Nonlinear absorption and excited state dynamics of porphyrin and phthalocyanine in the presence of explosive molecules

• Published in: Chemical physics letters 2015-11, Vol.641, p.23-28
• Main Authors: Anusha, P.T., Thomas, A.R., Philip, R., Rao, S. Venugopal
• Format: Article
• Language: English
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2015.10.049

•Nonlinear absorption of a porphyrin, phthalocyanine studied in presence of explosive molecules.•Excited state decay times calculated in the presence of explosive molecule.•NLA coefficients increased with increase in concentration of quencher molecules.•Excited state decay times decreased with increase in concentration of quencher molecules. Nonlinear absorption (NLA) properties and excited state dynamics of a porphyrin and phthalocyanine in the presence of explosive molecules were investigated using the nanosecond Z-scan and femtosecond pump-probe techniques, respectively. The NLA coefficients Is and β increased in the presence of explosive molecules. The change in first excited state decay time was evaluated through degenerate pump-probe measurements near 700nm and it was observed that decay time decreased in the presence of explosive molecules. The reduction in decay time and increase in NLA coefficients varied with different molecules according to their absorption, emission properties and affinity towards the explosive molecule.