scholarly journals Heptagon-Containing Saddle-Shaped Nanographenes: Self-Association and Complexation Studies with Polycyclic Aromatic Hydrocarbons and Fullerenes

2021 ◽  
Vol 03 (01) ◽  
pp. 051-059
Author(s):  
Arthur H. G. David ◽  
Sandra Míguez-Lago ◽  
Carlos M. Cruz ◽  
Juan M. Cuerva ◽  
Victor Blanco ◽  
...  

Supramolecular interactions between molecules of the same or different nature determine to a great extent the degree of their applicability in many fields of science. To this regard, planar polycyclic aromatic hydrocarbons (PAHs) and their nanometric congeners, nanographenes (NGs), as well as positively curved ones, as for instance corannulene, have been extensively explored. However, negatively curved saddle-shaped NGs have remained a curiosity to date within this field. Therefore, here we communicate the first systematic study on the supramolecular behavior of heptagon-containing hexa-peri-hexabenzocoronene analogues. Thus, their self-association and host–guest complexation processes with both flat and curved PAHs, and fullerenes have been studied by means of 1H and 13C NMR titrations in solution, identifying C70 as one of the guests with the highest association constant among all the ones tested.

2021 ◽  
Author(s):  
Réka Mokrai ◽  
Rózsa Szűcs ◽  
Matthew P. Duffy ◽  
Vincent Dorcet ◽  
Thierry Roisnel ◽  
...  

Topologically divers PAHs with planar, twisted and negatively curved topologies were obtained from polycyclic phospholes using pericyclic reactions.


2019 ◽  
Vol 64 (1) ◽  
pp. 55-67
Author(s):  
Vlad Pӑnescu ◽  
◽  
Mihaela Cӑtӑlina Herghelegiu ◽  
Sorin Pop ◽  
Mircea Anton ◽  
...  

2019 ◽  
Author(s):  
Yachu Du ◽  
Kyle Plunkett

We show that polycyclic aromatic hydrocarbon (PAH) chromophores that are linked between two five-membered rings can access planarized structures with reduced optical gaps and redox potentials. Two aceanthrylene chromophores were connected into dimer model systems with the chromophores either projected outward (2,2’-biaceanthrylene) or inward (1,1’-biaceanthrylene) and the optical and electronic properties were compared. Only the planar 2,2’-biaceanthrylene system showed significant reductions of the optical gaps (1 eV) and redox potentials in relation to the aceanthrylene monomer.<br>


2019 ◽  
Author(s):  
Yachu Du ◽  
Kyle Plunkett

We show that polycyclic aromatic hydrocarbon (PAH) chromophores that are linked between two five-membered rings can access planarized structures with reduced optical gaps and redox potentials. Two aceanthrylene chromophores were connected into dimer model systems with the chromophores either projected outward (2,2’-biaceanthrylene) or inward (1,1’-biaceanthrylene) and the optical and electronic properties were compared. Only the planar 2,2’-biaceanthrylene system showed significant reductions of the optical gaps (1 eV) and redox potentials in relation to the aceanthrylene monomer.<br>


Author(s):  
M. Assad ◽  
V. V. Grushevski ◽  
O. G. Penyazkov ◽  
I. N. Tarasenko

The concentration of 16 polycyclic aromatic hydrocarbons (PAHs) in the gasoline combustion products emitted into the atmosphere by internal combustion engines (ICE) has been measured using the gas chromatography method. The concentrations of PAHs in the exhaust gases sampled behind a catalytic converter has been determined when the ICE operates in five modes: idle mode, high speed mode, load mode, ICE cold start mode (engine warm-up) and transient mode. Using 92 RON, 95 RON and 98 RON gasoline the effect of the octane number of gasoline on the PAHs content in the exhaust gases has been revealed. The concentration of the most carcinogenic component (benzo(α)pyrene) in the exhaust gases behind a catalytic converter significantly exceeds a reference value of benzo(α)pyrene in the atmospheric air established by the WHO and the EU for ICE in the load mode.


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