Spectroscopic and physicochemical behavior of magnesium phthalocyanine derivatives mono-substituted with a carboxylic acid group
- Nombona, Nolwazi, Chidawanyika, Wadzanai J U, Nyokong, Tebello
- Authors: Nombona, Nolwazi , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244450 , vital:51258 , xlink:href="https://doi.org/10.1016/j.molstruc.2011.12.051"
- Description: This work reports on the synthesis of novel unsymmetrically substituted magnesium phthalocyanine complexes containing one carboxyl group. The physicochemical behavior of these complexes were compared with those of their unmetallated and zinc counterparts. The MgPcs showed interesting absorption spectra with [8,15,22-Tris-(naphtho)-4,5-(3-carboxy-1,2-dioxyphenyl)phthalocyaninato]magnesium (II) showing a large split in the Q band whereas [8,15,22-Tris-(naphtho)-2-(carboxy) phthalocyaninato]magnesium(II) presented only a small splitting. The magnesium phthalocyanine derivatives displayed higher fluorescence quantum yields compared to unmetallated and zinc phthalocyanine counterparts. The latter gave admirable triplet and singlet oxygen quantum yields. These molecules can distinctly be employed in the field of photodynamic therapy in combination with fluorescence imaging.
- Full Text:
- Date Issued: 2012
- Authors: Nombona, Nolwazi , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244450 , vital:51258 , xlink:href="https://doi.org/10.1016/j.molstruc.2011.12.051"
- Description: This work reports on the synthesis of novel unsymmetrically substituted magnesium phthalocyanine complexes containing one carboxyl group. The physicochemical behavior of these complexes were compared with those of their unmetallated and zinc counterparts. The MgPcs showed interesting absorption spectra with [8,15,22-Tris-(naphtho)-4,5-(3-carboxy-1,2-dioxyphenyl)phthalocyaninato]magnesium (II) showing a large split in the Q band whereas [8,15,22-Tris-(naphtho)-2-(carboxy) phthalocyaninato]magnesium(II) presented only a small splitting. The magnesium phthalocyanine derivatives displayed higher fluorescence quantum yields compared to unmetallated and zinc phthalocyanine counterparts. The latter gave admirable triplet and singlet oxygen quantum yields. These molecules can distinctly be employed in the field of photodynamic therapy in combination with fluorescence imaging.
- Full Text:
- Date Issued: 2012
Synthesis and photophysical behavior of a novel zinc phthalocyanine containing a single carboxylic acid and three phenylthio substituents
- Forteath, Shaun, Antunes, Edith M, Chidawanyika, Wadzanai J U, Nyokong, Tebello
- Authors: Forteath, Shaun , Antunes, Edith M , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243207 , vital:51127 , xlink:href="https://doi.org/10.1016/j.jlumin.2012.03.050"
- Description: Zinc 2, (3)-tri-(phenylthio)-2, (3)-carboxy phthalocyanine (ZnPc(COOH)(SPh)3), zinc 2, (3)-tetra-(phenylthio) phthalocyanine (ZnPc(SPh)4) and 2, (3)-tetra-(phenylthio) phthalocyanine (H2Pc(SPh)4) were synthesized and their photophysical behavior were compared with those of a number of zinc phthalocyanine (ZnPc) derivatives. ZnPc(COOH)(SPh)3 and ZnPc(SPh)4 had similar fluorescence (ΦF=0.14) and triplet state (ΦT=0.65) quantum yields in dimethylsulfoxide, hence showing no effects of the replacement of one of the phenylthio groups with a carboxylic acid group. ZnPc(COOH)(SPh)3 displayed a slightly shorter triplet lifetime (τT=331 μs) than ZnPc (τT=350 μs) in DMSO, but within the range of ZnPc derivatives. The triplet lifetime for ZnPc(COOH)(SPh)3 is much longer than for the symmetrical derivative (ZnPc(SPh)4) with τT=149 μs in DMSO.
- Full Text:
- Date Issued: 2012
- Authors: Forteath, Shaun , Antunes, Edith M , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243207 , vital:51127 , xlink:href="https://doi.org/10.1016/j.jlumin.2012.03.050"
- Description: Zinc 2, (3)-tri-(phenylthio)-2, (3)-carboxy phthalocyanine (ZnPc(COOH)(SPh)3), zinc 2, (3)-tetra-(phenylthio) phthalocyanine (ZnPc(SPh)4) and 2, (3)-tetra-(phenylthio) phthalocyanine (H2Pc(SPh)4) were synthesized and their photophysical behavior were compared with those of a number of zinc phthalocyanine (ZnPc) derivatives. ZnPc(COOH)(SPh)3 and ZnPc(SPh)4 had similar fluorescence (ΦF=0.14) and triplet state (ΦT=0.65) quantum yields in dimethylsulfoxide, hence showing no effects of the replacement of one of the phenylthio groups with a carboxylic acid group. ZnPc(COOH)(SPh)3 displayed a slightly shorter triplet lifetime (τT=331 μs) than ZnPc (τT=350 μs) in DMSO, but within the range of ZnPc derivatives. The triplet lifetime for ZnPc(COOH)(SPh)3 is much longer than for the symmetrical derivative (ZnPc(SPh)4) with τT=149 μs in DMSO.
- Full Text:
- Date Issued: 2012
Unquenched fluorescence lifetime for β-phenylthio substituted zinc phthalocyanine upon conjugation to gold nanoparticles
- Forteath, Shaun, Antunes, Edith M, Chidawanyika, Wadzanai J U, Nyokong, Tebello
- Authors: Forteath, Shaun , Antunes, Edith M , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245774 , vital:51404 , xlink:href="https://doi.org/10.1016/j.poly.2011.12.015"
- Description: Photoinduced processes in phthalocyanine-functionalized gold nanoparticles have been investigated by spectroscopic measurements. The zinc phthalocyanine used contained four phenylthio peripheral substituents (ZnPc(SPh)4). The conjugates formed are represented as ZnPc(SPh)4–AuNP. The absorption spectrum of the ZnPc(SPh)4–AuNP shows a broadening of the phthalocyanine Q-band absorption, probably due to a tight packing of the phthalocyanines on the gold nanoparticle surface. For the attached phthalocyanines, the two fluorescence lifetimes obtained by time-correlated single photon counting (TCSPC) were determined to be both longer and shorter than that of the free Pc. The fluorescence lifetimes were resolved using time resolved fluorescence spectroscopy (TRES).
- Full Text:
- Date Issued: 2012
- Authors: Forteath, Shaun , Antunes, Edith M , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245774 , vital:51404 , xlink:href="https://doi.org/10.1016/j.poly.2011.12.015"
- Description: Photoinduced processes in phthalocyanine-functionalized gold nanoparticles have been investigated by spectroscopic measurements. The zinc phthalocyanine used contained four phenylthio peripheral substituents (ZnPc(SPh)4). The conjugates formed are represented as ZnPc(SPh)4–AuNP. The absorption spectrum of the ZnPc(SPh)4–AuNP shows a broadening of the phthalocyanine Q-band absorption, probably due to a tight packing of the phthalocyanines on the gold nanoparticle surface. For the attached phthalocyanines, the two fluorescence lifetimes obtained by time-correlated single photon counting (TCSPC) were determined to be both longer and shorter than that of the free Pc. The fluorescence lifetimes were resolved using time resolved fluorescence spectroscopy (TRES).
- Full Text:
- Date Issued: 2012
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