The DFT Study On The Structures And Properties Of Heterocyclic Phthalocyanine And Heterocyclic Naphthalocyanine Compounds

Phthalocyanine is a kind of microcycle compound withлconjugated system. A significant characteristic of phthalocyanine is the versatility and tailoring properties, some chemical modification on the molecular structure of phthalocyanine can well adjust its performance, including the change of the central metal,the introduce of substituents on the phthalocyanine outer rings as well as replacing the benzene rings with heterocycles to generate heterocyclic phthalocyanine compounds. Such modification can gain many kinds of phthalocyanine compounds with special properties and functions.1,The DFT study of heterocyclic phthalocyanine compoundsA detailed depiction of the geometrical structures, molecular orbitals, atomic charges, UV-Vis spectra and IR spectra of tetrathieno[2,3-b]porphyrazine(TTPPzH2), along with its magnesium complexes(TTPPzMg) have been performed on the basis of DFT and TD-DFT calculation at the B3LYP/6-31G(d) level.The geometrical structures of the central Pz fragment for TTPPzH2 and TTPPzMg, including bond lengths, bond angles and central hole size are changed owing to the substituented effect of thiophene heterocycles. It is worth noting that the substituented effect of thiophene heterocycles does not have significant effect on the charge contribution except for Cβatoms, which are adjacent to the sulfur atoms in the protonated or deprotonated pyrrole rings.The substituented effect of thiophene heterocycles not only changes the molecular orbitals, including energy level and symmetry, but also leads to a blue shift of the Q band in a certain extent, making the HOMO-LUMO gap grow wider; At the same time, it lowers the stabilization of the lower lying occupied orbitals, making a red shift of the B band. With the assistance of animated pictures produced on the basis of the normal coordinates, the vibration modes in the IR spectra of all the compounds were also identified, which is in accordance well with other related calculations and the experimental results. This shows that this method for studying this kind macromolecular compounds is very fit.2,The DFT study of heterocyclic naphthalocyanine compoundsA detailed depiction of the geometrical structures, molecular orbitals, atomic charges, UV-Vis spectra and IR spectra of octaaza-naphthalocyanine germanium(OANcGe),octaaza-naphthalocyanine tin(OANcSn) and octaaza-naphthalocyanine lead(OANcPb) have been performed on the basis of DFT and TD-DFT calculation at the B3LYP/LANL2DZ level.This result shows that the difference in geometrical structures of the three metal c- omplexes is mainly manifested in the different spacing between the central metal ions and the neighboring Nc atoms, the influence of the central metal ion to the molecular structure decreases with the disdance of Nc atoms leaving the central metal ion. Meanwhile, as the enhancement of the golden attribute from Ge to Pb, the positive charge on the central metal atom increases.The HOMO-LUMO gaps of the three metal complexes enlarge with the enlargement of the metal ion radiu, following the order of OANcGe<OANcSn<OANcPb, in the meantime, each orbital energy level of the three metal complexes lowers along with the enlargement of the central metal ion radiu, following the order of OANcGe>OANcSn>OANcPb. It needs to be emphasized that although orbital energy levels differ a lot, while the orbital symmetry is the same. It indicates that the influence of the change of the metal ion radiu to the orbital energy level is more than that to the orbital symmetry.Though comparing the main electronic transitions of the three metal complexes, the metal ion radiu goes into the center caity with more difficult as the enlargement of the metal ion radiu, it is not in the plane of ring, thus, lowering the key role between the metal and octaaza-naphthalocyanine ring and making the Q and B bands of the octaaza-na phthalocyanine to the hollow octaaza-naphthalocyanine, therefore, the Q and B bands all have a blue shift.With the assistance of animated pictures produced on the basis of the normal coordinates, the vibration modes in the IR spectra of OANcGe,OANcSn and OANcPb were also identified. The purpose of this essay is to find out the octaaza-naphthalocyanine compounds better than the phthalocyanine compounds through a series research on the structure and optical properties of the IVA metal complexes of octaaza-naphthalocyanine.