Effects of environment on the photophysical characteristics of mesotetrakis methylpyridiniumyl porphyrin (TMPyP)

A study on the interactions of cationic porphyrin with nano clay platelets in Layer-by-Layer (LbL) self assembled films

“…Both B and Q band arise from π-π * transition and can be explained by the four orbital model of Gourterman [24]. The Soret band position is highly sensitive to microenvironment [7,25].…”

Influence of halogen atoms and protonation on the photophysical properties of sulfonated porphyrins

“…Usually, the photophysical processes involved in the excitedstate dynamics of porphyrins are described by a five-energy-level diagram (Figure 2), which includes the molecular ground singlet state (S 0 ), two excited singlet bands (S 1 and S 2 ), and two triplet bands (T 1 and T 2 ) [30,31]. In this energy diagram, the population is considered to be in the S 0 state in thermodynamic equilibrium and after the excitation, this population is redistributed among the singlet states (S 0 , S 1 and S n ).…”

“…In order to determine the triplet states characteristics ( 34 and isc ), we used the pulse train Z-scan technique (PT Z-scan) [30,31]. The PT Z-scan uses as pump source a frequency-doubled, Q-switched and mode-locked Nd:YAG laser, producing about twenty-five 70-ps pulses at 532 nm, separated by 13.2 ns.…”

“…Combination of Z-scan measurements, UV-vis absorption and fluorescence spectroscopies have allowed to find contributions from radiative, internal conversion and intersystem crossing processes, which allow evaluating its potential for optical applications [30,31]. In this way, the present work reports on the study of photophysical characteristics of sulfonated porphyrins and how they are influenced by presence of one or two halogens (fluorine of chlorine) in the ortho positions of phenyl rings and the macrocycle protonation.…”

“…The Z-scan technique was shown to be an appropriated and powerful tool to investigate nonlinear properties and photophysical characteristics of organic molecules aiming at applications in photonic and photomedicine [27][28][29][30][31]. Combination of Z-scan measurements, UV-vis absorption and fluorescence spectroscopies have allowed to find contributions from radiative, internal conversion and intersystem crossing processes, which allow evaluating its potential for optical applications [30,31].…”