Side-Chain Type Ferrocene Macrocycles

A class of side-chain type ferrocene macrocycles with a radially conjugated system is introduced in this study. The stereo configurations of these ferrocene rings were determined through single-crystal X-ray diffraction analysis. Notably, in the solid state, the ferrocene rings exhibit a distinctive herringbone stacking pattern imposed by a ferrocene-to-ring host–guest interaction. Through UV–vis absorption spectroscopy, electrochemical measurements, and theoretical calculations, valuable insights into the electronic properties of these rings were obtained. In addition, the single crystal of macrocycle A2B demonstrates a second-order nonlinear optical response. As a class of organometallic nanorings, this work holds great potential for further exploration in the fields of organometallic chemistry, molecular electronics, and host–guest chemistry.