Pyrene derivatives with two types of substituents at positions 1, 3, 6, and 8-fad or necessity?

Article abstract of DOI:10.1039/c9ra04503a

1,3,6,8-Tetrasubstituted pyrene derivatives with two types of substituents in an asymmetry or axial symmetry pattern have been prepared and characterized. To the best of our knowledge, these compounds are compared for the first time to their analogs containing the same substituent at all four positions, which explains the need for their synthesis. We present information on the chemistry of pyrenes, which are substituted in the non-K region, to help obtain the most efficient materials. Moreover, theoretical studies were extended to analogs which contain the first type of substituent at positions 1 and 3, whereas the second type of substituent is located at positions 6 and 8, for which the synthesis is nontrivial. The obtained data show which trend these kinds of molecules will follow.