n&lt;60) are of interest as potential astrochemical species, and as intermediates in hydrogen catalysed fullerene growth. However computational identification of key stable species is difficult due to the vast combinatorial space of structures. In this study we explore routes to predict stable hydrogenated small fullerenes. We show that neither local fullerene geometry nor local electronic structure analysis are able to correctly predict subsequent low energy hydrogenation sites, and indeed sequential stable addition searches also sometimes fail to identify most stable hydrogenated fullerene isomers. Of the empirical and semi-empirical methods tested, GFN2-xTB consistently gives highly accurate energy correlation (r&gt;0.99) to full DFT-LDA calculations at a fraction of the computational cost. This allows identification of the most stable hydrogenated fullerenes up to 4H for four fullerenes, namely two isomers of C28 and C40, via &ldquo;brute force&rdquo; systematic testing of all symmetry inequivalent combinations. The approach shows promise for wider systematic studies of smaller hydrogenated fullerenes.

We explore the importance of curvature in carbonaceaous species transformation and stability, using laser-induced vaporisation to evaporate and ionise a source of curved polyaromatic hydrocarbons: carbon nanobelts. Collision impacts between species cause mass loss and the resultant ions are catalogued via mass-spectrometry. To interpret the mass spectra, we perform a series of &ldquo;in-silico&rdquo; simulated systematic hydrogen-loss studies using density functional theory (DFT) modelling, sequentially removing hydrogen atoms using thermodynamic stability as a selection for subsequent dehydrogenation. In an initial sequence of H2 removal, the rings are maintained through stable carbyne chain and pentagon-chain formation, giving rise to circular strained dehydrobenzoannulene species. The chains subsequently break, releasing CH and C2. While theoretical closed-cage routes are identified, they are not observed experimentally. The results can serve as a useful guide to high-energy impact conditions observed in some astrochemical environments.

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