Visualizing degradation of nerve agent simulants by functionalized Zr-based MOFs: from solution to hydrogels

2021 ◽  
Author(s):  
Hongyan Su ◽  
Pengcheng Huang ◽  
Fang-ying Wu

Visual monitoring of degradation of nerve agent simulants based on switchable fluorescence of UiO-66-NH2 was developed. In the hydrolysis, the decomposition products perturbed the linker-to-cluster charge transfer and stimulated the...

1976 ◽  
Vol 54 (5) ◽  
pp. 760-764 ◽  
Author(s):  
Rafik O. Loutfy ◽  
Allan C. Somersall

Non-classical energy transfer from the excited singlet states of aliphatic ketones to carbon tetrachloride leads to sensitized decomposition products and fluorescence quenching. The correlation of the ionization potentials for a wide variety of such ketones with the corresponding quenching constants from fluorescence data has been rationalized by an exciplex mechanism. The correlation implies that charge transfer from the excited ketone to the carbon tetrachloride is a major contribution to the exciplex state for which two possible structures are tentatively proposed.


Author(s):  
J. Taft∅

It is well known that for reflections corresponding to large interplanar spacings (i.e., sin θ/λ small), the electron scattering amplitude, f, is sensitive to the ionicity and to the charge distribution around the atoms. We have used this in order to obtain information about the charge distribution in FeTi, which is a candidate for storage of hydrogen. Our goal is to study the changes in electron distribution in the presence of hydrogen, and also the ionicity of hydrogen in metals, but so far our study has been limited to pure FeTi. FeTi has the CsCl structure and thus Fe and Ti scatter with a phase difference of π into the 100-ref lections. Because Fe (Z = 26) is higher in the periodic system than Ti (Z = 22), an immediate “guess” would be that Fe has a larger scattering amplitude than Ti. However, relativistic Hartree-Fock calculations show that the opposite is the case for the 100-reflection. An explanation for this may be sought in the stronger localization of the d-electrons of the first row transition elements when moving to the right in the periodic table. The tabulated difference between fTi (100) and ffe (100) is small, however, and based on the values of the scattering amplitude for isolated atoms, the kinematical intensity of the 100-reflection is only 5.10-4 of the intensity of the 200-reflection.


Author(s):  
Yimei Zhu ◽  
J. Tafto

The electron holes confined to the CuO2-plane are the charge carriers in high-temperature superconductors, and thus, the distribution of charge plays a key role in determining their superconducting properties. While it has been known for a long time that in principle, electron diffraction at low angles is very sensitive to charge transfer, we, for the first time, show that under a proper TEM imaging condition, it is possible to directly image charge in crystals with a large unit cell. We apply this new way of studying charge distribution to the technologically important Bi2Sr2Ca1Cu2O8+δ superconductors.Charged particles interact with the electrostatic potential, and thus, for small scattering angles, the incident particle sees a nuclei that is screened by the electron cloud. Hence, the scattering amplitude mainly is determined by the net charge of the ion. Comparing with the high Z neutral Bi atom, we note that the scattering amplitude of the hole or an electron is larger at small scattering angles. This is in stark contrast to the displacements which contribute negligibly to the electron diffraction pattern at small angles because of the short g-vectors.


1989 ◽  
Vol 4 ◽  
pp. 244-248 ◽  
Author(s):  
Donald L. Wolberg

The minerals pyrite and marcasite (broadly termed pyritic minerals) are iron sulfides that are common if not ubiquitous in sedimentary rocks, especially in association with organic materials (Berner, 1970). In most marine sedimentary associations, pyrite and marcasite are associated with organic sediments rich in dissolved sulfate and iron minerals. Because of the rapid consumption of sulfate in freshwater environments, however, pyrite formation is more restricted in nonmarine sediments (Berner, 1983). The origin of the sulfur in nonmarine environments must lie within pre-existing rocks or volcanic detritus; a relatively small, but significant contribution may derive from plant and animal decomposition products.


2020 ◽  
Vol 8 (40) ◽  
pp. 20963-20969 ◽  
Author(s):  
Wei Chen ◽  
Guo-Bo Huang ◽  
Hao Song ◽  
Jian Zhang

An efficient charge transfer channel for improving the photocatalytic water splitting activity and durability of CdS without sacrificial agents.


Author(s):  
Weidong Qiu ◽  
Xinyi Cai ◽  
Mengke Li ◽  
Liangying Wang ◽  
Yanmei He ◽  
...  

Dynamic adjustment of emission behaviours by controlling the extent of twisted intramolecular charge transfer character in excited state.


1997 ◽  
Vol 90 (3) ◽  
pp. 407-413
Author(s):  
MARC KELEMEN ◽  
CHRISTOPH WACHTER ◽  
HUBERT WINTER ◽  
ELMAR DORMANN ◽  
RUDOLF GOMPPER ◽  
...  

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