Explores the preparation of dammarenediols via an efficient nonenzymatic biomimetic polyene tetracyclization route. Flourine atom as a cation-stabilizing auxiliary in biomimetic polyene cyclizations or ring formations; Lithium-halogen exchange; Trans-anti-trans-anti-trans ring stereochemistry of the d...
ChemInform Abstract: Cation‐Stabilizing Auxiliaries in Polyene Cyclizations. Part 7. The Fluorine Atom as a Cation‐Stabilizing Auxiliary in Biomimetic Polyene Cyclizations. Part 4. Total Synthesis of dl‐β‐Amyrin.doi:10.1002/chin.199322111
On the molecular level, the strength of the C-F bond is the key to these performance advantages and result in the widespread use of fluoropolymers used in producing chemically resistant gaskets, such as polytetrafluoroethylene (PTFE) and fluoroelastomers. In an examp...
Because the fluorine atom has only nine electrons, which are close to the nucleus, thepositive nucleus has a strong tendency to gain electrons to complete its outer shell. As a gasits density (specific gravity) is 1.695, and as a liquid, its density is 1.108. Its freezing point is–219.61...
When a fluorine atom is placed near the edge, the fluorine atom should be more subject to the inter-atomic potential as compared with the fluorine atom located in the interior region. Thus, it is easy to form an F2 dimer near the edge with a spin singlet. In the case of C24H12 this...
Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the right of the element's name is the mass number. The mass number represents the number of protons plus neutrons in the nucleus of an atom of the element...
Adding chemistry's most electronegative atom to porous polymer networks may lead to gas-specific filters capable of flexible ‘breathing’. The tunable activity of metal–organic frameworks towards specific guest molecules, such as drugs or pollutants, has led to a flurry of recent research reports....
Fluorine is substituted for other halogen atoms on the 1- carbon atom of a compound which contains a 1,1,1-trihalomethyl group (trichloromethyl) by contacting said compound or a precursor thereof with liquid HF in the presence of a mixture of antimony pentahalide with a least an ...
As we approach the millennium, it is inspiring and appropriate to review the applications of inorganicfluorine compoundsand their impact on our modern life. Fluorine as an element does not exist alone in nature. The abundance of this unique element in thecontinental crustis 0.065% and 0.1% in ...
A fluorine atom has discriminating characteristics, the highest electronegativity and small electric polarizability, which causes the development of a variety of unique characteristics, such as low boiling point, fluorous phase, selective gas absorbability, hydrophobicity and high chemical stability, in ...