Exciton Coupling of Tetra(<i>p</i>-hydroxyphenyl)porphyrin Controlled by Substituents of Counterions in Triton X-100 Micellar Solution

Li, Xiwen; Li, Deijia; Zeng, Wei; Zou, Guolin; Chen, Zhangping

doi:10.1021/jp0669815

Cited by 16 publications

(13 citation statements)

References 34 publications

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“…28 Zou and Chen et al have investigated the interaction between THPP and TX-100 in aqueous solution and raised that porphyrin molecules insert mostly into the hydration layer and are stabilized by hydrogen-bonding and hydrophobic interactions between the porphyrin and the polyoxyethylene. 29,30 As they stated, the hydration layer exhibits a low-polarity with respect to water solution. Therefore, the relatively low polarity of the hydration layer constructed by the polyoxyethylene chains is probably favorable for the residence of the deprotonated TPPS monomer, which markedly shifts the equilibrium between H 4 TPPS 2À and H 2 TPPS 4À towards the deprotonated direction.…”

Section: Polymer-containing and Tpps-containing Emulsionsmentioning

confidence: 97%

Complex aggregation of TPPS and PEG-b-P4VP in confined space

Tao

Zhao

et al. 2010

Phys. Chem. Chem. Phys.

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To explore the structure and property features of complex aggregates assembled by polymer and organic dye molecules in microcosmic soft confined space, a three-dimensional microconfinement is constructed by W/O inverse emulsion as the site for the complex aggregation of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) and poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG-b-P4VP). It is found that porphyrin molecules exist in emulsion droplets mainly as the deprotonated monomer form, even though the pH of the water phase is much lower than the pK(a) of TPPS in bulk (pK(a)≈ 4.7). In spatially confined circumstances, upon blending of the single-component emulsions, complex aggregates are formed due to the thermodynamic collision of emulsion droplets and the subsequent electrostatic interaction between TPPS and polymer. The resultant novel complexes possess a relatively precise structure and homogenous core consisting of a porphyrin and P4VP block. Upon emulsion-breaking, the metastable complex kinetic intermediates generated in original acidic emulsion droplets display a remarkable trend of reaggregation within a certain period of time followed by a disassociation and redispersion. Complex aggregates with some novel morphologies are observed. The final product has a core-shell structure with the electrostatic complex of deprotonized porphyrin molecules homogenously dispersing in the P4VP clew as the core and the soluble PEG as the shell. However, those complexes produced in basic emulsion droplets exhibit a relatively higher stability against further aggregation after breakage of emulsion.

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Section: Polymer-containing and Tpps-containing Emulsionsmentioning

confidence: 97%

Complex aggregation of TPPS and PEG-b-P4VP in confined space

Tao

Zhao

et al. 2010

Phys. Chem. Chem. Phys.

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“…In this case both higher‐energy and lower‐energy, partially superposed, bisignated negative bands are observed, indicating formation of chiral species of either H‐like or J‐like character, as formerly shown by UV/Vis spectroscopy (Figure 2 B). 23…”

Section: Resultsmentioning

confidence: 99%

“…In this case both higher-energy and lower-energy, partially superposed, bisignated negative bands are observed, indicating formation of chiral species of either H-like or J-like character, as formerly shown by UV/Vis spectroscopy (Figure 2 B). [23] The CD spectrum of H 2 DGS-P in pure DMAc ( Figure 3) features an ICD band due to electronic interaction of the steroid moieties with the tetrapyrrolic platform. Significantly, in this case solvent-driven aggregation occurs with the formation of strongly CD active species, with intense nega-tive bisignated Cotton effect, as a consequence of strong electronic coupling between the macrocycles.…”

Section: Wwwchemeurjorgmentioning

confidence: 99%

Spectroscopic, Morphological, and Mechanistic Investigation of the Solvent‐Promoted Aggregation of Porphyrins Modified in meso‐Positions by Glucosylated Steroids

Zelenka

Trnka

Tišlerová

et al. 2011

Chemistry A European J

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Solvent‐driven aggregation of a series of porphyrin derivatives was studied by UV/Vis and circular dichroism spectroscopy. The porphyrins are characterised by the presence in the meso positions of steroidal moieties further conjugated with glucosyl groups. The presence of these groups makes the investigated macrocycles amphiphilic and soluble in aqueous solvent, namely, dimethyl acetamide/water. Aggregation of the macrocycles is triggered by a change in bulk solvent composition leading to formation of large architectures that express supramolecular chirality, steered by the presence of the stereogenic centres on the periphery of the macrocycles. The aggregation behaviour and chiroptical features of the aggregates are strongly dependent on the number of moieties decorating the periphery of the porphyrin framework. In particular, experimental evidence indicates that the structure of the steroid linker dictates the overall chirality of the supramolecular architectures. Moreover, the porphyrin concentration strongly affects the aggregation mechanism and the CD intensities of the spectra. Notably, AFM investigations reveal strong differences in aggregate morphology that are dependent on the nature of the appended functional groups, and closely in line with the changes in aggregation mechanism. The suprastructures formed at lower concentration show a network of long fibrous structures spanning over tens of micrometres, whereas the aggregates formed at higher concentration have smaller rod‐shaped structures that can be recognised as the result of coalescence of smaller globular structures. The fully steroid substituted derivative forms globular structures over the whole concentration range explored. Finally, a rationale for the aggregation phenomena was given by semiempirical calculations at the PM6 level.

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“…Organophosphorus pesticides (OPPs) have been used widely to prevent crops, vegetable, and cereals from being attacked by insects. OPPs have anticholinesterase activity in the nervous system, and exposure to high levels can lead to acute food poisoning, potentially causing death [3]. In general, trace determination of OPPs in rice usually requires a samplepreparation step before chromatographic analysis.…”

Section: Introductionmentioning

confidence: 99%

Trace analysis of some organophosphorus pesticides in rice samples using ultrasound‐assisted dispersive liquid–liquid microextraction and high‐performance liquid chromatography

Sharafi

Fattahi

Mahvi

et al. 2015

J of Separation Science

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An ultrasound-assisted dispersive liquid-liquid microextraction based on solidification of a floating organic drop method followed by high-performance liquid chromatography was developed for the extraction, preconcentration, and determination of trace amounts of organophosphorus pesticides in rice samples. Variables affecting the performance of both steps were thoroughly investigated. Some effective parameters on extraction were studied and optimized. Under the optimum conditions, recoveries for rice sample are in the range of 58.0-66.0%. The calibration graphs are linear in the range of 4-800 μg/kg and, limits of detection and limits of quantification are in the range of 1.5-3 and 4.2-8.5 μg/kg, respectively. The relative standard deviation for 50.0 μg/kg of organophosphorus pesticides in rice sample are in the range of 4.4-5.1% (n = 5). The obtained results show that proposed method is a fast and simple method for the determination of pesticides in cereals.

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Exciton Coupling of Tetra(p-hydroxyphenyl)porphyrin Controlled by Substituents of Counterions in Triton X-100 Micellar Solution

Cited by 16 publications

References 34 publications

Complex aggregation of TPPS and PEG-b-P4VP in confined space

Complex aggregation of TPPS and PEG-b-P4VP in confined space

Spectroscopic, Morphological, and Mechanistic Investigation of the Solvent‐Promoted Aggregation of Porphyrins Modified in meso‐Positions by Glucosylated Steroids

Trace analysis of some organophosphorus pesticides in rice samples using ultrasound‐assisted dispersive liquid–liquid microextraction and high‐performance liquid chromatography

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