Topological Ring Currents in Open-Shell Homologues of Clar’s Goblet and Triangulene

The Hückel-London-Pople-McWeeny (HLPM) formalism for calculating "topological" ring currents was recently extended to make it applicable to open-shell π-electron-conjugated systems. This modification, which incorporates the device of "Configurational State Averaging" (also known as "Electron Smearing" and "Fractional Occupation"), was then used to calculate the topological ring currents associated with the 11-ring benzenoid diradical that has become known as Clar's goblet. The present paper investigates the quantitative trends among the topological ring currents in some other classic diradicals, and other multiple radicals, that are now accessible via the HLPM approach, namely, certain homologues of Clar's goblet and triangulene and several of their oxidation states, and compares their patterns and sizes with pictorial current maps generated by more sophisticated pseudo-π and <i>ab initio</i> calculations.