Ali Zare - Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
Mahmoud Mirzaei - Department of Biomaterials, Nanotechnology and Tissue Engineering, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
Mahboubeh Rostami - Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
Elham Jafari - Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran

In this work, phthalocyanine and its OCH۳ derivatives were investigated to see their photosensitization characteristics for producing singlet molecular oxygen, which is important in photodynamic therapy type-II. All structures were first optimized to achieve the minimized energy ۳D models Subsequently, they were prepared for the photosensitization investigations. All the experiments were conducted based on the density functional theory calculations. The energy absorption and emission observed between the occupied and unoccupied molecular orbitals based on the required energy for excitation and the corresponding energy of emission. The results indicated that the OCH۳ models could be expected to be safer than the original phthalocyanin by their required energy at longer wavelengths. The ratio of singlet molecular oxygen generation was found to be ۱:۱ for each of the OCH۳ derivatives. 

Phthalocyanine, Photosensitizer, Singlet molecular oxygen, Density functional theory