Effect of Imide Functionalization on the Electronic, Optical, and Charge Transport Properties of Coronene: A Theoretical Study

Abstract

We investigate the energetics, electronic structure, optical properties, and charge transfer characteristics of coronene and its imide-functionalized derivatives using quantum chemical calculations. We analyze the formation feasibility of pristine coronene and its different imide monomers, namely, coronene-5-diimide, coronene-6-diimide, and coronene-tetraimide, from a common parental compound, coronene octacarboxylic acid, and find that the most favorable derivative is the pure coronene. Our results also show that coronene-6-diimide is preferred over other possible imide compounds, which is well in accordance with the relative experimental abundance of coronene-6-diimide. The absorption characteristics obtained for both the monomer and dimer of coronene imides show bathochromic shifts for the low-energy peak positions in comparison to the pristine coronene because of the presence of the electron withdrawing imide groups, and the trend in transition energy follows the order of the electronic gap. Interestingly, we find a larger extent of red shift for the absorption maxima of the synthetically more feasible coronene-6-diimide among others. Moreover, our analysis also shows that the extent of red shift strongly depends on the position and orientations of the imide groups, and the low-energy peaks solely correspond to the π–π* electronic transitions. Furthermore, we also calculate the charge (electron and hole) transfer integrals for the plausible stable dimers, and find that effective hole transfer integrals are significantly larger than the electron transfer integral except for the coronene-tetraimide, for which the electron transfer integral is found to be greater than the hole transfer integral. The calculated carrier mobilities for the coronene crystal show that the hole mobility is significantly larger, almost 15 times, than the electron mobility. Our study provides a detailed understanding of the tunable optical and charge transfer properties for imide-functionalized coronene derivatives, and suggests their potential use in optoelectronic and field effect transistor devices.

Theoretical study of stability and charge-transport properties of coronene molecule and some of its halogenated derivatives: A path to ambipolar organic-based materials?

“…In the case of coronene, these values are larger for hole than for electron transport (206 vs 101 meV, respectively), close to previously reported results of 167 and 65 meV obtained in Ref. 72 with the PBE/TZVP method and at the ωB97XD 98 optimized geometry of the dimer. We have also checked the results for electronic couplings at the corresponding crystal geometry of the dimer: our values for hole and for electron transport (161 vs 86 meV, respectively) still hold the trend found before.…”

“…For the coronene case, we calculate rather similar values for both e ·− (144 meV) and h ·+ (189 meV), giving a ratio h ·+ / e ·− equal to 0.76 and thus close to ambipolar behavior, remaining the same other features. Note also that: (i) previous estimates of reorganization energies for coronene at the B3LYP/6-311++G(d,p) level agrees within 10% or our values; 72 and (ii) the use of a more sophisticated although more costly functional (the double-hybrid B2π -PLYP model, specially devised for accurately dealing with π -conjugated systems of any type 73 ) only slightly change the absolute values of e ·− and h ·+ , being now of 128 and 162 meV, respectively, still keeping a similar ratio (0.79). We also observe that upon halogenation, both h ·+ or e ·− increase, as it was also observed before for partially substituted tetracene molecules 74 or for larger phthalocyanine systems, 75 although the ratio h ·+ / e ·− is not largely affected, being always within the 0.7-1.0 range of values and thus favouring an ambipolar transport (once and again, if all other factors remain the same).…”

Determining the cohesive energy of coronene by dispersion-corrected DFT methods: Periodic boundary conditions vs. molecular pairs

“…We would like to emphasize how this energy gain is known to govern many interesting electronic properties of coronene samples, such as the anisotropic charge mobility values in organic electronic devices 93,94 or the thermochemistry of their spontaneous self-aggregation. 95,96 We can also see from Tables II and III that the interaction energy of the (0,b,0) dimer ranges from −68 kJ/mol (B3LYP-D3/def2-QZVP) to −98 kJ/mol (B2-PLYP-NL/def2-TZVP).…”

Trends in molecular design strategies for ambient stable n-channel organic field effect transistors

“…With the exception of the tetradiimide, charge transfer integrals are larger for holes than for electrons and the electron mobilities were found to be 15 times smaller than the hole mobilities. 187 However, some charge transfer integrals for holes are larger than the reorganization energies, which means that hole transport is overestimated by using Marcus theory in these systems. 43 …”