Fig. 3. Top view and side view of the X-ray crystallographic structure of (a) compound 9 (precursor for PH 1) and (b) tetraradicaloid 2; the hydrogen atoms are omitted for clarity. Selected bond lengths (Å) and calculated NICS(1)av values in the rings A-I of (c) 1 and (d) 2. Calculated ACID plots of (e) 1 and (f) 2. Isovalue is 0.05, and the blue and red arrows indicate diamagnetic and paramagnetic ring current flows, respectively.
