Cyclotetrahalo-p-phenylenes: simulations of halogen substituted cycloparaphenylenes and their interaction with C₆₀

Abstract

Density functional calculations are used to study the role of edge-functionalization on the structure and electronic properties of cycloparaphenylene (CPPs) containing from six to twenty benzenoid rings. We substitute hydrogen by the halogens fluorine, chlorine and bromine. The resultant Cyclotetrahalo-p-phenylenes are compared with their hydrogenated equivalents, related linear paraphenyl and fluoro-paraphenyl polymers, and functionalised armchair edges in graphene nanoribbons. Notably we consider both structural and electronic evolution. Finally we examine C60@[10]CPP, i.e. C60 encapsulated within [10]CPP, with the various ring terminations. The effect of halogenation on electronic level position around the gap strongly affects their capacity to form donor-acceptor pairs with fullerenes.

Strain visualization for strained macrocycles

“…30 It is also possible to disassemble the molecule into an innite polymer and compare the repeating unit energies in both the macrocycle and the unstrained polymer. 31,32 If it were possible to connect these geometries by creating a trajectory between the strained and unstrained states, one could comment on how the energy of each atom changes to release strain energy as the trajectory proceeds. Ideally, the trajectory would begin in the optimized geometry of the strained molecule and descend to an unstrained innite polymer (Fig.…”

Nonlinear Optical Properties of the Hula Hoop [n]‐Cycloparaphenylenes and Their Halo Derivatives at Nd:YAG Laser Frequency

“…The first one is the even‐odd oscillations, which are very prominent for the chloride derivatives, and the second one is the increase in the optical gap as one increases the ring length. The trend observed are well in accordance with the works of Rio et al …”

Strain Visualization for Strained Macrocycles

“…It is also possible to disassemble the molecule into an infinite polymer and compare the repeating unit energies in both the macrocycle and the unstrained polymer. 29,30 If it were possible to connect the geometries by creating a trajectory between the strained and unstrained states, one could comment on how the energy of each atom changes to release strain energy as the trajectory proceeds. Ideally, the trajectory would begin in the optimized geometry of the strained molecule and descend to an unstrained infinite polymer (Figure 2a).…”