Recent advances in the preparation of semifluorinated polymers

2021 ◽  
Author(s):  
Joseph A. Jaye ◽  
Ellen M. Sletten
Keyword(s):  
Side Chains ◽  
Recent Advances ◽  
Semifluorinated Polymers

Synthesis of semifluorinated polymers containing fluorous groups on the backbone or as side chains is an increasingly popular field of research.

scholarly journals Recent Advances in Conjugated Graft Copolymers: Approaches and Applications

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 3019 ◽  
Author(s):  
Tomasz Jarosz ◽  
Karolina Gebka ◽  
Agnieszka Stolarczyk
Keyword(s):  
Recent Progress ◽  
Main Chain ◽  
Graft Copolymers ◽  
Side Chains ◽  
Recent Advances

The main goal of this mini review is to summarise the most recent progress in the field of conjugated graft copolymers featuring conjugation across the main chain, across side chains or across both. The main approaches to the synthesis of conjugated graft copolymers are highlighted, and the various trends in the development of new copolymer materials and the intended directions of their applications are explored.

Self-Organization in Semifluorinated Polymers

2004 ◽  
Vol 443-444 ◽  
pp. 223-226 ◽  
Author(s):  
D. Jehnichen ◽  
D. Pospiech ◽  
L. Häußler ◽  
P. Friedel ◽  
A. Gottwald ◽  
...  
Keyword(s):  
Surface Segregation ◽  
Microphase Separation ◽  
Side Chains ◽  
Temperature Dependent ◽  
Heating And Cooling ◽  
Dsc Measurements ◽  
X Ray Scattering ◽  
Expansion Coefficients ◽  
Bulk Structure ◽  
Semifluorinated Polymers

Alkyl-perfluoroalkyl compounds are known to form a microphase-separated structure due to the thermodynamic immiscibility between the fluorinated and the protonated segments [1,2]. Many similarities between bulk and surface structures of such polymers were found in the past [2,3,4] which can be explained by both microphase separation in the bulk as well as surface segregation of the fluorinated parts. Basing on this concept, polymers with chemically different main chains were attached with alkylperfluoroalkyl side chains (particularly, oxydecylperfluorodecyl chains, -O-(CH2) 10-(CF 2) 9-CF 3). Combined investigations by means of temperature-dependent X-ray scattering, molecular modeling and DSC measurements were performed to characterize the bulk structure in dependence on the flexibility of the main chain as well as the density of side chains. The polymers under investigation show one or more phase transitions in the temperature range from room temperature to 300 °C which can be assigned as transitions between different smectic structures. These phases are characterized to have positive as well as negative expansion coefficients, respectively, indicating changes of the tilt angle of the side chains and/or the degree of interdigitation. The polymer melts feature a high memory behavior evidenced by reversed imaging of the scattering patterns in the heating and cooling runs.

scholarly journals Recent Advances in the Stereoselective Total Synthesis of Natural Pyranones Having Long Side Chains

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1905
Author(s):  
Satya Kumar Avula ◽  
Biswanath Das ◽  
Rene Csuk ◽  
Ahmed Al-Rawahi ◽  
Ahmed Al-Harrasi
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Present Article ◽  
Structural Features ◽  
Side Chains ◽  
Total Syntheses ◽  
Recent Advances ◽  
Long Chain

Pyranone natural products have attracted great attention in recent years from chemists and biologists due to their fascinating stereoisomeric structural features and impressive bioactivities. A large number of stereoselective total syntheses of these compounds have been described in the literature. The natural pyranones with long side chains have recently received significant importance in the synthetic field. In the present article, we aim to review the modern progress of the stereoselective total syntheses of these natural pyranones containing long-chain substituents.

Recent Advances in the Synthesis and Transformations of Heterocycles Mediated by Fluoride Ion Activated Silanes

2014 ◽  
Vol 52 (1-2) ◽  
pp. 3-17
Author(s):  
E. Ābele
Keyword(s):  
Heterocyclic Compounds ◽  
Fluoride Ion ◽  
Side Chains ◽  
Recent Advances

Abstract Modern methodologies that use silanes in the presence of fluoride ion for the preparation and transformation of three-, four-, five-, six-, and seven-membered heterocycles have been reviewed, covering literature from January 2010 to December 2012. Characteristic reactions in side chains of heterocyclic compounds are presented

Recent Advances in High Dispersion Spectroscopy of Globular Cluster Stars

1988 ◽  
Vol 132 ◽  
pp. 525-530
Author(s):  
Raffaele G. Gratton
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
High Dispersion ◽  
Photographic Material ◽  
Recent Advances ◽  
Metal Abundances ◽  
Ccd Detectors ◽  
Major Progress

The use CCD detectors has allowed a major progress in abundance derivations for globular cluster stars in the last years. Abundances deduced from high dispersion spectra now correlates well with other abundance indicators. I discuss some problems concerning the derivation of accurate metal abundances for globular clusters using high dispersion spectra from both the old photographic and the most recent CCD data. The discrepant low abundances found by Cohen (1980), from photographic material for M71 giants, are found to be due to the use of too high microturbulences.

Chelation-assisted transition metal-catalysed C–H chalcogenylations

2020 ◽  
Vol 7 (8) ◽  
pp. 1022-1060 ◽  
Author(s):  
Wenbo Ma ◽  
Nikolaos Kaplaneris ◽  
Xinyue Fang ◽  
Linghui Gu ◽  
Ruhuai Mei ◽  
...  
Keyword(s):  
Transition Metal ◽  
Recent Advances ◽  
Site Selectivity ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

This review summarizes recent advances in C–S and C–Se formations via transition metal-catalyzed C–H functionalization utilizing directing groups to control the site-selectivity.

Nucleosome dynamics

2006 ◽  
Vol 73 ◽  
pp. 109-119 ◽  
Author(s):  
Chris Stockdale ◽  
Michael Bruno ◽  
Helder Ferreira ◽  
Elisa Garcia-Wilson ◽  
Nicola Wiechens ◽  
...  
Keyword(s):  
High Resolution ◽  
Chromatin Structure ◽  
Current Knowledge ◽  
Dynamic Properties ◽  
Structure And Dynamics ◽  
Nucleosome Dynamics ◽  
Sharp Focus ◽  
Recent Advances ◽  
Insight Into ◽  
Chromatin Structure And Dynamics

In the 30 years since the discovery of the nucleosome, our picture of it has come into sharp focus. The recent high-resolution structures have provided a wealth of insight into the function of the nucleosome, but they are inherently static. Our current knowledge of how nucleosomes can be reconfigured dynamically is at a much earlier stage. Here, recent advances in the understanding of chromatin structure and dynamics are highlighted. The ways in which different modes of nucleosome reconfiguration are likely to influence each other are discussed, and some of the factors likely to regulate the dynamic properties of nucleosomes are considered.

Recent Advances in the Treatment of Pulmonary Tuberculosis

1950 ◽  
Vol 34 (5) ◽  
pp. 1363-1380
Author(s):  
Theodore L. Badger ◽  
William E. Patton
Keyword(s):  
Pulmonary Tuberculosis ◽  
Recent Advances
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