1. jo;Spitler;Org Chem,2007
2. For the geometry optimization the method is considered to give satisfactory results for annulenes For the NICS calculations we employed the HF method as had been used in the original work of Schleyer because this method had been shown to be most reliable
3. jo a;Zhou;Org Chem,1294
4. anie For experimental proofs for the diradical character in derivatives of see;Kubo;Chem,2005