New Concepts II

Acta adjacency matrix annulene antarafacial antibonding approach approximation aziridine basis set bipartite graph bond orders butadiene C₁ calculations carbon Chem chemical chemistry Chim CNDO coefficients compounds configuration conjugated molecules conrotatory conrotatory motion Correlation diagram corresponding Coulson cyclobutane cyclopropane Dewar dipole disrotatory eigenvalues electrocyclic reactions electron electrophilic electrostatic potential ethylene example expansion experimental Gaussian geometry graph G graph spectrum Graph Theory Gutman H H H Hückel rule hydrocarbons interaction kcal/mole Kekulé structures Khim linear lone pair Longuet-Higgins method minima MO theory molecular orbitals molecular topology molecule NAHS obtained orbital symmetry photochemically Phys Pople potential surface Potential-energy map prediction problem proton quantum reactants reaction path reactivity ring plane Sachs graphs Sachs theorem Salem shown in Fig sigmatropic reactions Simonetta singlet suprafacial symmetry plane symmetry rules Tetrahedron theoretical thermally allowed tion topological transition Trinajstić values vertex vertices wave functions zero