Optical Limiting Effect of New Synthesized Phthalocyanines in Solution and in Solid State

The major aim of this study was to design the synthesis of phthalocyanines that will be used as good optical limiters. The tin and germanium were chosen as atoms incorporated in the phthalocyanine ring owing to their charge of 4 allowing axial substitution. The possibility of axial substitution enhances largely solubility and prevents aggregation and further alters the packing of the molecule in solid state. Additionally, the axial ligands can introduce a dipole moment perpendicular to the macrocycle and consequently improve the NLO properties for example a magnitude of the third-order nonlinearity (3) [21, 22]. The second reason to choose tin and germanium was to compare the influence of heavier atom as tin on the optical limiting effect. Additionally, syntheses of phthalocyanines were intended to introduce electron-withdrawing groups in annulene rings in order to alteration the electronic properties and transition dipole moment.