Thomas R. Bierschenk

Liquid-phase fluorination

This invention pertains to a method for liquid phase fluorination for perfluorination of a wide variety of hydrogen-containing compounds.

The generality of metal atom-free radical reactions and synthesis of new trifluoromethylalkyls of gold (III) and silver

Abstract The cocondensation reaction of trifluoromethyl radicals with gold and silver vapors is an effective and efficient synthesis for the new compounds, Au(CF 3 ) 3 and AgCF 3 . Addition of trimethylphosphine to these alkyls yielded the room temperature stable compounds, Au(CF 3 ) 3 PMe 3 and AgCF 3 (PMe 3 ).

Metal vapor synthesis of trifluoromethyl-Group III compounds

Abstract Tris(trifluoromethyl)thallium, Tl(CF3)3, as well as other less defined trifluoromethyl-Group III compounds have been prepared for the first time by condensing metal atoms with trifluoromethyl radicals on a cryogenic surface. The unusually reactive nature of several of the products necessitated that a very unique and elaborate metal-atom reactor be designed and constructed which would allow the isolation of the products at sub-ambient conditions.

Synthesis of transition metal alkyls and σbonded metal compounds by the cocondensation of metal vapor and free radicals: A general synthetic technique

Abstract The study of σbonded metal compounds has received much attention in the past several years. A problem which has hindered this study has been the unsuccessful preparation of some metal alkyls. Reaction conditions are often such that a slightly stable metal alkyl compound is decomposed by the reaction conditions or the reactants themselves. An idea which shows promise for such syntheses is the cocondensation of metal vapor with radical species on cryogenic surfaces: Using this technique, novel electron deficient metal akyls of marginal thermal stability such as Cd(CF 3 ) 2 , Pd(CF 3 ) 2 , Ni(CF 3 ) 2 , Co(SiF 3 ) 2 , Pd(SiF 3 ) 2 , and Ni(SiF 3 ) 2 have been prepared. Complexation of these unstable compounds with phosphine or with arenes gives stable, albeit reactive species such as Ni(CF 3 ) 2 (PMe 3 ) 2 , Pd(CF 3 ) 2 (PMe 3 ) 2 , (n 6 -toluene)Ni(SiF 3 ) 2 , and (n 6 -mesitylene)Co(SiF 3 ) 2 . The radicals, such as ·CF 3 and ·SiF 3 are produced in a low temperature glow discharge of a symmetrical gas having a weak central bond (i.e., C 2 F 6 and Si 2 F 6 ). We have found that many radicals can be cleanly generated in this manner such as ·CH 3 , ·NF 2 , ·PF 2 , ·SH 3 , ·SCF 3 , ·OCF 3 , and ·C(CF 3 ) 3 . Characterization of the products and future applications of this technique will be discussed.