1158433-95-4Relevant articles and documents
The fluorinated lithiumalkoxide LiORF (RF = C(CF 3)2Mes), the alcohol RFOH and Attempts to use them as precursors for new weakly coordinating anions (WCAs)
Mueller, Lutz O.,Scopelitti, Rosario,Krossinga, Ingo
, p. 1035 - 1040 (2008)
The Li alkoxides [LiORF]4 (1), [LiOR F]4[LiF]2 (2) and the solvent coordinated Li-gallate Li(C2H4Cl2)[Ga(ORF) 2(Br)2] (RF = C(CF3)2Mes) (3) were prepared by reacting a stoichiometric amount of Mes-Li · OEt2 and gaseous (CF3)2CO giving 1. Subsequently, 2 was formed in 28 % yield in a poorly understood sequence by addition of AlBr3 to 1. Upon addition of GaBr3 to four equivalents of 1 compound 3 formed. The Li alkoxide 1 forms a puckered eight membered (Li-O)4 ring and compound 2 forms an almost ideal double heterocubane with a complexed Li2F2 four membered ring in the center. The Li-gallate 3 contains the tetrahedral anion [Br 2Ga(ORF)2]- and coordinates a Li(Cl2C2H4)+ cation by two contacts to the oxygen atoms of the alkoxide. The latter describes the first account of a Li-chloroalkane complex. 1 to 3 were characterized by multinuclear NMR, IR and Raman spectroscopy as well as by their single-crystal X-ray structures. It appears that the steric bulk of the ORF alkoxide is too large to allow for the desired synthesis of the weakly coordinating anions [M(OR F)4]- (M = Al, Ga). In agreement with this, the also prepared new fluorinated alcohol HO-RF did neither react with LiAlH4 (various solvents) nor could electrochemically be reduced with H2 formation (CV).
