Density Functional Calculations on the Molecular, Electronic Structures of Metal-Free, N,N'-Dideuterio and Magnesium Tetra-3,4-Pyridino-Porphyrazines

Abstract

A theoretical calculation of the fully optimized geometries and electronic structures of the metal-free Tetra-2,3-Pyridino-Porphyrazine (TPdPzH2*), N,N-Dideuterio (TPdPzD2*), and Magnesium (TPdPzMg*) tetra-3,4-pyridino-porphyrazine has been conducted with the density functional B3LYP level using the 6-31G(d) basis set. A comparison among the different Phthalocyanine (Pc) derivatives, including Tetra-2,3-Pyridino-Porphyrazine (TPdPzH2) compounds, for the geometry, molecular orbital, and atomic charge was made. The substitution effect of the N atoms and the isotopic effect of D atoms on the properties of these compounds were discussed. The farther the heterocyclic N atoms in the benzo rings from 16-membered ring are, the smaller it influence the size of the central hole, the bond lengths and bond angles of 16-membered ring, the HOMO-LUMO gaps, and the atomic charges on the core Pz fragment. In other words, the properties of TPdPz* compounds are closer to Pc than TPdPz. With the order of H2Pc<TPdPzH2<TPdPzH2*, the acidity of the inner N-H bonds in the three molecules increased in turn.