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

Abstract

The interactions of nonionic meso-tetra(p-hydroxyphenyl)porphyrin (THPP) with CX3COOH (X = F, Cl, Br) in Triton X-100 (TX) micellar solution have been investigated by optical absorption, resonance light-scattering, and fluorescence spectroscopies. The double red-shifted absorption bands and strong resonance light scattering (RLS) signal imply that the assemblies induced by trihalo acetic acids belong to J-aggregates. The fluorescence of porphyrin is quenched due to the aggregate formation. The kinetics of assemblies trigged by CBr3COOH is studied via stopped-flow techniques. No characteristics of autocatalyzed reactions are observed, and there is only a log phase. The nature of the exciton coupling of transition dipole moment can be systematically changed by the haloid substituents of the organic counteranion.

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

“…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.…”

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

“…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…”

“…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.…”

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

“…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.…”