Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D233/00—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings
  • C07D233/54—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members
  • C07D233/56—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, attached to ring carbon atoms
  • C07D233/58—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, attached to ring carbon atoms with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, attached to ring nitrogen atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D207/00—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom
  • C07D207/02—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
  • C07D207/04—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F5/00—Compounds containing elements of Groups 3 or 13 of the Periodic System
  • C07F5/02—Boron compounds
  • C07F5/022—Boron compounds without C-boron linkages
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F5/00—Compounds containing elements of Groups 3 or 13 of the Periodic System
  • C07F5/02—Boron compounds
  • C07F5/04—Esters of boric acids

Definitions

• the present invention relates to electrolyte formulations containing cyano- alkoxy-borate anions, their preparation and their use, in particular as part of electrolyte formulations for electrochemical or optoelectronic devices and special compounds containing cyano-alkoxy-borate anions.
• salts of formula I or formula as described below can on the one hand be used as part of electrolyte formulations for electrochemical or
• the salts can be used for the synthesis of ionic liquids of said formula I or I * .
• Ionic liquids or liquid salts are ionic species which consist of an organic cation and a generally inorganic anion. They do not contain any neutral molecules and usually have melting points below 373 K.
• EP 1205480 A1 describes tetrakisfluoroalkylborate salts and the use thereof as conductive salts or ionic liquids.
• WO 2006/010455 describes alkoxytris(perfluoroalkyl)borate salts and their use as precursor for the synthesis of ionic liquids or their use as ionic liquids.
• WO 20 0/086131 describes alkoxy-tricyano-borate salts as ionic liquids, especially potassium tricyanomethoxyborate, 1-ethyl-3-methylimidazolium tncyanomethoxyborate, N-(n-butyl)-2-methylpyridinium
• tricyanomethoxyborate tetraethylammonium tricyanomethoxyborate and tetra-(n-butyl)-phosphonium tricyanomethoxyborate.
• ionic liquids General applications of ionic liquids are described. The special application of said ionic liquids is not described.
• Electrolyte formulations form a crucial part of electrochemical and/or optoelectronic devices and the performance of the device largely depends on the physical and chemical properties of the various components of these electrolytes.
• electrolytes is used herein in the sense of electrolyte formulation as defined below and will be used equally to electrolyte formulation within the disclosure.
• electrochemical and/or optoelectronic devices and in particular of dye or quantum dot sensitized solar cells are reliability problems caused by the volatility of organic solvents based electrolytes. It is very difficult to maintain a tight sealing of the electrolyte in e.g. a DSC panel, which has to withstand the temperature differences of daily day-night cycles and the concomitant thermal expansion of the electrolyte.
• the abbreviation DSC means dye sensitized solar cell.
• This problem can be solved in principle by the use of ionic liquid-based electrolytes.
• Ionic liquid electrolytes for dye- sensitized solar cells see: William R Pitner et a/., "Application of Ionic Liquids in Electrolyte System” Green Chemistry, vol.6, (2010).
• Ionic liquids or liquid salts are typically ionic species which consist of an organic cation and a generally inorganic anion usually having melting points below 373 K.
• Various binary ionic liquid electrolytes have recently been applied to dye-sensitized solar cells. WO 2007/093961 and WO
• the object of the invention is therefore to provide electrolyte formulations for electrochemical and/or optoelectronic devices with improved power conversion efficiency in a broad temperature range (between -20 °C to 85 °C) such as a photovoltaic cell, a light emitting device, an electrochromic or photo-electrochromic device, an electrochemical sensor and/or biosensor, especially for dye or quantum dot sensitized solar cells, especially preferably for dye sensitized solar cells.
• the invention therefore relates to an electrolyte formulation comprising at least one compound containing borate anions of formula la
• x is 1 or 2 and R * denotes in each case, independently of one another, straight-chain or branched alkyl groups having 1 to 12 C atoms which can be partially subsituted by Hal and
• Hal denotes F, CI, Br or I.
• the invention relates in addition to electrolyte formulations comprising at least one compound of formula I
• z is 1 , 2, 3 or 4,
• x is 1 or 2 and R * denotes in each case, independently of one another, straight-chain or branched alkyl groups having 1 to 12 C atoms which can be partially subsituted by Hal and
• Hal denotes F, CI, Br or I.
• Hal denotes F or CI.
• Particularly preferably Hal denotes F.
• an electrolyte is any substance containing free ions that make the substance electrically conductive.
• the most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible.
• An electrolyte formulation according to the invention is therefore an electrically conductive medium, basically due to the presence of at least one substance that is present in a dissolved and or in molten state i.e. supporting an electric conductivity via motion of ionic species.
