Photo-induced anticancer activity and singlet oxygen production of prodigiosenes

The photo-induced cytotoxicity of prodigiosenes is reported. One prodigiosene represents a synthetic analogue of the natural product prodigiosin, and two are conjugated to molecules that target the estrogen receptor (ER). A comparison of incubation and irradiation frameworks for the three prodigiosenes is reported, with activity against ER- and ER+ lines explored. Furthermore, the ability of the three prodigiosenes to photosensitise the production of singlet oxygen is demonstrated, shedding mechanistic light onto possible photodynamic therapeutic effects of this class of tripyrroles.

Synthesis of alkylthio substituted pyridoporphyrazines and their photophysicochemical properties

Phthalocyanine and their related compounds are utilized as various applications, such as photosensitizing agents for photodynamic therapy of cancer. In this study, zinc bis(thiodidecylbenzo)-bis(pyrido)porphyrazines, especially zinc bis(1,4-didecylthiobenzo)-bis(3,4-pyrido)porphyrazine and zinc bis(1,4-didecylthiobenzo)-bis(2,3-pyrido)porphyrazine were synthesized. Quaternation of the pyridine nitrogen in these provides an amphiphilic property. Photoexcited triplet lifetime of synthesized and quaternized zinc bis(1,4-didecylthiobenzo)-bis(3,4-pyrido)porphyrazine and zinc bis(1,4-didecylthiobenzo)-bis(2,3-pyrido)porphyrazine were reported using laser-flash photolysis and singlet oxygen quantum yields by the 1,3-diphenylisobenzofurne method.

Synthesis of arylsulfanyl-subphthalocyanines and their ring expansion reaction

For dye-sensitized solar cells, phthalocyanines require strong absorption of far-red light between 700 and 850 nm because of their high electron transfer efficiency. Nevertheless phthalocyanines lack of affinity to basal plats, they inhibit utilization as dye-sensitized solar cell photosensitizer. Then, subphthalocyanines are used as precursors to prepare asymmetric 3:1 type phthalocyanines using a ring-enlargement technique to give affinity to basal plates. As subphthalocyanines having arylsulfanyl substituents used as a precursor, asymmetric phthalocyanines are expected to have good affinity to basal plates. Spectroscopic properties and electron transfer abilities to synthesize non-peripheral arylsulfanyl-subphthalocyanines were estimated. In addition to prepare as trial, asymmetric 3:1 type phthalocyanine, hexakis[(4-methylphenyl)thio]phthalocyanine, was synthesized from corresponding subphthalocyanine.

Heteroatom-substituted tetra(3,4-pyrido)porphyrazines: a stride toward near-infrared-absorbing macrocycles

Synthesis and photophysical properties are reported for substituted tetra(3,4-pyrido)porphyrazines that absorb light as far as at 800 nm.

Ultrafast charge transfer in nickel phthalocyanine probed by femtosecond Raman-induced Kerr effect spectroscopy

The recently developed technique of femtosecond stimulated Raman spectroscopy, and its variant, femtosecond Raman-induced Kerr effect spectroscopy (FRIKES), offer access to ultrafast excited-state dynamics via structurally specific vibrational spectra. We have used FRIKES to study the photoexcitation dynamics of nickel(II) phthalocyanine with eight butoxy substituents, NiPc(OBu)8. NiPc(OBu)8 is reported to have a relatively long-lived ligand-to-metal charge-transfer (LMCT) state, an essential characteristic for efficient electron transfer in photocatalysis. Following photoexcitation, vibrational transitions in the FRIKES spectra, assignable to phthalocyanine ring modes, evolve on the femtosecond to picosecond time scales. Correlation of ring core size with the frequency of the ν10 (asymmetric C-N stretching) mode confirms the identity of the LMCT state, which has a ∼500 ps lifetime, as well as that of a precursor d-d excited state. An even earlier (∼0.2 ps) transient is observed and tentatively assigned to a higher-lying Jahn-Teller-active LMCT state. This study illustrates the power of FRIKES spectroscopy in elucidating ultrafast molecular dynamics.