Fig. 4. Optimized structures, together with the key bond lengths (blue values) in angstroms. The blue values in Pyr2– , Pyr, and C6H6 2– are the bond lengths of the pyrrole ring in IM4, IM4T , and Ti(OMe)2–C6H6 , respectively. NICS(1) is the NICS value (in ppm) at a point 1.0 Å above the ring center, respectively. The red italic values are WBIs and WBIsum is the sum of the individual WBIs.
