9 F FLUORINE 18.998 POISON TO PROMISE Fluorine is a highly toxic diatomic pale yellow gas. Thanks to the continued creativity of countless chemists, this extremely reactive gas was eventually transformed into a more utilizable form via electrolysis. This opened the doors for further experimentation and allowed chemists to incorporate this element into different molecules not found in nature. Doing so has resulted in compounds that are highly utilized and improve our daily lives. 13 4 Fluorine’s Origin C + He 14N + 4He Fluorine is estimated to be the 24th combine to form combine to form most common element in the universe. It is so rare because it is 16 18 not a product of the usual nuclear O + neutron F sp fusion processes in stars. lits into impacts In space, fluorine commonly 14 18 s combines with hydrogen to p N O + positron lit form hydrogen fluoride. s into Fluorine cations have 14C + proton been seen in planetary proton + 18O nebulae and in stars, including our Sun. combine to 4He form 15N 4He + 15N 19F The Taming of the Fluorine Henri Moissan Henri Moissan was a brave and intelligent scientist who was awarded a Nobel Prize in 1906 for discovering a way to isolate fluorine— requiring some rather unnerving experiments that involved the electrolysis of KHF2 in neat HF (a very corrosive gas at room temperature). In the past, all attempts to isolate this element failed by other experimenters, some of which resulted in death. Fluorine is the most electronegative F element with a value of 3.98 on the Pauling electronegativity scale. Given that fluorine is one electron away from having a fully filled 2p electron orbital, and its relatively small size, the electrons are held very tightly to the nucleus, contributing to Henri Moissan its high electronegativity. 1852-1907 Uses of Fluorine Toothpaste Fluoride toothpastes make up more than 95% of all toothpaste sales. Enhanced rocket fuel Most liquid chemical rockets use two separate propellants: a fuel and an oxidizer. Oxidizers include nitric acid, nitrogen tetroxide, liquid oxygen, and liquid fluorine. Pharmaceuticals Among the currently approved FDA pharmaceutical drugs, nearly one- third contain fluorine (this was a mere 2% in 1970), many of which are top- selling pharmaceuticals (e.g. Lipitor). Fluorine can impart many unique (and still unpredictable) chemical properties when attached to organic compounds of biological relevance. To name a few: increased lipophilicity, metabolic stability, and potency. Given fluorine’s wide range of properties it has brought many attractive opportunities in drug design. Refrigerators Fluorine is present in Freon which is used to keep refrigerators cold. Polytetrafluoroethylene (Teflon) Polytetrafluoroethylene (PTFE) is a fluorocarbon polymer that was discovered in 1938 by accident when a chemist was attempting to make a chlorofluorocarbon refrigerant. A few applications include non-stick coating to frying pans, wiring (e.g coaxial cables), and Gore-Tex. Find out what Reaxys can do for you: https://www.elsevier.com/solutions/reaxys Follow Reaxys for all the latest news and information: @elsevier.reaxys @Reaxys /company/reaxys 9 F FLUORINE 18.998 POISON TO PROMISE Fluorine is a highly toxic diatomic pale yellow gas. Thanks to the continued creativity of countless chemists, this extremely reactive gas was eventually transformed into a more utilizable form via electrolysis. This opened the doors for further experimentation and allowed chemists to incorporate this element into different molecules not found in nature. Doing so has resulted in compounds that are highly utilized and improve our daily lives. Fluorine’s Origin Fluorine is estimated to be the 24th most common element in the universe. It is so rare because it is not a product of the usual nuclear fusion processes in stars. In space, fluorine commonly combines with hydrogen to form hydrogen fluoride. Fluorine cations have been seen in planetary nebulae and in stars, including our Sun. 13C + 4He 14N + 4He combine to form combine to form 16O + neutron 18 s F pl to its in impacts 14 N s 18 p o lits int O + positron 14C + proton proton + 18O combine to form 15N 4He 4He + 15N 19F The Taming of the Fluorine F Henri Moissan 1852-1907 Henri Moissan Henri Moissan was a brave and intelligent scientist who was awarded a Nobel Prize in 1906 for discovering a way to isolate fluorine—requiring some rather unnerving experiments that involved the electrolysis of KHF2 in neat HF (a very corrosive gas at room temperature). In the past, all attempts to isolate this element failed by other experimenters, some of which resulted in death. Fluorine is the most electronegative element with a value of 3.98 on the Pauling electronegativity scale. Given that fluorine is one electron away from having a fully filled 2p electron orbital, and its relatively small size, the electrons are held very tightly to the nucleus, contributing to its high electronegativity. Uses of Fluorine Toothpaste Fluoride toothpastes make up more than 95% of all toothpaste sales. Enhanced rocket fuel Most liquid chemical rockets use two separate propellants: a fuel and an oxidizer. Oxidizers include nitric acid, nitrogen tetroxide, liquid oxygen, and liquid fluorine. Pharmaceuticals Among the currently approved FDA pharmaceutical drugs, nearly one-third contain fluorine (this was a mere 2% in 1970), many of which are top- selling pharmaceuticals (e.g. Lipitor). Fluorine can impart many unique (and still unpredictable) chemical properties when attached to organic compounds of biological relevance. To name a few: increased lipophilicity, metabolic stability, and potency. Given fluorine’s wide range of properties it has brought many attractive opportunities in drug design. Refrigerators Fluorine is present in Freon which is used to keep refrigerators cold. Polytetrafluoroethylene (Teflon) Polytetrafluoroethylene (PTFE) is a fluorocarbon polymer that was discovered in 1938 by accident when a chemist was attempting to make a chlorofluorocarbon refrigerant. A few applications include non-stick coating to frying pans, wiring (e.g coaxial cables), and Gore-Tex. Find out what Reaxys can do for you: https://www.elsevier.com/solutions/reaxys Follow Reaxys for all the latest news and information: @elsevier.reaxys @Reaxys /company/reaxys.