Various room-temperature-stable monoorganylpolysulfanides of the form [X][RS] (X = [PPh], [PNP], [NEt]; R = Ph, -Bu, ≥ 2) were synthesized in a simple and versatile one-step process starting from sodium thiolates and elemental sulfur. The compounds were characterized by X-ray crystal structure analysis, NMR spectroscopy, microelemental analysis, and electrospray mass ionization spectrometry including collision-induced dissociation experiments. While these salts are well-defined species as crystals, they undergo complex equilibria in solution. In one case, compounds ranging from = 1-8 have been observed in solution. Structural features, dynamics in solution, as well as thermochromic properties of one of the compounds, [PPh][PhS], are investigated in detail by temperature- and pressure-dependent X-ray crystal structure analysis. The experimental data are complemented by periodic boundary density functional theory calculations on the crystal structures, as well as energy decomposition analyses.
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http://dx.doi.org/10.1021/acs.inorgchem.0c01426 | DOI Listing |
Pharmaceutics
November 2024
School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China.
: To improve the solubility and permeability of Sparfloxacin (SPX) and enhance its antimicrobial activity in vitro, two unreported pharmaceutical crystalline salts were synthesized and characterized in this paper. One is a hydrated crystal of Sparfloxacin with Pimelic acid (PIA), another is a hydrated crystal of Sparfloxacin with Azelaic acid (AZA), namely, SPX-PIA-HO (2CHFNO·CHO·2HO) and SPX-AZA-HO (4CHFNO·2CHO·5HO). : The structure and purity of two crystalline salts were analyzed using solid-state characterization methods such as single-crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and infrared spectroscopy.
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December 2024
Chemistry Department, Lomonosov Moscow State University, Leninskie Gory, 1/3, Moscow 119991, Russia.
The peculiarities of the crystal formation from supersaturated aqueous solutions of CuSO on polymer substrates were studied using X-ray diffractometry. During the crystal formation, the test solutions were irradiated with one or two counter-propagating ultrasonic beams. Test solutions were prepared using natural deionized water with a deuterium content of 157 ± 1 ppm.
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December 2024
School of Engineering, RMIT University, Melbourne, VIC 3000, Australia.
Entropy-Driven Ring-Opening Polymerisation represents an attractive mechanism to produce high-performance polymeric materials as it can be performed using neat, low-viscosity precursors and without the production of by-products or release of volatiles. Macrocyclic oligomers (MCOs) of polyether ketone ketone (PEKK) were synthesised and investigated as an method of forming this high-performance thermoplastic. Cyclic oligomers were successfully synthesised by pseudo-high dilution methods, and the reaction conditions were optimised through careful addition of starting materials and carbonate base selection.
View Article and Find Full Text PDFMicroorganisms
November 2024
Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, CA 92697, USA.
(Mtb) is the causative agent of tuberculosis, the world's deadliest infectious disease. Mtb uses a variety of mechanisms to evade the human host's defenses and survive intracellularly. Mtb's oxidative stress response enables Mtb to survive within activated macrophages, an environment with reactive oxygen species and low pH.
View Article and Find Full Text PDFMolecules
December 2024
Department of Solid State Chemistry, University of Chemistry and Technology, Prague, Technicka 5, 16628 Prague, Czech Republic.
Apremilast (APR) is an anti-inflammatory drug commonly used in the treatment of psoriasis. In efforts to enhance its solubility, several cocrystals with similar structural features have been developed. This study investigates the cocrystallization of APR with four phenolic-type coformers: phenol, catechol, pyrogallol, and hydroxyquinol.
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