A novel axially palladium (II)-Schiff base complex substituted silicon (IV) phthalocyanine
- Sen, Pinar, Nyokong, Tebello
- Authors: Sen, Pinar , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186813 , vital:44536 , xlink:href="https://doi.org/10.1016/j.poly.2019.114135"
- Description: In this study, a novel silicon(IV) phthalocyanine is reported for the first time as a phthalocyanine derivative bearing axially a palladium(II)-Schiff base complex. The photophysical and photochemical properties of the new Si(IV)Pc, such as absorption, fluorescence, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were measured in DMSO. The new silicon phthalocyanine displayed very low fluorescence, showing efficient intersystem crossing resulting in high triplet and high singlet oxygen quantum yields in DMSO. When compared with the unsubstituted SiPcCl2, the singlet oxygen quantum yield value (UD = 0.47) in relation to the triplet quantum yield (UT = 0.82), which is an important determinant for PDT applications, increased. The photodynamic antimicrobial chemotherapy activity (PACT) of new Si(IV)Pc towards Staphylococcus aureus was determined in comparison to the unsubstituted SiPcCl2. The results of the photodynamic antimicrobial effect study demonstrated that the Pd(II) complex substituted SiPc (5) possesses excellent photodynamic activity with a reduction percentage value of 99.94% and a log red value of 3.26.
- Full Text:
- Date Issued: 2019
- Authors: Sen, Pinar , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186813 , vital:44536 , xlink:href="https://doi.org/10.1016/j.poly.2019.114135"
- Description: In this study, a novel silicon(IV) phthalocyanine is reported for the first time as a phthalocyanine derivative bearing axially a palladium(II)-Schiff base complex. The photophysical and photochemical properties of the new Si(IV)Pc, such as absorption, fluorescence, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were measured in DMSO. The new silicon phthalocyanine displayed very low fluorescence, showing efficient intersystem crossing resulting in high triplet and high singlet oxygen quantum yields in DMSO. When compared with the unsubstituted SiPcCl2, the singlet oxygen quantum yield value (UD = 0.47) in relation to the triplet quantum yield (UT = 0.82), which is an important determinant for PDT applications, increased. The photodynamic antimicrobial chemotherapy activity (PACT) of new Si(IV)Pc towards Staphylococcus aureus was determined in comparison to the unsubstituted SiPcCl2. The results of the photodynamic antimicrobial effect study demonstrated that the Pd(II) complex substituted SiPc (5) possesses excellent photodynamic activity with a reduction percentage value of 99.94% and a log red value of 3.26.
- Full Text:
- Date Issued: 2019
New type of metal-free and Zinc (II), In (III), Ga (III) phthalocyanines carrying biologically active substituents: Synthesis and photophysicochemical properties and photodynamic therapy activity
- Sen, Pinar, Managa, Muthumuni, Nyokong, Tebello
- Authors: Sen, Pinar , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186971 , vital:44552 , xlink:href="https://doi.org/10.1016/j.ica.2019.03.010"
- Description: This study reports on novel phthalocyanines having benzimidazole units which are known to have biological properties. 4-(4-(5-chloro-1H-benzo[d]imidazol-2-yl) substituted metal-free, Zn(II), In(III) and Ga(III) phthalocyanines were synthesized, these newly synthesized molecules that were substituted by oxygen bridges were fully characterized. For the purpose of determining their potency for photodynamic therapy, the photophysicochemical properties were investigated in DMSO. The H2Pc (4) showed higher fluorescence quantum yield and fluorescence lifetime as compared to metallated phthalocyanines derivatives. However, the highest singlet oxygen (ΦΔ) and triplet state quantum yields (ΦT) values were obtained with the In(III)Pc (5).
- Full Text:
- Date Issued: 2019
- Authors: Sen, Pinar , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186971 , vital:44552 , xlink:href="https://doi.org/10.1016/j.ica.2019.03.010"
- Description: This study reports on novel phthalocyanines having benzimidazole units which are known to have biological properties. 4-(4-(5-chloro-1H-benzo[d]imidazol-2-yl) substituted metal-free, Zn(II), In(III) and Ga(III) phthalocyanines were synthesized, these newly synthesized molecules that were substituted by oxygen bridges were fully characterized. For the purpose of determining their potency for photodynamic therapy, the photophysicochemical properties were investigated in DMSO. The H2Pc (4) showed higher fluorescence quantum yield and fluorescence lifetime as compared to metallated phthalocyanines derivatives. However, the highest singlet oxygen (ΦΔ) and triplet state quantum yields (ΦT) values were obtained with the In(III)Pc (5).
- Full Text:
- Date Issued: 2019
Synthesis and photophysicochemical properties of novel axially di-substituted silicon (IV) phthalocyanines and their photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus
- Sen, Pinar, Sindelo, Azole, Mafukidze, Donovan M, Nyokong, Tebello
- Authors: Sen, Pinar , Sindelo, Azole , Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186757 , vital:44531 , xlink:href="https://doi.org/10.1016/j.synthmet.2019.116203"
- Description: In this study, novel silicon (IV) phthalocyanine axially di-substituted with benzimidazole moieties (3) and its quaternized derivative (4) have been synthesized and fully characterized. The photophysical and photochemical properties of both phthalocyanines such as absorption, fluorescence and, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were investigated in solutions. These new silicon phthalocyanines exhibited low fluorescence but produced high singlet oxygen yields in both DMSO (compound 3 and 4) and aqueous media (compound 4). The quaternization of Si(IV)Pc (3) improved the triplet state quantum yield (ΦT) 0.61 to 0.83, consequently singlet oxygen generation (ΦΔ) increased to 0.69 from 0.42. Photodynamic antimicrobial chemotherapy activities (PACT) of Si(IV)Pc photosensitizers were determined towards Staphylococcus aureus. The higher efficiency was obtained with cationic derivative (4) giving reduction percentage value of 99.75%.
- Full Text:
- Date Issued: 2019
- Authors: Sen, Pinar , Sindelo, Azole , Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186757 , vital:44531 , xlink:href="https://doi.org/10.1016/j.synthmet.2019.116203"
- Description: In this study, novel silicon (IV) phthalocyanine axially di-substituted with benzimidazole moieties (3) and its quaternized derivative (4) have been synthesized and fully characterized. The photophysical and photochemical properties of both phthalocyanines such as absorption, fluorescence and, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were investigated in solutions. These new silicon phthalocyanines exhibited low fluorescence but produced high singlet oxygen yields in both DMSO (compound 3 and 4) and aqueous media (compound 4). The quaternization of Si(IV)Pc (3) improved the triplet state quantum yield (ΦT) 0.61 to 0.83, consequently singlet oxygen generation (ΦΔ) increased to 0.69 from 0.42. Photodynamic antimicrobial chemotherapy activities (PACT) of Si(IV)Pc photosensitizers were determined towards Staphylococcus aureus. The higher efficiency was obtained with cationic derivative (4) giving reduction percentage value of 99.75%.
- Full Text:
- Date Issued: 2019
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