Quality Control of Sodium chlorideIn 2020 ,《Single-molecule tautomerization tracking through space- and time-resolved fluorescence spectroscopy》 was published in Nature Nanotechnology. The article was written by Doppagne, Benjamin; Neuman, Tomas; Soria-Martinez, Ruben; Lopez, Luis E. Parra; Bulou, Herve; Romeo, Michelangelo; Berciaud, Stephane; Scheurer, Fabrice; Aizpurua, Javier; Schull, Guillaume. The article contains the following contents:
Tautomerization, the interconversion between two constitutional mol. isomers, is ubiquitous in nature, plays a major role in chem. and is perceived as an ideal switch function for emerging mol.-scale devices. Within free-base porphyrin, porphycene or phthalocyanine, this process involves the concerted or sequential hopping of the two inner hydrogen atoms between equivalent nitrogen sites of the mol. cavity. Electronic and vibronic changes that result from this NH tautomerization, as well as details of the switching mechanism, were extensively studied with optical spectroscopies, even with single-mol. sensitivity. The influence of at.-scale variations of the mol. environment and submol. spatial resolution of the tautomerization could only be investigated using scanning probe microscopes, at the expense of detailed information provided by optical spectroscopies. Here, we combine these two approaches, scanning tunnelling microscopy (STM) and fluorescence spectroscopy, to study the tautomerization within individual free-base phthalocyanine (H2Pc) mols. deposited on a NaCl-covered Ag(111) single-crystal surface. STM-induced fluorescence (STM-F) spectra exhibit duplicate features that we assign to the emission of the two mol. tautomers. We support this interpretation by comparing hyper-resolved fluorescence maps(HRFMs) of the different spectral contributions with simulations that account for the interaction between mol. excitons and picocavity plasmons. We identify the orientation of the mol. optical dipoles, determine the vibronic fingerprint of the tautomers and probe the influence of minute changes in their at.-scale environment. Time-correlated fluorescence measurements allow us to monitor the tautomerization events and to associate the proton dynamics to a switching two-level system. Finally, optical spectra acquired with the tip located at a nanometer-scale distance from the mol. show that the tautomerization reaction occurs even when the tunnelling current does not pass through the mol. Together with other observations, this remote excitation indicates that the excited state of the mol. is involved in the tautomerization reaction path. The experimental part of the paper was very detailed, including the reaction process of Sodium chloride(cas: 7647-14-5Quality Control of Sodium chloride)
Sodium chloride(cas: 7647-14-5) has been used for the preparation of tris buffered saline, phosphate buffered saline, MPM-2 (mitotic protein monoclonal 2) cell lysis buffer, immunoprecipitation wash buffer, LB (Luria-Bertani) media and dialysis buffer.Quality Control of Sodium chloride
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics