Novel Strong Boron-Containing Acids, The Preparation And Use Thereof

Abstract

The invention relates to boron-containing acids of the general formula (I) [B(R F ) 4-x-y (CN) x F y ] − H + (I), where x=0, 1, 2, 3 or 4, y=0, 1, 2 or 3 x+y≦4, and in which the ligands R F may be identical or different and R F stands for a perfluorinated or partially fluorinated C 1-12 -alkyl group and where the CN group is bonded to the B atom via the C atom, and complexes thereof with a solvent, to salts comprising a cation and the anion of a selection of the acids according to the invention, and to processes for the preparation of the salts.

1 . Acids of the general formula (I)  
       [B(R F ) 4-x-y (CN) x F y ] −  H +   (I)  where    x=0, 1, 2, 3 or 4,    y=0, 1, 2 or 3 and    x+y≦4,    and in which    the ligands R F  may be identical or different and    R F  stands for a perfluorinated or partially fluorinated C 1-12 -alkyl group and where    the CN group is bonded to the B atom via the C atom,    and complexes thereof with a solvent.    
   
   
       2 . Acid according to  claim 1 , characterised in that R F  stands for a perfluorinated C 1-4 -alkyl group.  
   
   
       3 . Acid according to  claim 1 , characterised in that y=0.  
   
   
       4 . Acid according to  claim 1  tetracyanoboric acid monohydrate, [B(CN) 4 ] −  H + *H 2 O, tris(trifluoromethyl)cyanoboric acid, [(CF 3 ) 3 BCN] −  H + , tris(trifluoromethyl)cyanoboric acid diethyl etherate, [(CF 3 ) 3 BCN] −  H + *(C 2 H 5 ) 2 O or tetrakis(trifluoromethyl)boric acid bis(diethyl etherate), [B(CF 3 ) 4 ] −  H + *2 (C 2 H 5 ) 2 O.  
   
   
       5 . Salts of the general formula (II)  
       [B(R F ) 4-x-y (CN) x F y ] a   −  M a+   (II)  where    x=1, 2 or 3,    y=0 or 1,    x+y≦4    a=1 or 2,    and in which    the ligands R F  may be identical or different and R F  stands for a perfluorinated or partially fluorinated C 1-12 -alkyl group and where the CN group is bonded to the B atom via the C atom and    M a+  is an alkali metal cation, a silver, magnesium, copper(I), copper(II), zinc(II) or calcium(II) cation or an organic cation, with the exception of K[B(CF 3 ) 3 CN] and [NH 4 ][B(CF 3 ) 3 CN].    
   
   
       6 . Salt of the formula (II) according to  claim 5 , characterised in that M a+  is an alkali metal cation.  
   
   
       7 . Salt of the formula (II) according to  claim 5 , characterised in that M a+  is an organic cation which is selected from the group [NR 1 R 2 R 3 R 4 ] + , [PR 1 R 2 R 3 R 4 ] + , [P(NR 1 R 2 ) 2 (NR 3 R 4 ) 2 ] + , [C(NR 1 R 2 )(NR 3 R 4 )(NR 5 R 6 )] + , [(R 1 R 2 N)—C(═OR 7 )(NR 3 R 4 )] +  or [(R 1 R 2 N)—C(═SR 7 )(NR 3 R 4 )] + , in which 
 R 1  to R 7  each, independently of one another, denotes    hydrogen,    straight-chain or branched alkyl having 1 to 20 C atoms,    straight-chain or branched alkenyl having 2-20 C atoms and one or more double bonds,    straight-chain or branched alkynyl having 2-20 C atoms and one or more triple bonds,    saturated, partially or fully unsaturated cycloalkyl having 3-7 C atoms, which may be substituted by alkyl groups having 1-6 C atoms,    where one or more of the substituents R 1  to R 7  may be partially or fully substituted by halogens, in particular —F and/or —Cl, or partially by —CN or —NO 2  and where, in the substituents R 1  to R 6 , one or two non-adjacent carbon atoms which are not in the α-position may be replaced by atoms and/or atom groups selected from the group —O—, —C(O)—, —C(O)O—, —S—, —S(O)—, —SO 2 —, —SO 2 O—, —C(O)NH—, —C(O)NR′—, —SO 2 NH—, —SO 2 NR′—, —N═, —N═N—, —NH—, —NR′—, —PR′—, —P(O)R′—, —P(O)R′—O—, —O—P(O)R′—O—, —P(O)(NR′ 2 )—NR′— and —PR′ 2 ═N— or by the end groups —C(O)X′ or —SO 2 X′, where R′=non-, partially or perfluorinated C 1 — to C 6 -alkyl, C 3 — to C 7 -cycloalkyl, unsubstituted or substituted phenyl or an unsubstituted or substituted heterocycle, and X′═F, Cl or Br.    
   