• the invention realtes in addition to compounds of formula
• R* denotes in each case, independently of one another, straight- chain or branched alkyl groups having 1 to 12 C atoms which can be partially subsituted by Hal and
• Hal denotes F, CI, Br or I, z is 1 , 2, 3 or 4,
• [Kt] z+ denotes H + ; an inorganic or organic cation selected from the group of NO + , H + , Li + , Na + , K + , Rb + , Cs + , or Mg 2 ⁇ Cu + , Cu 2+ , Zn 2+ , Ag ⁇ Ca 2+ , Y +3 , Yb +3 , La +3 , Sc +3 , Ce +3 , Nd +3 , Tb +3 , Sm +3 or complex (ligands containing) metal cations which include rare-earths, transitions or noble metals like rhodium, ruthenium, iridium, palladium, platinum, osmium, cobalt, nickel, iron, chromium, molybdenum, tungsten, vanadium, titanium, zirconium, hafnium, thorium, uranium, gold; or an oxonium cation of formula [(R°)
• R may be partially or fully substituted by halogens, in particular -F and/or -CI, or partially by -OH, -OR', -CN, -NR' 2 , -C(O)OH,
• R 2 in each case, independently of one another, denotes
• R 2 may be partially or fully substituted by halogens, in particular -F and/or -CI, or partially by -OH, -OR', -CN, -NR' 2) -C(O)OH, -C(O)NR' 2 , -SO 2 NR' 2 , -C(O)X, -SO 2 OH, -SO 2 X, -NO 2 , -SR ⁇ -S(O)R', -SO 2 R' and where one or two non-adjacent carbon atoms in R 2 which are not in the a-position may be replaced by atoms and/or atom groups selected from the group -O-, -S-, -S(O)-, -SO 2 -, -SO 2 O-, -C(O)-, -C(O)O-, -N + R' 2 -, -P(O)R'O-, -C(O)NR'-, -SO
• R 3 to R 7 each, independently of one another, denote
• R 3 to R 7 may be partially or fully sub- stituted by halogens, in particular -F and/or -CI, or partially by -OH, -OR', - NR' 2> -CN, -C(O)OH, -C(O)NR' 2 , -SO 2 NR' 2 , -C(O)X, -SO 2 OH, -SO 2 X, -SR', - S(O)R', -SO 2 R', -NO 2 and where one or two non-adjacent carbon atoms in R 3 to R 7 which are not in the a-position may be replaced by atoms and/or atom groups selected from the group -0-, -S-, -S(O)-, -S0 2 -, -S0 2 0-, -C(O)- , -C(O)0-, -N + R' 2 -, -P(0)RO
• R' each independently is H, non-fluorinated, partially fluorinated or perfluorinated straight-chain or branched C to Ci 8 -alkyl, saturated C 3 - to C 7 -cycloalkyl, non-substituted or substituted phenyl and X each independently is halogen; or a thiouronium cation, which conforms to the formula (6)
• R 3 to R 7 each, independently of one another, denote
• R' each independently is H, non-fluorinated, partially fluorinated or perfluorinated straight-chain or branched Cr to Ci 8 -alkyl, saturated C 3 - to C 7 -cycloalkyl, non-substituted or substituted phenyl and X each independently is halogen; or a guanidinium cation, which conforms to the formula (7)
• R 8 to R 13 each, independently of one another, denote
• R' each independently is H, non-fluorinated, partially fluohnated or perfluohnated straight-chain or branched Ci- to Cie-alkyl, saturated C 3 - to C 7 -cycloalkyl, non-substituted or substituted phenyl and X each independently is halogen; or [Kt] z+ conforms to the formula (8)
• HetN z+ denotes a heterocyclic cation selected from the group imidazolium 1 H-pyrazolium 3H-pyrazolium 4H-pyrazolium 1-pyrazol linium
• R 1 ' to R 4 ' each, independently of one another, denote
• R 1 ', R 3 ', R 4 ' are H and/or a straight- chain or branched alkyl having 1-20 C atoms;
• R r to R 4 may be partially or fully substituted by halogens, in particular -F and/or -CI, or partially by -OH, - OR', NR' 2) -CN, -C(O)OH, -C(O)NR' 2 , -SO 2 NR' 2 , -C(O)X, -SO 2 OH, -SO 2 X, - SR', -S(O)R ⁇ -SO 2 R', -NO 2 , but where R r and R 4' cannot simultaneously be fully substituted by halogens and where, in the substituents R 1 to R 4 , one or two non-adjacent carbon atoms which are not bonded to the heteroatom may be replaced by atoms and/or atom groups selected from the -O-, -S-, - S(O)-, -SO2-.
• Ci- to C 8 -alkyl saturated C3- to C 7 -cycloalkyl, non-substituted or substituted phenyl and X each independently is halogen.
• the compounds of formula I (and therefore also the compounds of formula I*) having organic cations are posessing low viscosity. Some of the viscosities are even lower compared with the corresponding
• 1-ethyl-3- methyl-imidazolium tetracyanoborate (emim TCB) has the dynamic viscosity of 22 mPas (at 20°C) and the corresponding 1-ethyl-3-methyl- imidazolium tricyano-methoxy-borate has a viscosity of 20 mPas (at 20°C).
• R * O an alkoxy group
• alkoxy groups (R * 0) are electron donating groups.
• the introduction of at least one alkoxy group to boron should increase the coordination ability of the tricyanoalkoxyborate anion, causing an increase in the viscosity of the organic salts having tricyanoalkoxyborate or dicyanodialkoxyborate anions. But the experimental results are opposite to this theoretical point of view.
• a straight-chain or branched alkyl group having 1 to 12 C atoms is, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert.-butyl, 1- (2,2-dimethyl)-propyl, pentyl, hexyl, heptyl, octyl, x-methylbutyl with x being 1 ; 2 or 3, x-methylpentyl with x being 1 ; 2; 3 or 4, x-methylhexyl with x being 1 ; 2; 3; 4 or 5, x-ethylpentyl with x being 1 , 2 or 3, x-ethylhexyl with x being 1 ; 2; 3 or 4, n-nonyl, n-decyl, n-undecyl or n-dodecyl, which can be partially substituted by Hal as defined above.
