Photochemical and photophysical behaviour of porphyrins and phthalocyanines irradiated with ­violet or ultraviolet light

Tokumaru, Katsumi

doi:10.1002/1099-1409(200101)5:1<77::aid-jpp302>3.3.co;2-o

Cited by 25 publications

(48 citation statements)

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“…p * bands in the 400-600 nm region cannot be excluded as a possibility, however. This brings us to the assignment of the violet emission, which has sometimes been assigned to an np * excited state [7,[11][12][13][14] based on the assumption that np * states do not deactivate as efficiently to the S 1 state as the higher energy pp * states do [7,11].…”

Section: Resultsmentioning

confidence: 99%

“…p * in origin this assignment would still be problematic, however. The wavelength of violet emission lies significantly to the blue of a significant portion of the band envelope in the 400-600 nm region, both in the case of Zna(OC 4 H 9 ) 8 Pc [2][3][4][5][6][7][8][9][10][11][12][13][14] and the mixed alkoxy-and thioalkyl-substituted porphyrazines reported by Hoffman and coworkers [15,16]. This pattern can be observed in the emission spectra recorded during the irradiation of a tetrahydrofuran (THF) solution of H 2 a(SC 4 H 9 ) 8 Pc, Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The syntheses of zinc 1,4,8,11,15,18,22,25-octa-n-butoxyphthalocyanine (Zna(OC 4 H 9 ) 8 Pc), 1,4,8,11,15,18,22,25-octa-n-butoxyphthalocyanine (H 2 a(SC 4 H 9 ) 8 Pc) and zinc 1,4,8,11,15,18,22, 25-thio-n-butoxyphthalocyanine (Zna(SC 4 H 9 ) 8 Pc) [1] have been reported previously.…”

Section: Methodsmentioning

confidence: 99%

“…Sulfonated AlClPcs are currently being used commercially for this purpose in Russia [2]. In the emission spectra of alkoxy-and thioalkyl-substituted phthalocyanines and porphyrazines [3][4][5][6][7][8][9][10][11][12][13][14][15][16], an S 1 emission peak is observed in the 600-900 nm region, while a second higher energy peak has also frequently been reported in the 400-600 nm region. The higher energy emission has been assigned as S 2 emission and np * excited states associated with the lone pairs of the peripheral oxygen and/or sulfur atoms have sometimes been proposed as the origin of this peak [7,[11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Re-examination of the emission properties of alkoxy- and thioalkyl-substituted phthalocyanines

Mack

Kobayashi

Stillman

2010

Journal of Inorganic Biochemistry

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Re-examination of the emission properties of alkoxy- and thioalkyl-substituted phthalocyanines

Mack

Kobayashi

Stillman

2010

Journal of Inorganic Biochemistry

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“…Pzs exhibit dual fluorescence, much like phthalocyanines (16)(17)(18). Thus, 247 has intense NIR emission from the first (S 1 ) excited singlet state (Fig.…”

Section: Resultsmentioning

confidence: 99%

Chiral porphyrazine near-IR optical imaging agent exhibiting preferential tumor accumulation

Trivedi

Harney

Olive

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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A chiral porphyrazine (pz), H 2 [pz( trans - A 2 B 2 )] (247), has been prepared that exhibits preferential in vivo accumulation in the cells of tumors. Pz 247 exhibits near-infrared (NIR) emission with λ > 700 nm in the required wavelength range for maximum tissue penetration. When MDA-MB-231 breast tumor cells are treated with 247, the agent shows strong intracellular fluorescence with an emission maximum, 704 nm, which indicates that it localizes within a hydrophobic microenvironment. Pz 247 is shown to associate with the lipophilic core of LDL and undergo cellular entry primarily through receptor-mediated endocytosis accumulating in lysosomes. Preliminary in vivo studies show that 247 exhibits preferential accumulation and retention in the cells of MDA-MB-231 tumors subcutaneously implanted in mice, thereby enabling NIR optical imaging with excellent contrast between tumor and surrounding tissue. The intensity of fluorescence from 247 within the tumor increases over time up to 48 h after injection presumably due to the sequestration of circulating 247/LDL complex by the tumor tissue. As the need for cholesterol, and thus LDL, is elevated in highly proliferative tumor cells over nontumorigenic cells, 247 has potential application for all such tumors.

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Excited‐State Deactivation of Branched Phthalocyanine Compounds

et al. 2015

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The excited-state relaxation dynamics and chromophore interactions in two phthalocyanine compounds (bis- and trisphthalocyanines) are studied by using steady-state and femtosecond transient absorption spectral measurements, where the excited-state energy-transfer mechanism is explored. By exciting phthalocyanine compounds to their second electronically excited states and probing the subsequent relaxation dynamics, a multitude of deactivation pathways are identified. The transient absorption spectra show the relaxation pathway from the exciton state to excimer state and then back to the ground state in bisphthalocyanine (bis-Pc). In trisphthalocyanine (tris-Pc), the monomeric and dimeric subunits are excited and the excitation energy transfers from the monomeric vibrationally hot S1 state to the exciton state of a pre-associated dimer, with subsequent relaxation to the ground state through the excimer state. The theoretical calculations and steady-state spectra also show a face-to-face conformation in bis-Pc, whereas in tris-Pc, two of the three phthalocyanine branches form a pre-associated face-to-face dimeric conformation with the third one acting as a monomeric unit; this is consistent with the results of the transient absorption experiments from the perspective of molecular structure. The detailed structure-property relationships in phthalocyanine compounds is useful for exploring the function of molecular aggregates in energy migration of natural photosynthesis systems.

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Photochemical and photophysical behaviour of porphyrins and phthalocyanines irradiated with violet or ultraviolet light

Cited by 25 publications

References 0 publications

Re-examination of the emission properties of alkoxy- and thioalkyl-substituted phthalocyanines

Re-examination of the emission properties of alkoxy- and thioalkyl-substituted phthalocyanines

Chiral porphyrazine near-IR optical imaging agent exhibiting preferential tumor accumulation

Excited‐State Deactivation of Branched Phthalocyanine Compounds

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Photochemical and photophysical behaviour of porphyrins and phthalocyanines irradiated with ­violet or ultraviolet light

Cited by 25 publications

References 0 publications

Re-examination of the emission properties of alkoxy- and thioalkyl-substituted phthalocyanines

Re-examination of the emission properties of alkoxy- and thioalkyl-substituted phthalocyanines

Chiral porphyrazine near-IR optical imaging agent exhibiting preferential tumor accumulation

Excited‐State Deactivation of Branched Phthalocyanine Compounds

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Photochemical and photophysical behaviour of porphyrins and phthalocyanines irradiated with violet or ultraviolet light