Intermacrocyclic Interactions upon Stepwise Oxidations in a Monometallic Porphyrin Dimer: Ring versus Metal‐Center Oxidations and Effect of Counter Anions

Abstract

The effect of intermacrocyclic interactions was studiedb ycontrolled and stepwise oxidations of amonometallic silver(II) porphyrind imer that contains ah ighly flexible ethane bridge.M onometallic dimers are uniques ystems and behaved ifferently from their dimetallic analogues on the basis of their availables ites for storing oxidizing equivalents. UV-visible spectrometry, 1 HNMR spectroscopy,X PS and single crystal X-ray diffraction studies clearly suggestt he removal of the first electron from the metal center. The removal of the second electron occurred from the ring center to form a p-cation radical and, thereby, form av ery unique mixed-valent species.H owever,u nlike in all other ethanebridged metalloporphyrin dimers reported earlier,t he 2e-oxidized speciess howed quite unusual structures depending on the natureo fc ounter ions. Ions, such as SbF 6 ,S bCl 6 and PF 6 ,a re engaged in strong interactions with the porphyrin p-cationr adical and causes substantial structuralc hanges, including large deformation of the ring. The solid-state structure remains intact in solutiona swell. The observations are further supported by DFT calculations.