• Examples for preferred partially fluorinated alkyl groups are 2,2,2-trifluoroethyl, 3,3,3-trifluoropropyl, 4,4,4- trifluorobutyl or 1 ,1 ,1 ,3,3,3-hexafluoro-2-trifluoromethyl-propan-2-yl.
• R* in formula la or in formula I or in formula I * is in particular independently of each other straight-chain or branched alkyl with 1 to 8 C atoms which can be partially subsituted by Hal.
• R * in formula la or in formula I or in formula I* is particularly preferably independently methyl, ethyl, n-propyl, n- butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2,2,2-trifluoroethyl or 3,3,3- trifluoropropyl.
• [Kt] z+ can be an inorganic or organic cation.
• Compounds of formula I or of formula with alkali metal cations are preferred starting materials for the synthesis of compounds of formula I or compounds of formula I * having organic cations or metal cations other than the used alkali metal cation of the starting material for synthesis.
• the cations are preferably organic cations when the use of salts of formula is in the field of applications for ionic liquids or the organic salts per se.
• the cations are preferably metal cations when the use of the salts of formula I or formula I * is as precursors for the synthesis of ionic liquids, conducting salts with organic cations or Bronsted acids or in the field of catalysis, conductive salts for electrochemical devices or sensors and corresponding electrolyte formulations comprising said salts.
• the cations are preferably organic cations when the use of salts of formula I or formula is as part of the electrolyte formulations for optoelectronic devices, preferably for dye or quantum dot sensitized solar cells, especially preferably for dye sensitized solar cells.
• the organic cations are selected from the group comprising sulfonium, oxonium, ammonium, phosphonium, uronium, thiouronium, guanidinium cations or heterocyclic cations.
• Sulfonium cations can be described, for example by the formula (1) and oxonium cations can be described, for example, by the formula (2)
• R° independently of each other denotes straight-chain or branched alkyi groups having 1-8 C atoms, or nonsubstituted phenyl or phenyl which is substituted by R°, OR 0 , N(R°) 2 , CN or halogen and in case of sulfonium cations of formula (2) additionally denotes each independently (R"')2N and R'" is independently of each other straight-chain or branched Ci to C 6 alkyi.
• R° of the [(R°)3O] + cation or [(R°) 3 S] + cation is preferably independently of each other straight-chain alkyi having 1-8 C atoms, preferably having 1-4 C atoms, in particular methyl or ethyl, very particularly preferably ethyl.
• a particularly preferred sulfonium cation is diethyl-methylsulfonium.
• Ammonium cations can be described, for example, by the formula (3)
• Phosphonium cations can be described, for example, by the formula (4)
• R 2 in each case, independently of one another, denotes
• Uronium cations can be described, for example, by the formula (5)
• R 3 to R 7 each, independently of one another, denote
• R' each independently is H, non-fluorinated, partially fluorinated or perfluorinated straight-chain or branched C to Cis-alkyl, saturated C 3 - to C 7 -cycloalkyl, non-substituted or substituted phenyl and X each independently is halogen.
• R 8 to R 13 each, independently of one another, denote
• R' each independently is H, non-fluorinated, partially fluorinated or perfluorinated straight-chain or branched C to ds-alkyl, saturated C3- to C 7 -cycloalkyl, non-substituted or substituted phenyl and X each independently is halogen.
• Heterocyclic cations can be described, for example by the formula (8)
• HetN z+ denotes a heterocyclic cation selected from the group
• R 1 ' to R 4 ' each, independently of one another, denote
• R ', R 3 ', R 4 ' are H and/or a straight-chain or branched alkyl having 1-20 C atoms;
• one, two or three substltuents R 1 ' to R 4 ' may be partially or fully substituted by halogens, in particular -F and/or -CI, or partially by -OH, - OR', -NR' 2) -CN, -C(O)OH, -C(O)NR' 2 , -SO 2 NR' 2 , -C(O)X, -SO 2 OH, -SO 2 X, -SR', -S(O)R ⁇ -SO 2 R', -NO 2 , but where R 1' and R 4' cannot simultaneously be fully substituted by halogens and where, in the substltuents R 1 ' to R 4 ', one or two non-adjacent carbon atoms which are not bonded to the heteroatom may be replaced by atoms and/or atom groups selected from the group -O-, -S-, -S(O)-, -SO 2 -, -
• R' each independently is H, non-fluorinated, partially fluorinated or perfluorinated straight-chain or branched Ci- to Ci 8 -alkyl, saturated C 3 - to C 7 -cycloalkyl, non-substituted or substituted phenyl and X each independently is halogen.
• suitable substltuents R and R 2 to R 13 of the compounds of the formulae (3) to (7), besides H, are preferably: d- to C 20 -, in particular C-i- to C 14 -alkyl groups, and saturated or unsaturated, i.e. also aromatic, C 3 - to C 7 -cycloalkyl groups, which may be substituted by C-i- to C 6 -alkyl groups, in particular phenyl.
• the substituents R and R 2 in the compounds of the formula (3) or (4) may be identical or different.
• the substituents R and R 2 are preferably different.
• the substituents R and R 2 are particularly preferably methyl, ethyl, iso- propyl, propyl, butyl, sec-butyl, pentyl, hexyl, octyl, decyl or tetradecyl.
• [C(NR 8 R 9 )(NR 10 R 11 )(NR 12 R 13 )] + may also be bonded in pairs in such a way that mono-, bi- or polycyclic cations are formed.