   
       8 . Salt of the formula (II) according to  claim 5 , characterised in that the organic cation in M a+  is a heterocyclic cation which is selected from the group  
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       where the substituents  
       R 1 ′ to R 4 ′ each, independently of one another, denotes  
       hydrogen,  
       straight-chain or branched alkyl having 1-20 C atoms,  
       straight-chain or branched alkenyl having 2-20 C atoms and one or more double bonds,  
       straight-chain or branched alkynyl having 2-20 C atoms and one or more triple bonds,  
       saturated, partially or fully unsaturated cycloalkyl having 3-7 C atoms, which may be substituted by alkyl groups having 1-6 C atoms,  
       saturated, partially or fully unsaturated heteroaryl,  
       heteroaryl-C 1 -C 6 -alkyl or aryl-C 1 -C 6 -alkyl,  
       where one or more substituents R 1 ′ to R 4 ′ may be partially or fully substituted by halogens, in particular —F and/or —Cl, or partially by —CN or —NO 2 , where R 1 ′ and R 4 ′ cannot simultaneously be perfluorinated or perchlorinated  
       and where, in the substituents R 1 ′ to R 4 ′, one or two non-adjacent carbon atoms which are not in the α-position to the heteroatom may be replaced by atoms and/or atom groups selected from the group —O—, —C(O)—, —C(O)O—, —S—, —S(O)—, —SO 2 —, —SO 2 O—, —C(O)NH—, —C(O)NR′—, —SO 2 NH—, —SO 2 NR′—, —N═, —N═N—, —NH—, —NR′—, —PR′—, —P(O)R′—, —P(O)R′—O—, —O—P(O)R′—O—, —P(O)(NR′ 2 )—NR′— and —PR′ 2 ═N— or by the end groups —C(O)X′ or —SO 2 X′, where R′=non-, partially or perfluorinated C 1 —to C 6 -alkyl, C 3 — to C 7 -cycloalkyl, unsubstituted or substituted phenyl or an unsubstituted or substituted heterocycle, and X′═F, Cl or Br.  
     
   
   
       9 . Process for the preparation of a salt of the formula (II) according to  claim 5  in a salt-exchange reaction, characterised in that an alkali metal salt of the formula (II) according to  claim 6  is reacted with a compound of the formula (III)  
       MA   (III),  where    M denotes a silver, magnesium, copper(I), copper(II), zinc(II) or calcium(II) cation or an organic cation and    A denotes OH − , F − , Cl − , Br − , I − , [HF 2 ] − , [CN] − , [SCN] − , [CH 3 COO] − , [CH 3 SO 3 ] − , [CF 3 COO] − , [CF 3 SO 3 ] − , [CH 3 OSO 3 ] − , [BF 4 ] − , [SO 4 ] 2− , [NO 3 ] − , [C 2 H 5 OSO 3 ] − , [(C 2 F 5 ) 2 P(O)O] − , [C 2 F 5 P(O)O 2 ] 2− , tosylates, malonates, substituted malonates or [CO 3 ] 2− .    
   
   
       10 . Use of a salt according to  claim 5  as catalyst, phase-transfer catalyst, solvent, ionic liquid or as conductive salt in the electrolytes of electrochemical devices.  
   
   
       11 . Use of an acid of the formula (I) or of a salt of the general formula (II) according to  claim 5  for the synthesis of catalysts.  
   
   
       12 . Rh catalyst of the formula (IV)  
       [(C 6 H 5 ) 3 P] 3 Rh[B(R F ) 4-x-y (CN) x F y ]  (IV),  where    x=1, 2 or 3,    y=0 or 1,    x+y≦4    and in which    the ligands R F  may be identical or different and R F  stands for a perfluorinated or partially fluorinated C 1-12 -alkyl group and where the CN group is bonded to the B atom via the C atom, by reaction of an alkali metal salt of the formula (II) according to  claim 6  with [(C 6 H 5 ) 3 )P] 3 RhCl.    
   
   
       13 . Zr catalyst of the formula (V)  
       [Cp 2 ZrCH 3 ] [B(R F ) 4-x-y (CN) x F y ]  (V),  where    x=0, 1, 2, 3 or 4,    y=0, 1, 2 or 3,    x+y≦4    Cp=cyclopentadienyl    and in which    the ligands R F  may be identical or different and R F  stands for a perfluorinated or partially fluorinated C 1-12 -alkyl group and where the CN group is bonded to the B atom via the C atom, by reaction of an acid of the formula (I) according to  claim 1 , or the solvated form with Cp 2 Zr(CH 3 ) 2 .