A poly(phenylene ethynylene) conjugated polymer (PPE-NMe(3)(+)-COO(-)) containing tetraalkylammonium groups and carboxylate groups has been synthesized by Sonogashira coupling. Due to the presence of the strong cationic and weak anionic pendant units, the polymer undergoes a pH-induced transition from cationic polyelectrolyte to polyampholyte due to deprotonation of the carboxylic acid units in basic solution. Studies of the pH dependence of the polymers' optical properties reveal changes in absorption oscillator strength and fluorescence quantum efficiency that are triggered by the transition from cationic polyelectrolyte to polyampholyte nature. Stern-Volmer fluorescence quenching of PPE-NMe(3)(+)-COO(-) with a negatively charged quencher 1,4,5,8-naphthalenediimide-N,N-bis(methylsulfonate) (NDS) shows that the polymer fluorescence quenching is amplified at low pH where the polymer is a polycation, whereas the quenching efficiency is considerably less at high pH.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/la104586t | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Enhanced two-temperature model and its application in comprehensive analysis of femtosecond laser melting of gold, copper and their alloys.
Phys Chem Chem Phys
January 2025
Theoretical Physics Section, Bhabha Atomic Research Centre, Mumbai-400085, India.
Extensive research on ultrashort laser-induced melting of noble metals like Au, Ag and Cu is available. However, studies on laser energy deposition and thermal damage of their alloys, which are currently attracting interest for energy harvesting and storage devices, are limited. This study investigates the melting damage threshold (DT) of three intermetallic alloys of Au and Cu (AuCu, AuCu and AuCu) subjected to single-pulse femtosecond laser irradiation, comparing them with their constituent metals.
View Article and Find Full Text PDFCan Low Structural Anisotropy Produce High Optical Anisotropy? Anomalous Giant Optical Birefringent Effect in PIAlI in Focus.
J Am Chem Soc
January 2025
Functional Crystals Lab, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Tetrahedral halides with broad transparency and large second harmonic effects have the potential to serve as mid-infrared wide-bandgap materials with balanced nonlinear-optical (NLO) properties. However, their regular tetrahedral motifs tend to exhibit low optical birefringence (Δ < 0.03) due to limited structural anisotropy, which constrains their practical phase-matched capability.
View Article and Find Full Text PDFControlling Sign and Magnitude of Circularly Polarized Luminescence of Axially Chiral Schiff-Base Boron Difluoride Complexes Bearing Polyethylene Glycol Chains.
Chirality
January 2025
Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Japan.
The synthesis, structure, and circularly polarized luminescence (CPL) properties of axially chiral boron difluoride complexes are described. A series of optically pure bis (boron difluoride) complexes were prepared in 5 steps from commercially available (S)- or (R)-BINOL as starting materials. The complexes were found to exhibit similar yellow photoluminescence in solution, regardless of the type of substituents on the nitrogen atoms.
View Article and Find Full Text PDFBaFS: Birefringence Enhanced by the Transformation from Optical Isotropy to Anisotropy via Interlayer Anion Substitution.
Small
January 2025
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China.
Improved birefringence, given its capacity to modulate polarized light, holds a lively role in the optoelectronic industry. Traditionally, alkaline-earth metal halides have possessed low birefringence due to their nearly optical isotropic properties. Herein, the substitution of interlayer anion with linear S─S unit that meticulously engineered by reduced valence state and strong covalent bond is integrated into the optically isotropic BaF, offering the new salt-inclusion chalcogenide BaFS.
View Article and Find Full Text PDFA Bifunctional Peptide with Penetration Ability for Treating Retinal Angiogenesis via Eye Drops.
Mol Pharm
January 2025
Key Laboratory of Chemical Biology (Ministry of Education), NMPA Key Laboratory for Quality Research and Evaluation of Carbohydrate-based Medicine, Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 Wenhua West Road, Jinan 250012, China.
Numerous diseases, such as diabetic retinopathy and age-related macular degeneration, can lead to retinal neovascularization, which can seriously impair the visual function and potentially result in blindness. The presence of the blood-retina barrier makes it challenging for ocularly administered drugs to penetrate physiological barriers and reach the ocular posterior segments, including the retina and choroid. Herein, we developed an innovative bifunctional peptide, Tat-C-RP7, which exhibits excellent penetration capabilities and antiangiogenic properties aimed at treating retinal neovascularization diseases.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!