• the carbocycles or heterocycles of the guanidinium cations indicated above may also be substituted by C to C6-alkyl, C-i - to C 6 -alkenyl, -CN, -N0 2 , F, CI, Br, I, -OH, -d-Ce-alkoxy, -NR' 2 , -SR ⁇ -S(O)R', -S0 2 R ⁇ -C(O)OH, -SO 2 NR 2, -SO2X' or -SO3H, where X and R' have a meaning indicated above, substituted or nonsubstituted phenyl or an nonsubstituted or substituted heterocycle.
• the carbocycles or heterocycles of the cations indicated above may also be substituted by d- to C 6 -alkyl, d- to C 6 -alkenyl, -CN, -NO 2 , F, CI, Br, I, -OH, -CrCe-alkoxy, -NR' 2l -SR', -S(O)R', -SO 2 R', -COOH, SO 2 NR' 2) SO 2 X or SO 3 H or substituted or nonsubstituted phenyl or an nonsubstituted or substituted heterocycle, where X and R' have a meaning indicated above.
• the substituents R 3 to R 13 are each, independently of one another, preferably a straight-chain or branched alkyl group having 1 to 16 C atoms.
• the substituents R 3 and R 4 , R 6 and R 7 , R 8 and R 9 , R 0 and R 11 and R 12 and R 13 in compounds of the formulae (5) to (7) may be identical or different.
• R 3 to R 13 are particularly preferably each, independently of one another, methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl, phenyl, hexyl or cyclohexyl, very particularly preferably methyl, ethyl, n-propyl, isopropyl, n-butyl or hexyl.
• suitable substituents R r to R 4 of compounds of the formula (8) are each, independently of one another, preferably,
• suitable substituents R 2 and R 3 of compounds of formula (8) are particularly preferably: H, C to C 20 -, in particular C to Ci 2 -alkyl groups, and saturated or unsaturated, i.e. also aromatic, C3- to C 7 -cycloalkyl groups, which may be substituted by d- to C 6 -alkyl groups, in particular phenyl.
• suitable substituents R and R 4 of compounds of formula (8) are particularly preferably, each independently of each other straight-chain or branched C to C 2 o-, in particular d- to C12- alkyl groups, and saturated or unsaturated, i.e. also aromatic, C 3 - to C 7 - cycloalkyl groups, which may be substituted by C to C6-alkyl groups, in particular phenyl.
• the substituents R 1 and R 4 are each, independently of one another, particularly preferably methyl, ethyl, allyl, iso-propyl, propyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, cyclohexyl, phenyl or benzyl. They are very particularly preferably methyl, ethyl, n-butyl or hexyl. In pyrrolidinium, piperidinium or indolinium compounds, the two substituents R and R 4 are preferably different.
• R 2 or R 3 is in each case, independently of one another, in particular H, methyl, ethyl, iso-propyl, propyl, butyl, sec-butyl, tert-butyl, cyclohexyl, phenyl or benzyl.
• R 2 is particularly preferably H, methyl, ethyl, iso-propyl, propyl, butyl or sec-butyl.
• R 2 and R 3 are very particularly preferably H.
• the C Ci2-alkyl group is, for example, methyl, ethyl, iso-propyl, propyl, butyl, sec-butyl or tert-butyl, furthermore also pentyl, 1-, 2- or 3-methylbutyl, 1 ,1-, 1 ,2- or 2,2-dimethylpropyl, 1-ethylpropyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl or dodecyl, which optionally may be fluorinated or
• perfluorinated means that all H atoms are substituted by F atoms in the given alkyl group.
• fluorinated means that at least one H atom of the given alkyl group is substituted by an F atom. Examples of “fluorinated” or “perfluorinated” groups are
• a straight-chain or branched alkenyl having 2 to 20 C atoms, in which a plurality of double bonds may also be present, is, for example, allyl, 2- or 3- butenyl, isobutenyl, sec-butenyl, furthermore 4-pentenyl, iso-pentenyl, hex- enyl, heptenyl, octenyl, -C 9 H 17 , -C 0 H 19 to -C20H39, preferably allyl, 2- or 3- butenyl, iso-butenyl, sec-butenyl, furthermore preferably 4-pentenyl, iso- pentenyl or hexenyl, which optionally may be partially fluorinated.
• fluorinated means that at least one H atom of the given alkyl group is substituted by an F atom.
• a straight-chain or branched alkynyl having 2 to 20 C atoms, in which a plurality of triple bonds may also be present, is, for example, ethynyl, 1- or 2- propynyl, 2- or 3-butynyl, furthermore 4-pentynyl, 3-pentynyl, hexynyl, hept- ynyl, octynyl, -C 9 H-15, -Ci 0 H 17 to -C20H37, preferably ethynyl, 1- or 2-propyn- yl, 2- or 3-butynyl, 4-pentynyl, 3-pentynyl or hexynyl, which optionally may be partially fluorinated.
• fluorinated means that at least one H atom of the given alkyl group is substituted by an F atom.
