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The F 2 molecule is commonly described as having exactly one bond (in other words, a bond order of 1) provided by one p electron per atom, as are other halogen X 2 molecules. However, the heavier halogens' p electron orbitals partly mix with those of d orbitals, which results in an increased effective bond order; for example, chlorine has a ...
In compounds, fluorine almost exclusively assumes an oxidation state of −1. Fluorine in F 2 is defined to have oxidation state 0. The unstable species F − 2 and F − 3, which decompose at around 40 K, have intermediate oxidation states; [100] F + 4 and a few related species are predicted to be stable. [101]
Worldwide, 50 million people receive water from water supplies that naturally have close to the "optimal level". [12] In other locations the level of fluoride is very low, sometimes leading to fluoridation of public water supplies to bring the level to around 0.7–1.2 ppm. Mining can increase local fluoride levels [13]
The reaction mixture was warmed to 25°, 50 mL of water was added, and the lower organic layer was separated and dried with anhydrous magnesium sulfate and distilled to give 12.0 g (90%) of 1-fluorooctane as a colorless liquid, bp 42–43° (20 mm). 19 F NMR (CCl 3 F): -218.8 ppm (tt, 2 J = 49 Hz, 3 J = 25 Hz). [18]
Electrophilic fluorinating reagents could in principle operate by electron transfer pathways or an S N 2 attack at fluorine. This distinction has not been decided. [2] By using a charge-spin separated probe, [3] it was possible to show that the electrophilic fluorination of stilbenes with Selectfluor proceeds through an SET/fluorine atom transfer mechanism.
Fluorine gas (F 2) can act both as an electrophilic and atomic source of fluorine. [4] The weak F–F bond strength (36 kcal/mol (150 kJ/mol) [5]) allows for homolytic cleavage. The reaction of F 2 with organic compounds is, however, highly exothermic and can lead to non-selective fluorinations and C–C cleavage, as well as explosions. [6]
NiF 2 is prepared by treatment of anhydrous nickel(II) chloride with fluorine at 350 °C: [2]. NiCl 2 + F 2 → NiF 2 + Cl 2. The corresponding reaction of cobalt(II) chloride results in oxidation of the cobalt, whereas nickel remains in the +2 oxidation state after fluorination because its +3 oxidation state is less stable.
Fluorine-18 (18 F, also called radiofluorine) is a fluorine radioisotope which is an important source of positrons. It has a mass of 18.0009380(6) u and its half-life is 109.771(20) minutes. It decays by positron emission 96.7% of the time and electron capture 3.3% of the time.