title: CNDO molecular orbital calculations on porphyrins--II. Ground states of dilithium and disodium porphyrin.
abstract: CNDO/2 calculations are reported for dilithium and disodium porphyrin. The total energy is calculated as a function of the metal-ring distance for symmetrical (D4h) structures. For dilithium porphyrin, the equilibrium metal-ring distance is 0.87 A and the metal-metal vibrational frequency is 123 cm-1. For disodium porphyrin, the distance is 1.64 A and the frequency is 77 cm -1. Little mixing of metal and porphyrin orbitals takes place; the two lowest unoccupied and the two highest occupied MOs hardly differ from those in porphyrin, but lower MOs are considerably rearranged.
mesh_terms: D008094:Lithium; D008968:Molecular Conformation; D011166:Porphyrins; D012964:Sodium; D013057:Spectrum Analysis
chemical_list: D011166:Porphyrins; D008094:Lithium; D012964:Sodium