• a straight-chain or branched alkoxyalkyl having 2 to 12 C atoms is, for example, methoxy methyl, 1-methoxyethyl, 1-methoxypropyl, 1-methoxy-2- methyl-ethyl, 2-methoxy-propyl, 2-methoxy-2-methyl-propyl, 1- methoxybutyl, 1-methoxy-2,2-dimethyl-ethyl, 1-methoxy-pentyl, 1- methoxyhexyl, 1-methoxy-heptyl, ethoxymethyl, 1-ethoxyethyl, 1- ethoxypropyl, 1-ethoxy-2-methyl-ethyl, 1-ethoxybutyl, 1-ethoxy-2,2- dimethyl-ethyl, 1-ethoxypentyl, 1-ethoxyhexyl, 1-ethoxyheptyl,
• butoxymethyl 1-butoxyethyl, 1-butoxypropyl or 1-butoxybutyl. Particularly preferred is methoxymethyl, 1-methoxyethyl, 2-methoxy-propyl, 1- methoxypropyl, 2-methoxy-2-methyl-propyl or 1-methoxybutyl.
• Aryl-Ci-C 6 -alkyl denotes, for example, benzyl, phenylethyl, phenylpropyl, phenylbutyl, phenylpentyl or phenylhexyl, where both the phenyl ring and also the alkylene chain may be partially or fully substituted, as described above, by halogens, in particular -F and/or -CI, or partially by -OH, -OR', -NR'2, -CN, -C(O)OH, -C(0)NR' 2) -S0 2 NR' 2 , -C(O)X, -S0 2 OH, -S0 2 X, -SR', -S(O)R', -SO 2 R', -N0 2 .
• Non-substituted saturated or partially or fully unsaturated cycloalkyi groups having 3-7 C atoms are therefore cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopentenyl, cyclopenta-1,3-dienyl, cyclohexenyl, cyclohexa-1 ,3-dienyl, cyclohexa-1 ,4-dienyl, phenyl, cycloheptenyl, cyclo- hepta-1 ,3-dienyl, cyclohepta-1 ,4-dienyl or cyclohepta-1 ,5-dienyl, each of which may be substituted by d- to C 6 -alkyl groups, where the cycloalkyi group or the cycloalkyi group substituted by d- to C6-alkyl groups may in turn also be substituted
• substituted phenyl denotes phenyl which is substituted by C to C & - alkyl, C to C 6 -alkenyl, -CN, -N0 2 , F, CI, Br, I, -OH, -C C 6 -alkoxy, NR" 2 , - COOH, -SO2X', -SR", -S(O)R", -SO2R", SO 2 NR" 2 or SO 3 H, where X' denotes F, CI or Br and R" denotes a non-, partially or perfluorinated Ci- to C6-alkyl or C3- to C 7 -cycloalkyl as defined for R', for example 0-, m- or p- methylphenyl, 0-, m- or p-ethylphenyl, 0-, m- or p-propylphenyl, 0-, m- or p-isopropylphen
• heteroaryl is taken to mean a saturated or unsaturated mono- or bicyclic heterocyclic group having 5 to 13 ring members, in which 1 , 2 or 3 N and/or 1 or 2 S or O atoms may be present and the heterocyclic radical may be mono- or polysubstituted by C to C 6 -alkyl, C to C 6 -alkenyl, -CN, -NO2, F, CI, Br, I, -OH, -NR" 2 , -d-Ce-alkoxy, -COOH, -SO 2 X', -SO 2 NR" 2 , -SR", -S(O)R", -SO 2 R” or SO 3 H, where X' and R" have a meaning indicated above.
• the heterocyclic group is preferably substituted or nonsubstituted 2- or 3- furyl, 2- or 3-thienyl, 1-, 2- or 3-pyrrolyl, 1-, 2-, 4- or 5-imidazolyl, 3-, 4- or 5-pyrazolyl, 2-, 4- or 5-oxazolyl, 3-, 4- or 5-isoxazolyl, 2-, 4- or 5-thiazolyl, 3-, 4- or 5-isothiazolyl, 2-, 3- or 4-pyridyl, 2-, 4-, 5- or 6-pyrimidinyl, further- more preferably 1 ,2,3-triazol-l-, -4- or -5-yl, 1 ,2,4-triazol-1-, -4- or -5-yl, 1- or 5-tetrazolyl, 1 ,2,3-oxadiazol-4- or -5-yl, 1 ,2,4-oxadiazol-3- or -5-yl, 1 ,3,4- thiadiazol-2- or -5-yl, 1 ,2,
• 6- or 7-benzisoxazolyl 2-, 4-, 5-, 6- or 7-benzothiazolyl, 2-, 4-, 5-, 6- or 7- benzisothiazolyl, 4-, 5-, 6- or 7-benz-2,1 ,3-oxadiazolyl, 1-, 2-, 3-, 4-, 5-, 6-,
• Heteroaryl-CrC 6 -alkyl is, analogously to aryl-CrC 6 -alkyl, taken to mean, for example, pyridinylmethyl, pyridinylethyl, pyridinylpropyl, pyridinylbutyl, pyri- dinylpentyl, pyridinylhexyl, where the heterocycles described above may furthermore be linked to the alkylene chain in this way.
