1. These calculations were performed using the programs implemented in SPARTAN from CA;Wavefunction;AM
2. cited therein q Pure Scheme Interior carbon atoms belong to three rings ; rim or edge carbon atoms can belong to either one ring methine or two rings quaternary but not three;Shabtai;Am Chem Soc Appl Chem,1998
3. These calculations were performed using the programs implemented in SPARTAN from CA;Wavefunction;AM