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

The present study aims to establish the role of halogen substituents in tuning the nonlinear optical (NLO) properties of cycloparaphenylenes. We employed time dependent density functional theory as our prime investigating tool to estimate the frequency dependent components of first order hyperpolarizability tensors of these systems at neodymium‐doped yttrium aluminium garnet (Nd:YAG) laser frequency. Our results indicate that pristine cycloparaphenylenes have high nonlinear optical properties which corroborates well with reported experimental findings and one can increase this nonlinearity by adding halogen to these species and tuning them as well. This tuning is of great significance as this will allow us to design and synthesize new compounds which have the strong potential to act as NLO materials. Our results also show functional dependence for the NLO tensor components while calculating the NLO properties for molecular systems. The basis set and the solvent effects, however, is not appreciable for the cycloparaphenylenes.