Suzuki, Masaaki Osuka, Atsuhiro Cross-Bridging Reaction of 5,20-Diethynyl Substituted Hexaphyrins to Vinylene-Bridged Hexaphyrins 5,20-Diethynyl substituted [26]hexaphyrins(1.1.1.1.1.1) undergo a thermal or spontaneous cross-bridging reaction to provide <i>trans</i>-vinylene-bridged [26]hexaphyrins, probably through strongly folded conformations. Facile aromatic−antiaromatic switching of vinylene-bridged hexaphyrins has been demonstrated upon two-electron redox processes. Curiously, a resonance contributor of the vinylene-bridged hexaphyrins is regarded as [16]diazaannuleno[16]diazaannulene but its contribution should be minor because of the perpendicular geometry of the bridge. Vinylene-bridged hexaphyrin serves as an effective ligand that coordinates two zinc(II) ions using the central vinylene double bond in a η<sup>2</sup>-fashion along with the three pyrrolic nitrogen atoms. resonance contributor;hexaphyrin;pyrrolic nitrogen atoms;Hexaphyrin 2007-01-24
    https://acs.figshare.com/articles/dataset/Cross_Bridging_Reaction_of_5_20_Diethynyl_Substituted_Hexaphyrins_to_Vinylene_Bridged_Hexaphyrins/3031426
10.1021/ja067102v.s001