Photophysical and photochemical properties and TD-DFT calculations of novel zinc and platinum phthalocyanines

The synthesis and characterization, and spectral, photophysical and photochemical properties of dimethyl 2-(3-methylbut-2-enyl)malonate substituted zinc and platinum phthalocyanines are reported. The phthalocyanines were characterized by electronic absorption, infrared, and nuclear magnetic resonance spectroscopy, mass spectrometry and elemental analysis. Trends observed in the singlet oxygen, photodegradation, fluorescence and triplet state quantum yields and the fluorescence and triplet state lifetimes are described. DFT and TD-DFT calculations were carried out so that the electronic structure and optical spectroscopy of the Pt(II) complex could be compared to that of the Zn(II) complex. As would normally be anticipated, the bulky peripheral substituents were found to enhance the solubility of the complexes in organic solvents.