• HetN is preferably
• HetN 2+ is very particularly preferably
• Preferred 1 ,1-dialkylpyrrolidinium cations are, for example, 1 ,1-dimethyl- pyrrolidinium, 1 -methyl- 1-ethylpyrrolidinium, 1-methyl-1-propylpyrrolidinium, 1-methyl-1-butylpyrrolidinium, 1-methyl-1-pentylpyrrolidinium, 1-methyl-1- hexylpyrrolidinium, 1 -methyl-1 -heptylpyrrolidinium, 1 -methyl-1 -octylpyrroli- dinium, 1 -methyl-1 -nonylpyrrolidinium, 1 -methyl-1 -decylpyrrolidinium, 1 ,1- diethylpyrrolidinium, 1-ethyl-1-propylpyrrolidinium, 1 -ethyl-1 -butylpyrrolidin- ium,
• Preferred 1-alkyl-1-alkoxyalkylpyrrolidinium cations are, for example, 1-(2- methoxyethyl)-1 -methylpyrrolidinium, 1 -(2-methoxyethyl)-1 -ethyl- pyrrolidinium, 1-(2-methoxyethyl)-1-propylpyrrolidinium, 1-(2-methoxyethyl)- 1 -butylpyrrolidinium, 1 -(2-ethoxyethyl)-1 -methylpyrrolidinium,
• Preferred 1 ,3-dialkylimidazolium cations are, for example, 1-ethyl-3-methyl- imidazolium, 1-methyl-3-propylimidazolium, 1-methyl-2,3- dimethylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1-propyl-2,3- dimethylimidazolium, 1-butyl-2,3-dimethylimidazolium, 1 -butyl-3-methyl- imidazolium, 1-methyl-3-pentylimidazolium, 1-ethyl-3-propylimidazolium, 1 -butyl-3-ethylimidazolium, 1 -ethyl-3-pentylimidazolium, 1 -butyl-3-propyl- imidazolium, 1 ,3-dimethylimidazolium, 1 ,3-diethylimidazolium, 1 ,3- dipropy
• Preferred 1-alkoxyalkyl-3-alkylimidazolium cations are, for example 1-(2- methoxyethyl)-3-methylimidazolium, 1-(2-methoxyethyl)-3-ethylimidazolium, 1 -(2-methoxyethyl)-3-propylimidazolium, 1 -(2-methoxyethyl)-3-butyl- imidazolium, 1-(2-ethoxyethyl)-3-methylimidazolium, 1-ethoxymethyl-3- methylimidazolium.
• Preferred 1-alkenyl-3-alkylimidazolium cations are, for example 1-allyl-3- methyl-imidazolium or 1-allyl-2,3-dimethylimidazolium.
• Preferred 1-alkyl-pyridinium cations are for example, 1-methylpyridinium, 1-ethylpyridinium, 1-n-propylpyridinium, 1-isopropylpyridinium, 1-n- butylpyridinium, 1 -n-butyl-3-methylpyridinium, 1 -n-butyl-4-methylpyridinium, 1-n-butyl-3-ethylpyridinium, 1-n-pentylpyridinium, 1-n-hexylpyridinium, 1-n- heptylpyridinium, 1-n-octylpyridinium, 1-n-nonylpyridinium, 1-n- decylpyridinium, 1-n-undecyl-pyridinium or 1-n-dodecylpyridinium.
• the cation [Kt] z+ of the compound of formula I or formula I * may in addition also be inorganic, in particular a metal cation or NO + .
• the metal cation may comprise metals from groups 1 to 12 of the Periodic Table.
• Preferred metal cations are alkali metal cations, such as Li + , Na + , K + , Rb + , Cs + , Ag + , Mg 2+ , Cu ⁇ Cu 2+ , Zn 2+ ,Ca 2+ , Y +3 , Yb +3 , La +3 , Sc +3 , Ce +3 , Ce +4 , Nd +3 , Tb +3 , Sm +3 or complex (ligands containing) metal cations which include rare-earths, transitions or noble metals like Rhodium, Ruthenium, Iridium, Palladium, Platinum, Osmium, Cobalt, Nickel, Iron, Chromium, Molybdenium, Tungsten, Vanadium, Titanium, Zirconium, Hafnium,
• the alkali metal is preferably lithium, sodium or potassium.
• Electrolyte formulations comprising at least one compound of formula I in which [Kt] z+ is Li + can be preferably used in primary batteries, secondary batteries, capacitors, supercapacitors or electrochemical cells, optionally also in combination with further conductive salts and/or additives.
• organic cations of the compounds of formula I as part of the electrolyte formulation according to the invention are preferably sulfonium, ammonium, phosphonium cations of formula (1), (3) and (4) or heterocyclic cations of formula (8).
• organic cations of the compounds of formula according to the invention are preferably sulfonium, ammonium, phosphonium cations of formula (1), (3) and (4) or heterocyclic cations of formula (8).
• organic cations of the compounds of formula I as part of the electrolyte formulation according to the invention or of the compounds of formula are particularly preferably heterocyclic cations of formula (8) in which HetN z+ is imidazolium, pyrrolidinium or pyridinium, as defined above, where the substituents R 1 to R 4 each, independently of one another, have a meaning described above.
• the organic cation of the compound of formula I or formula is very particularly preferably imidazolium, where the substituents R 1 to R 4 each, independently of one another, have a meaning described above or has one of the particularly preferred meanings of 1 ,1- dialkylpyrrolidinium, 1-alkyl-l-alkoxyalkylalkylpyrrolidinium, 1 ,3- dialkylimidazolium, 1-alkenyl-3-alkylimidazolium or 1-alkoxyalkyl-3- alkylimidazolium as described above.
