We synthesize and characterize derivatives of the two-dimensional hybrid perovskite (2DHP) phenethylammonium lead iodide ((PEA)PbI) in which the para H on the cation is replaced with F, Cl, CH, or Br. These substitutions increase the length of the cation but leave the cross-sectional area unchanged, resulting in structurally similar PbI frameworks with increasing interlayer spacing. Longer cations result in broader, blue-shifted excitonic absorption spectra with reduced or eliminated structure, indicating greater energetic disorder. Photoluminescence spectra are largely invariant and insensitive to cation length, suggesting polaron formation stabilizes a structural and electronic minimum. Temperature-dependent line width analysis reveals excitons couple to a vibration on the organic framework that is weakly sensitive to these cation substitutions, and Raman spectra and electronic structure calculations support the presence of such a cationic mode. Despite carriers being confined to the inorganic framework, the length of the organic cation alters the optical and electronic properties of 2DHPs.
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http://dx.doi.org/10.1021/acs.jpclett.9b00247 | DOI Listing |
Pharmaceutics
November 2024
Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA.
The effect of 2-hydroxpropyl-β-cyclodextrin (2HPβCD) with or without divalent metal ions (Ca, Mg, and Zn) on the stability of dalbavancin in acetate buffer was investigated. Dalbavancin recovery from formulations with 2HPβCD and divalent metal ions after four weeks of storage at 5 °C and 55 °C was measured by RP-HPLC and HP-SEC; a longer-term study was carried out over six months at 5 °C, 25 °C, and 40 °C. Binding of 2HPβCD was characterized by isothermal titration calorimetry (ITC) and nuclear magnetic resonance (NMR).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Biology, Indiana University, Bloomington, IN 47405.
Soft Matter
January 2025
Biophysical Chemistry Laboratory, Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India.
The adsorption and aggregation of amphiphiles at different solvent interfaces are of great scientific and technological importance. In this study, interfacial tension measurements of surface-active compounds-ionic liquid 2-dodecyl-2,2dimethylethanolammonium bromide (12Cho.Br) and cationic surfactant cetyltrimethylammonium bromide (CTAB)-were conducted both in the absence and presence of ciprofloxacin (CIP).
View Article and Find Full Text PDFJ Med Chem
January 2025
Department of Chemistry, University of Houston, 4800 Calhoun Rd., Houston, Texas 77204, United States.
We report the application of organoiridium complexes as catalytic agents for the detoxification of biogenic reactive aldehyde species (RASP), which are implicated in the pathogenesis of neurodegenerative disorders. We show that Ir complexes functionalized with phosphonium cations localize selectively in the mitochondria and have better cellular retention compared to that of their parent Ir species. In a cell model for Parkinsonism, the mitochondria-targeted iridium catalysts exhibited superior cell protecting abilities and longer-lasting effects (up to 6 d) than conventional RASP scavengers, which failed to be effective beyond 24 h.
View Article and Find Full Text PDFDrug Des Devel Ther
December 2024
Department of Anesthesiology, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan.
Purpose: Corneal pain is one of the most common eye symptoms caused by various types of epithelial injuries, including traumatic abrasion, chemical injury, ulcers, ultraviolet exposure, and infection. However, current therapeutic options for corneal pain are limited. In this study, we synthesized a novel quaternary ammonium compound, N-propylamiodarone bromide (NPA), and employed a rodent model of corneal injury to investigate whether NPA offers prolonged corneal analgesia through transient receptor potential vanilloid 1 (TRPV1) channel-mediated selective cellular entry, without hindering corneal epithelial recovery.
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