A smart post-synthetic route towards [Fe2Co2] molecular capsules with electron transfer and bidirectional switching behaviors

Author(s):  
Lingyi Meng ◽  
Yi-Fei Deng ◽  
Shihao Liu ◽  
Zhiping Zheng ◽  
Yuan-Zhu Zhang
Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3337
Author(s):  
He Yin ◽  
Min Wang ◽  
Loon-Seng Tan ◽  
Long Y. Chiang

New 3D conformers were synthesized to show a nanomolecular configuration with geometrically branched 2-diphenylaminofluorene (DPAF-C2M) chromophores using a symmetrical 1,3,5-triaminobenzene ring as the center core for the connection of three fused DPAF-C2M moieties. The design led to a class of cis-cup-tris[(DPAF-C2M)-C60(>DPAF-C9)] 3D conformers with three bisadduct-analogous <C60> cages per nanomolecule facing at the same side of the geometrical molecular cis-cup-shape structure. A sequential synthetic route was described to afford this 3D configurated conformer in a high yield with various spectroscopic characterizations. In principle, a nanostructure with a non-coplanar 3D configuration in design should minimize the direct contact or π-stacking of fluorene rings with each other during molecular packing to the formation of fullerosome array. It may also prevent the self-quenching effect of its photoexcited states in solids. Photophysical properties of this cis-cup-conformer were also investigated.


2015 ◽  
Vol 68 (3) ◽  
pp. 500 ◽  
Author(s):  
Anthony A. Provatas ◽  
Gary A. Epling ◽  
James D. Stuart ◽  
Aliaksandr Yeudakimau

The regioselective cleavage of epoxides using visible light and a catalytic dye is reported in this study as an alternative mild synthetic approach. The epoxide radical anion is generated via visible light in an electron transfer reaction, induced by non-toxic dyes, leading to ring opening and formation of the corresponding alcohol with the hydroxyl group on the less substituted carbon in excellent yields.


e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexander Tolstov ◽  
Daniel Gromadzki ◽  
Miloš Netopilík ◽  
Ričardas Makuška

AbstractAnionic comb polyelectrolytes containing 2-acrylamido-2-methyl-Npropane sulfonate groups both in the mainchain and in the grafts were prepared by activators generated by electron transfer atom transfer radical polymerization (AGET ATRP). The synthetic route included AGET ATRP copolymerization of 2- acrylamido-2-methyl-N-propanesulfonic acid (AMPS) and 2-hydroxyethyl acrylate (HEA) followed by modification of HEA units in the copolymers by 2- bromoisobutyryl bromide yielding macroinitiators which served for “grafting from” AGET ATRP of AMPS. Composition of the final and intermediate products was determined by 1H-NMR spectroscopy, and molecular weight and polydispersity of the resulting polyelectrolytes were estimated by size exclusion chromatography (SEC). Anionic comb polyelectrolytes with relatively low density of the grafts (5 - 7 grafting sites per 100 monomeric units of the mainchain) and relatively short side chains (9 or 25 AMPS units) were synthesized and characterized.


Author(s):  
P. Bonhomme ◽  
A. Beorchia

We have already described (1.2.3) a device using a pockel's effect light valve as a microscopical electron image converter. This converter can be read out with incoherent or coherent light. In the last case we can set in line with the converter an optical diffractometer. Now, electron microscopy developments have pointed out different advantages of diffractometry. Indeed diffractogram of an image of a thin amorphous part of a specimen gives information about electron transfer function and a single look at a diffractogram informs on focus, drift, residual astigmatism, and after standardizing, on periods resolved (4.5.6). These informations are obvious from diffractogram but are usualy obtained from a micrograph, so that a correction of electron microscope parameters cannot be realized before recording the micrograph. Diffractometer allows also processing of images by setting spatial filters in diffractogram plane (7) or by reconstruction of Fraunhofer image (8). Using Electrotitus read out with coherent light and fitted to a diffractometer; all these possibilities may be realized in pseudoreal time, so that working parameters may be optimally adjusted before recording a micrograph or before processing an image.


2004 ◽  
Vol 71 ◽  
pp. 1-14
Author(s):  
David Leys ◽  
Jaswir Basran ◽  
François Talfournier ◽  
Kamaldeep K. Chohan ◽  
Andrew W. Munro ◽  
...  

TMADH (trimethylamine dehydrogenase) is a complex iron-sulphur flavoprotein that forms a soluble electron-transfer complex with ETF (electron-transferring flavoprotein). The mechanism of electron transfer between TMADH and ETF has been studied using stopped-flow kinetic and mutagenesis methods, and more recently by X-ray crystallography. Potentiometric methods have also been used to identify key residues involved in the stabilization of the flavin radical semiquinone species in ETF. These studies have demonstrated a key role for 'conformational sampling' in the electron-transfer complex, facilitated by two-site contact of ETF with TMADH. Exploration of three-dimensional space in the complex allows the FAD of ETF to find conformations compatible with enhanced electronic coupling with the 4Fe-4S centre of TMADH. This mechanism of electron transfer provides for a more robust and accessible design principle for interprotein electron transfer compared with simpler models that invoke the collision of redox partners followed by electron transfer. The structure of the TMADH-ETF complex confirms the role of key residues in electron transfer and molecular assembly, originally suggested from detailed kinetic studies in wild-type and mutant complexes, and from molecular modelling.


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