• Particularly suitable organic cations of compounds of the formula I or formula I* are 1-butyl-1-methylpyrrolidinium, 1-ethyl-3-methylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1-(2-methoxyethyl)-3-methylimidazolium, l-butyl-3-methylimidazolium, tributyl-methylammonium, tetra-n- butylammonium, tributyl-methylphosphonium, tetra-phenylphosphonium, diethyl-methylsulfonium, S-ethyl-N,N,N',N'-tetramethylisothiouronium, 1- allyl-3-methylimidazolium, 1-allyl-2,3-dimethylimidazolium, 1-cyanomethyl- 3-methylimidazolium, 1-methyl-3-propinylimidazolium, 1 ,1- dimethylpyrrolidinium
• Me + is an alkali metal cation, such as Li + , Na + , K + , Rb + , Cs + , preferably Na + and K + , and R * has a meaning as described above
• Me + is an alkali metal cation, such as Li + , Na + , K + , Rb + , Cs + , preferably Na + and K +
• R * has a meaning as described above
• the invention therefore also relates to a process for the preparation of compounds of the formula I in which [Kt] z+ is an alkali metal cation and x denotes 1 which denotes a compound of formula 1-1
• Me + is an alkali metal cation and R * has a meaning as described above comprising the reaction of a compound of formula II
• compounds of formula II can be synthesized by the reaction of an alkali metal alkoxylate (Me(OR * )) with a boric acid trialkylester B(OR * ) 3 , in which Me is the alkali metal and R * has a meaning as described herein.
• Me alkali metal alkoxylate
• B(OR * ) 3 boric acid trialkylester
• Trialkylsilylcyanide in which the alkyl groups independently denotes straight-chain or branched alkyl groups having 1 to 4 C atoms are in some cases commercially available or can be synthesised by known processes. For example, it is possible to generate trialkylsilylcyanide by the reaction of alkalimetalcyanide with trialkylsilylchloride in the presence of
• alkalimetaliodide and optionally elemental iodine M.T. Reetz, I.
• the alkalimetaliodide will be used in 0,1 mol/l related to 1 mol/l alkalicyanide and
• reaction has to be carried out in a dry atmosphere, for example under dry air, nitrogen or argon.
• the alkyl groups of trialkylsilylcyanide may be the same or different.
• trialkylsilylcyanides are such as trimethylsilylcyanide, triethylsilylcyanide, dimethylethylsilylcyanide, triisopropylsilylcyanide, tripropylsilylcyanide or tributylsilylcyanide.
• Useful organic solvents are for example, acetonitrile, dimethoxyethane, diglyme, tetrahydrofurane, or methyl-tert-butyl ether.
• trialkylsilylcyanide (three equivalents) or trialkylsilylcyanide in an excess are used.
• the preferred temperature range is room-temperature (25°C) to 80°C.
• the preferred solvent is acetonirile.
• the invention in addition, also relates to a process for the preparation of a compound of formula I as described before in which [Kt] z+ is an alkali metal cation and x denotes 2 or a compound of formula I * in which [Kt] z+ is an alkali metal cation which denotes a compound of formula I-2
• R* has a meaning as described before
• [Me] + denotes an alkali metal cation
• R * denotes in each case, independently of one another, straight-chain or branched alkyl groups having 1 to 12 C atoms with trialkylsilylcyanide at room temperature in the presence of an organic solvent and two equivalents of trialkylsilylcyanide per equivalent of the compound of formula II.
• the invention in addition, also relates to a process for the preparation of compounds of the formula I in which [Kt] z+ is an alkali metal cation and x denotes 1 which denotes a compound of formula 1-1
• Me + is an alkali metal cation and R * has a meaning as described above comprising the reaction of a compound of formula III
• [Me] + has a meaning as defined above with trialkylsilylcyanide and with alkoxytrialkylsilane in which alkoxy means OR * and R * has a meaning as described above and in which the alkyl groups of the silyl compounds independently denotes straight-chain or branched alkyl groups having 1 to 4 C atoms.
• this process preferably should be carried out in a dry atmosphere, for example under dry air, nitrogen or argon .
• the process for the synthesis of compounds of formula I in which [Kt] z+ is an alkali metal cation and x denotes 1 as described herein is carried out through reaction of an alkali metal tetrafluoroborate of formula Me[BF 4 ] with R * OH, MeCN and trialkylsilylchloride, in which Me is the alkali metal cation [Kt] z+ , R * has a meaning as described above and the alkyl group of the silicium compound is independently of each other straight-chain or branched alkyl with 1 to 4 C atoms.
• Me[BF 2 (CN) 2 ], in which Me is an alkali metal cation, can be used as starting material for the synthesis of compounds of formula I in which [Kt] z+ is an alkali metal cation and x denotes 1 as described herein by means of the reaction with trialkylsilyl cyanide and alkoxytrialkylsilanes.
• the invention therefore also relates to a process for the preparation of a compound of formula I or a compound of formula in which [Kt] z+ is another cation than the used alkali metal cation in the starting material in a salt-exchange reaction as described above, characterized in that an alkali metal salt of formula 1-1
• Kt has a meaning of an organic cation or a metal cation other than the alkali metal cation of the compound of formula 1-1 or formula I-2 and
• A denotes F ⁇ , CI ⁇ Br “ , I “ , OH “ (OH “ merely for the synthesis of compounds of formula l-1),[HF 2 ] “ , [CN] “ [SCN] “ , [ ⁇ 0(0)0] “ [ ⁇ 00(0)0] " [RiSO 3 ] - [R 2 C(O)O]- [R2SO3] - [R1OSO3] - [SiF 6 ] 2 - [BF 4 ] [HOCO2] - [HSO 4 ] 1 - [NO3] - [(Ri) 2 P(0)O] " , [R 1 (R 1 O)P(O)O] " , [(R 2 ) 2 P(O)O] " , [R 2 P(O)O 2 ] 2" , tosylate, malonate, the malonate optionally substituted with straight-chain or branched alkyl groups having 1 to 4 C atoms, [SO ] 2" or [
• R 2 is each independently of one another a straight-chain or branched perfluorinated alkyl group having 1 to 12 C atoms and where electroneutrality should be taken into consideration in the formula of the salt KtA.
