Mechanochromism of Piroxicam Accompanied by Intermolecular Proton Transfer Probed by Spectroscopic Methods and Solid-Phase Changes

2005 ◽  
Vol 127 (18) ◽  
pp. 6641-6651 ◽  
Author(s):  
Agam R. Sheth ◽  
Joseph W. Lubach ◽  
Eric J. Munson ◽  
Francis X. Muller ◽  
David J. W. Grant
2005 ◽  
Vol 127 (31) ◽  
pp. 10778-10779 ◽  
Author(s):  
Donatella Armentano ◽  
Giovanni De Munno ◽  
Teresa F. Mastropietro ◽  
Miguel Julve ◽  
Francesc Lloret

2017 ◽  
Vol 373 ◽  
pp. 284-287
Author(s):  
Bożena Zgardzińska ◽  
Maciej Tydda ◽  
Jan Wawryszczuk

The positron annihilation lifetime spectroscopy (PALS) was applied to investigate the properties of capsules composed of n-alkanes (filling material) and polymer (shell) in the broad range of pressures up to 450 MPa. These microcapsules aggregate into the grains having about 200 μm in diameter. Their properties were investigated as a function of pressure (p) at several selected temperatures: when the filling material is in liquid, rotator and solid phase. Pressure experiments were performed without gas access to the sample and in an argon atmosphere. Two o-Ps components were found, the longer-lived correspond to the filler material, and the shorter-lived one – to the shell. These components change with p; even a small pressure (6 MPa) reduces considerably the o-Ps lifetimes (τ). At 303 K the o-Ps lifetime in the core changes non-monotonically, and at 60 MPa τ is higher than at 20 MPa. The increase of pressure induces the phase changes in the filling material, and also produces the deformation of microcapsule aggregates and crash of small capsules at the grain boundary region. Internal structure of the microcapsules was observed by SEM.


Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 516
Author(s):  
You Qian ◽  
Fuchun Gong ◽  
Jiguang Li ◽  
Pan Ma ◽  
Hanming Zhu ◽  
...  

Constructing excited-state intermolecular proton transfer (ESIPT-e) fluorophores represents significant challenges due to the harsh requirement of bearing a proton donor-acceptor (D-A) system and their matching proton donating-accepting ability in the same molecule. Herein, we synthesized a new-type ESIPT-e fluorophor (2-APC) using the “four-component one-pot” reaction. By the installing of a cyano-group on pyridine scaffold, the proton donating ability of -NH2 was greatly enhanced, enabling 2-APC to undergo ESIPT-e process. Surprisingly, 2-APC exhibited dual-emissions in protic solvents ethanol and normal fluorescence in aprotic solvents, which is vastly different from that of conventional ESIPT-a dyes. The ESIPT emission can be obviously suppressed by Fe3+ due to the coordination reaction of Fe3+ with the A-D system in 2-APC. From this basis, a highly sensitive and selective method was established using 2-APC as a fluorescent probe, which offers the sensitive detection of Fe3+ ranging from 0 to 13 μM with the detection limit of 7.5 nM. The recovery study of spiked Fe3+ measured by the probe showed satisfactory results (97.2103.4%) with the reasonable RSD ranging from 3.1 to 3.8%. Moreover, 2-APC can also exhibit aggregation-induced effect in poor solvent or solid-state, eliciting strong red fluorescence. 2-APC was also applied to cell-imaging, exhibiting good cell-permeability, biocompatibility and color rendering. This multi-mode emission of 2-APC is significant departure from that of conventional extended p-conjugated systems and ESIPT dyes based on a flat and rigid molecular design. The “one-pot synthesis” strategy for the construction of ESIPT molecules pioneered a new route to achieve tricolor-emissive fluorophores.


2017 ◽  
Vol 106 ◽  
pp. 97-101 ◽  
Author(s):  
Anna H. Kaksonen ◽  
Silja Särkijärvi ◽  
Jaakko A. Puhakka ◽  
Esa Peuraniemi ◽  
Saku Junnikkala ◽  
...  

2005 ◽  
Vol 122 (20) ◽  
pp. 204304 ◽  
Author(s):  
Rafał A. Bachorz ◽  
Maciej Harańczyk ◽  
Iwona Dąbkowska ◽  
Janusz Rak ◽  
Maciej Gutowski

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