scholarly journals Spectral properties and photophysical behaviour of water soluble cationic Mg(II) and Al(III) phthalocyanines

2014 ◽  
Vol 12 (3) ◽  
pp. 403-415 ◽  
Author(s):  
Mopelola Idowu ◽  
Yasin Arslanoğlu ◽  
Tebello Nyokong

AbstractPeripherally and non-peripherally tetrasubstituted-[(N-methyl-2-pyridylthio)]phthalocyaninato magnesium (II) (5 and 6) and chloro aluminium (III) (7 and 8) tetraiodide have been synthesized and characterized. The photophysical properties of the complexes in dimethyl sulfoxide (DMSO) and aqueous medium in the presence and absence of cremophore EL have been studied. These complexes show high solubility in aqueous medium though they were aggregated. The triplet state quantum yields (FT) and the triplet lifetimes (tT) were found to be higher in DMSO with ΦT ranging from 0.32 to 0.51, while tT ranged from 282 to 622 ms in DMSO, compared to aqueous medium (pH 7.4 buffer) where ΦT ranged from 0.15 to 0.19 and tT from 26 to 35 ms. Addition of cremophore EL in aqueous solution resulted in partial disaggregation and increased photoactivity. The fluorescence lifetimes of the complexes showed strong dependence on their immediate environment. The ionic magnesium(II) and aluminium(III) phthalocyanines strongly bind to bovine serum albumin (BSA).

2005 ◽  
Vol 09 (07) ◽  
pp. 476-483 ◽  
Author(s):  
Itumeleng Seotsanyana-Mokhosi ◽  
Tebello Nyokong

Spectral properties of a water soluble metal free tetracarboxyphenoxy bisnaphthalophthalocyanine (3) were studied in water and organic solvents. It was found that in protic solvents, complex 3 was highly aggregated. The surfactant, Triton X100, and bovine serum albumin (BSA) do not effect disaggregation while cetyl trimethylammonium chloride (CTAC) caused the molecule to disaggregate. The fluorescence quantum yields were higher in the presence of CTAC. Studying the interaction of BSA with complex 3 using fluorometry revealed that BSA is highly quenched by the latter. A 1:1 stoichiometric binding ratio between BSA and the Pc was found. Triplet quantum yields in water containing CTAC were higher than in organic solvents.


2021 ◽  
Author(s):  
Mikhail Yu Belikov ◽  
Mikhail Yur'evich Ievlev ◽  
Ivan Nikolaevich Bardasov

A directed synthesis of the first nitrile-rich dye showing visible-light-induced negative photochromism in aqueous medium was implemented. The possibility to change the color of an aqueous solution from yellow to...


2006 ◽  
Vol 10 (01) ◽  
pp. 33-42 ◽  
Author(s):  
Myriam E. Rodriguez ◽  
Daniel A. Fernández ◽  
Josefina Awruch ◽  
Silvia E. Braslavsky ◽  
Lelia E. Dicelio

The photophysical properties of tetrakis(1,1-dimethyl-2-trimethylammonium)ethylphthalocyaninato zinc(II) tetraiodide (I) – a water-soluble cationic phthalocyanine – are presented in the presence of human serum albumin (HSA) and in micelles of sodium dodecylsulfate ( SDS ) and hexadecyltrimethylammonium chloride ( CTAC ). Spectrophotometric measurements showed that the surfactants SDS and CTAC induce monomerization of I, although the latter less efficiently than the former. This effect is less pronounced in the presence of HSA. The strength of this effect is evaluated through dimerization constants, which are Kd = (5 ± 1) × 105 m−1 in SDS , (1.5 ± 0.5) × 106 M −1 in CTAC , and (1.8 ± 0.9) × 106 M −1 in HSA. Fluorescence experiments confirm that aggregation of I drops as the concentration of surfactant is raised. Triplet quantum yields also decreased upon aggregation and were Φ T = 0.59, 0.16, and < 0.01 in SDS , CTAC , and HSA, respectively. These results indicate that the affinity of I for the environment is not just due to ionic interactions; hydrophobic interactions play an equally important role.


2017 ◽  
Vol 72 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Yuling Xu ◽  
Stephen Opeyemi Aderinto ◽  
Huilu Wu ◽  
Hongping Peng ◽  
Han Zhang ◽  
...  

AbstractA new Schiff base, 4-allylamine-N-(N-5-methylsalicylidene)-1,8-naphthalimide (1), has been designed and synthesized by combining a 1,8-naphthalimide moiety as a fluorophore and a Schiff base as a recognition group. Its photophysical properties were investigated by absorption and fluorescence spectroscopy, and this sensor exhibits a high fluorescence quantum yield of 0.75–0.91 inorganic solvents of different polarity. It also shows high selectivity for Cu2+ over other ions with fluorescence quenching in aqueous medium (pH=7.2). The reason for this phenomenon (fluorescence quenching) is attributed to the formation of a 1:1 complex between 1 and Cu2+ according to the Job plot and fluorescence titration. The sensor can be applied to the quantification of Cu2+ in a linear fashion from 0.5 to 5 μM with a detection limit of 0.23 μM. Additionally, the association constant (Ka) between Cu2+ and 1 is 1.328×106 M−1 in aqueous media.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
A. A. Chernonosov ◽  
E. A. Ermilov ◽  
B. Röder ◽  
L. I. Solovyova ◽  
O. S. Fedorova

Water solubility of phthalocyanines (Pcs) usually increases by the introduction of charged or carboxy substituents in the peripheral positions of the macrocycle. As a result, such structural changes influence their photophysical and photochemical properties as photosensitizers. Phthalocyanines substituted with four or eight terminal carboxyl groups and having in some cases additional eight positive charges (water soluble phthalocyanines) were studied in order to evaluate the spectroscopic and photophysical effects of these side residues on the chromophore properties. The quantum yield of singlet oxygen (O12) generation, the triplet-triplet absorption, and the transient absorption spectra were measured and linked to the structure of the substituents. It was shown that charged substituents did not change the quantum yields ofO12generation but decrease its lifetimes. The introduction of the charged substituents not only increases the water solubility but also significantly changes absorption, fluorescence, and transient absorption spectra of water soluble Pcs.


