Formation of Slipped Dimer in 6‐Pentafluorophenyl‐substituted Olympicenyl Radical

Abstract

Comprehensive SummaryIntroduction of substituents to organic radical is important to increase the stability and realize its applications as multifunctional materials. In this work, pentafluorophenyl group was introduced to 6‐position of olympicenyl radical (OR) via a newly designed synthetic strategy to afford the fourth OR derivative, OR4. Due to the combined electro‐withdrawing effect and steric hindrance of pentafluorophenyl, OR4 was stable and isolable in crystalline state. A slipped dimer was found in single crystal structure dominated by C—H···F interaction. SQUID measurements revealed a singlet–triplet energy gap of −0.47 kcal·mol−1 for the slipped dimer, suggesting weak SOMO–SOMO interaction. Moreover, electro‐withdrawing effect of pentafluorophenyl leads to a positive shift (0.15 V) of oxidative wave for OR4 compared with 6‐triisopropylsilylethynyl protected OR derivatives.