• the invention therefore also relates to a process for the preparation of a compound of formula I in which [Kt] z+ is another cation than the used alkali metal cation in the starting material in a salt-exchange reaction as described above, characterized in that an alkali metal salt of formula I-2 [Me] + [B(CN) 2 (OR * ) 2 )r I-2
• Kt has a meaning of an organic cation or a metal cation other than the alkali metal cation of the compound of formula 1-1 or formula I-2 and
• A denotes F “ , CI “ Br “ , I “ [HF 2 ] ⁇ [CN] “ , [SCN] “ , [ ⁇ 0(0)0] "
• Ri is each independently of another H or a straight-chain or branched alkyl group having 1 to 12 C atoms and
• R 2 is each independently of one another a straight-chain or branched fluorinated or perfluorinated alkyl group having 1 to 12 C atoms or pentafluorophenyl and where electroneutrality should be taken into consideration in the formula of the salt KtA.
• R 2 is particularly preferred trifluoromethyl, pentafluoroethyl or nonafluorobutyl, very particularly preferred trifluoromethyl or pentafluoroethyl. is particularly preferred methyl, ethyl, n-butyl, n-hexyl or n-octyl, very particularly preferred methyl or ethyl.
• Substituted malonates are for example methyl malonate or ethyl malonate.
• the compounds of formula V are in most cases commercially available or can be synthesised by known processes. Known processes for the preparation of of compounds of formula V are described, for example, in P. Wasserscheid, T. Welton (Eds.), Ionic Liquids in Synthesis, Second Edition, WILEY-VCH, Weinheim, 2008.
• the anion in the formula V is preferably OH " (OH " merely for the synthesis of compounds of formula 1-1), CI “ , Br “ , ⁇ , [HF 2 ] ⁇ , [CN] “ , [SCN] ⁇ ,
• Suitable organic salts for the preparation of the compounds of the formula I or formula in which [Kt] 2+ is an organic cation are salts with cations of formula (1) to (8) or their preferred embodiments together with anions as defined as A described above or its preferred embodiments which means preferably salts of cations of formulae (1) to (8) or their preferred embodiments and OH “ (OH " merely for the synthesis of compounds of formula 1-1), CI " Br " , [CH 3 OS0 3 r. [CF 3 SO 3 ] " , [CH 3 SO 3 ] ⁇ or [(C 2 F 5 ) 2 P(0)or
• Suitable inorganic salts for the preparation of the compounds of the formula 1-1 in which [Kt] z+ is a metal cation e.g. from the group silver, magnesium, copper, zinc and calcium are, for example,
• reaction is advantageously carried out in water in the case of the compounds of formula 1-1 or in dry organic solvent in the case of the compounds of formula I-2, where temperatures of 10°-100°C, preferably 15°-60°C, particularly preferably room temperature, are suitable.
• reaction can alternatively also be carried out for the compounds of formula 1-1 in organic solvents at temperatures between 10° and 100°C.
• Suitable solvents are acetonitrile, dioxane,
• dichloromethane dimethoxyethane or an alcohol, for example methanol or ethanol.
• this salt-exchange reaction it is possible to use the compounds of formulae 1-1 or I-2 directly after their synthesis as crude materials without purified isolation. It is preferred to separate volatile side products such as the reaction products trialkylsilylfluoride and
• the present invention furthermore relates to the use of the compounds of formula I* with organic cations as described in detail above as solvent or solvent additive, as acidic catalyst (in the case [Kt] z+ is H + ) as phase-transfer catalyst, as extractant, as heat-transfer medium, as surface-active substance, as plasticiser, as conductive salt, organic salt or additive in electrochemical cells.
• compounds of formula I can be used as acidic catalysts if ]Kt] z+ is H + .
• organic salts of formula I* are suitable in any type of reaction known to the person skilled in the art, for example for transition-metal- or enzyme-catalysed reactions, such as, for example, hydroformylation reactions, oligomerisation reactions, esterifications or isomerisations, where the said list is not exhaustive.
• the organic salts of formula I * can be employed to separate off reaction products, but also to separate off impurities, depending on the solubility of the respective component in the ionic liquid.
• the ionic liquids may also serve as separation media in the separation of a plurality of components, for example in the distillative separation of a plurality of components of a mixture.
• organic salts of formula are solvents for carbohydrate containing solids in particular biopolymers and derivatives or degredation products thereof.
• these new compounds can be applied as lubricants, working fluids for maschines, such as compressors, pumps or hydraulic devices.
• a further field of application is the field of particle or nanomaterial synthesis where these ionic liquids can act as medium or additive.
• the compounds of formula I * with organic cations, e.g. ionic liquids according to this invention may be preferably used in electrochemical and/or optoelectronic devices, especially in electrolyte formulations.
• Electrolyte formulations comprising compounds of formula I or at least one compound of formula I * in which [Kt] 2+ is Li + or an organic cation can be preferably used in primary batteries, secondary batteries, capacitors, supercapacitors or electrochemical cells, optionally also in combination with further conductive salts and/or additives, as constituent of a polymer electrolyte or phase-transfer medium.
• