Shedding light on octathio[8]circulene and some of its plate-like derivatives

Abstract

A quantum chemical investigation is made on the recently synthesized octathio[8]circulene (C16S8), an exotic molecule, the first fully heterocyclic circulene, from the structural and electronic properties and some charge-transport parameters viewpoints. Since the molecule consists of eight thiophene rings fused together, we have chosen to compare it with the acyclic (octathienoacene) analogue and to some relatives thereof, in which the sulfur atoms are substituted by Se, NH, CH2 and O. C16S8, C16Se8 and C16S4Se4 are found to show a low reorganization energy comparable or lower than that for already well known field-effect transistor (FET) materials, a promising property which, combined to some others revealed by this study, makes these compounds potential candidates for FET use. In addition, the twist angle is found to be tightly linked to the peripheral bonds lengths, the least twisted structures showing the most interesting properties for organic FET use.

Impact of heterocirculene molecular symmetry upon two-dimensional crystallization

“…This feature is in contrast to the ‘circle with eight petals' appearance of 1 when it is trapped in the pores of a TMA network at the solution-graphite interface24. As each sulfur atom of 1 is chemically saturated in a five-member ring with significant aromaticity2627, the molecule-substrate interaction mainly derives from the coupling between the molecular π-electrons and the metal, akin to the planar polycyclic aromatic hydrocarbon molecules on Au(111) and in contrast to the strong S-Au bonding widely reported for thiols adsorbed on gold substrates34567891028293031. This molecule-substrate interaction is rather weak, as evidenced by frequent displacements of the molecules due to the disturbance exerted by STM tips during scanning with normal tunnelling parameters.…”

A rational design strategy for donors in organic solar cells: the conjugated planar molecules possessing anisotropic multibranches and intramolecular charge transfer

“…[20][21][22][23][24][25] The PBE1PBE 26,27 (also called PBE0) has been recognized to provide reliable predictions and interpretations of the molecular geometries, electronic properties, and optical properties of organic compounds bearing sulfur atoms. [28][29][30][31][32][33] To check the consistency of our calculation, preliminary density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were performed on BDT and the results were compared with available experimental data. Besides PBE0, the results of B3LYP [34][35][36] and B3P86 37 have also been compared with PBE0.…”

Theoretical Design of Benzoselenadiazole Based Organic Donor Molecules for Solar Cell Applications

“…It is found from earlier density functional theory (DFT) [59,60] investigations that the Perdew, Burke and Ernzerhof exchange-correlation functional (PBE0) [61,62] is efficient, and reliable in predicting properties of sulphur containing molecules [63][64][65][66][67][68]. Hence, the ground state geometries of all the molecules were optimized using the PBE0 functional with GenECP (6-31G (d,p) for C, N, O, S, H atoms and LANL2DZ [69][70][71] for Se atom) basis set.…”