Английская Википедия:Hexafluorothioacetone
Шаблон:Chembox Hexafluorothioacetone is an organic perfluoro thione compound with formula CF3CSCF3. At standard conditions it is a blue gas.[1]
Production
Hexafluorothioacetone was first produced by Middleton in 1961 by boiling bis-(perfluoroisopropyl)mercury with sulfur.
Properties
Hexafluorothioacetone boils at 8 °C.[2] Below this it is a blue liquid.[1]
Colour
The blue colour is due to absorption in the visible light range with bands at 800–675 nm and 725–400 nm. These bands are due to T1–S0 and S1–S0 transitions.[1] There is also a strong absorption in ultraviolet around 230-190 nm.[1]
Reactions
Hexafluorothioacetone acts more like a true thiocarbonyl (C=S) than many other thiocarbonyl compounds, because it is not able to form thioenol compounds (=C-S-H), and the sulfur is not in a negative ionized state (C-S−).[3] Hexafluorothioacetone is not attacked by water or oxygen at standard conditions as are many other thiocarbonyls.[1]
Bases trigger the formation of a dimer 2,2,4,4-tetrakis-(trifluoromethyl)-1,3-dithietane.[1] Bases includes amines.[3]
The dimer can be heated to regenerate the hexafluorothioacetone monomer.[1]
The dimer is also produced in a reaction with hexafluoropropene and sulfur with some potassium fluoride.[1][4]
Hexafluorothioacetone reacts with bisulfite to form a Bunte salt CH(CF3)2SSO2−.[3]
Mercaptans reacting with hexafluorothioacetone yield disulfides or a thiohemiketal:
- R-SH + C(CF3)2S → R-S-S-CH(CF3)2.[3]
- R-SH + C(CF3)2S → RSC(CF3)2SH (for example in methyl mercaptan or ethyl mercaptan).[3]
With mercaptoacetic acid, instead of a thiohemiketal, water elimination yields a ring shaped molecule called a dithiolanone -CH2C(O)SC(CF3)2S- (2,2-di(trifluoromethyl)-1,3-dithiolan-4-one).[3] Aqueous hydrogen chloride results in the formation of a dimeric disulfide CH(CF3)2SSC(CF3)2Cl.[3] Hydrogen bromide with water yields the similar CH(CF3)2SSC(CF3)2Br.[3] Dry hydrogen iodide does something different and reduces the sulfur making CH(CF3)2SH. Wet hydrogen iodide only reduces to a disulfide CH(CF3)2SSC(CF3)2H. Strong organic acids add water to yield a disulfide compound CH(CF3)2SSC(CF3)2OH.[3]
Chlorine and bromine add to hexafluorothioacetone to make CCl(CF3)2SCl and CBr(CF3)2SBr.[3]
With diazomethane hexafluorothioacetone produces 2,2,5,5-tetrakis(trifluoromethyl)-l,3-dithiolane, another substituted dithiolane.[3] Diphenyldiazoniethane reacts to form a three membered ring called a thiirane (di-2,2-trifluoromethyl-di-3,3-phenyl-thiirane)
Trialkylphosphites (P(OR)3) react to make a trialkoxybis(trifluoromethyl)methylenephosphorane (RO)3P=C(CF3)2 and a thiophosphite (RO)3PS.[3]
Hexafluorothioacetone can act as a ligand on nickel.[5]
Hexafluorothioacetone is highly reactive to alkenes and dienes combining via addition reactions. With butadiene it reacts even as low as -78 °C to yield 2,2-bis-(trifluoromethyl)-3,6-dihydro-2H-l-thiapyran.[6]
See also
References
External links