2007 ◽  
Vol 11 (06) ◽  
pp. 448-454 ◽  
Author(s):  
Masakazu Nishida ◽  
Atsuya Momotake ◽  
Yoshihiro Shinohara ◽  
Yoshinobu Nishimura ◽  
Tatsuo Arai

Aggregation behaviors of phthalocyanine derivatives which have a dendritic structure were examined in an aqueous solution. We prepared the first- and second-generation dendrimers (WG1-PC and WG2-PC), having water-soluble substituents as a peripheral group, to be resolved in water. From spectroscopic measurement, WG2-PC acted in a monomeric manner, even in an aqueous solution, in contrast to WG1-PC, which exhibited spectra attributed to aggregation. This implies that a higher generation of water-soluble dendrimers can prevent a phthalocyanine core from forming an aggregation. The introduction of the second-generation dendrons to an aggregatable core may be effective to avoid self-aggregation and an undesirable deactivation process.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Riki Kadokawa ◽  
Tetsuo Fujie ◽  
Gyanendra Sharma ◽  
Kojiro Ishibashi ◽  
Kazuaki Ninomiya ◽  
...  

AbstractTrimethylglycine (TMG) is a cheap, natural, and highly biocompatible compound. Therefore, it has been used in the fields of food and life sciences, but the application of solid TMG is limited to utilisation as an “additive”. In the present study, we focussed on the high solubility of TMG in water, derived from the aprotic zwitterionic structure, and proposed TMG as the chemical accounting for a major portion of the aqueous solution (e.g., 50 wt%). High loading of TMG shifted the properties of water and enabled the dissolution of poorly water-soluble cisplatin, an anticancer agent, at high concentration (solubility of cisplatin: 0.15 wt% in water vs 1.7 wt% in TMG aqueous solution). For hepatic arterial infusion, this can reduce the amount of cisplatin administered from 40 to 4 mL. It enables simple injection using a syringe, without the need for catheters and automatic pumps, leading to critical alleviation of the risk to patients. Furthermore, we produced a dry powder from a cisplatin-containing TMG aqueous solution via freeze-drying. Powders can be conveniently stored and transported. Furthermore, cisplatin is often used as a mixture with other drugs, and cisplatin aqueous solutions are not preferred as they dilute the other drugs.


2010 ◽  
Vol 14 (11) ◽  
pp. 968-974 ◽  
Author(s):  
Nina A. Kuznetsova ◽  
Dmitry A. Makarov ◽  
Olga A. Yuzhakova ◽  
Ludmila I. Solovieva ◽  
Oleg L. Kaliya

The photodegradation of a series of water-soluble Zn(II) and Al(III) phthalocyanines has been studied in aerobic aqueous solutions. The photobleaching quantum yields of zinc phthalocyanine derivatives range from 2.2 × 10-4 for octacarboxy- to 1.5 × 10-5 for ZnPc , bearing 16 positively charged groups on periphery. Their aluminum counterparts are more photostable and photobleach with quantum yields in the narrow range (0.75 ÷ 2 × 10-6). The pH dependences of the photobleaching quantum yields for aluminum phthalocyanines show enhanced photodegradation for molecules with deprotonated axial H2O ligand. Some aspects of the mechanism of dyes photodegradation were studied and discussed. It was found that contribution to photooxidation of type II pathways depends upon a particular dye structure. Thus, no contribution of singlet oxygen to the photooxidation of cationic phthalocyanines has been found, even though singlet oxygen is involved in the photodegradation of negatively charged phthalocyanines.


2020 ◽  
Vol 996 ◽  
pp. 82-87
Author(s):  
Shu Guo Dong ◽  
Gui Hua Cui ◽  
Qian Duan

A novel end-functionalized glycopolymer poly (3-O-methacryloyl-D-glucofuranose) -b-poly (2-Diethylaminoethyl Methacrylate) (PMAGlc-b-PDEA-ZnTAPc) with zinc (II) teraamaninophthalocyanine was synthesized. First, a pH-responsive copolymer PMAIpG-b-PDEA was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Then PMAIpG-b-PDEA reacted with ZnTAPc and deprotected to form a water-soluble and pH-responsive photosensitizer. The structure of the PMAGlc-b-PDEA-ZnTAPc was characterized by 1H NMR and GPC. The photophysical properties were evaluated by UV-Vis and fluorescence spectra. The PMAGlc-b-PDEA-ZnTAPc can generate singlet oxygen species with good singlet oxygen quantum yields (Φ△=0.38), which is believed to be the major cytotoxic reactive oxygen species (ROS) for photodynamic therapy. The ZnPc functionalized glycopolymer will be used as a potential photosensitizer in the fields of photodynamic therapy.


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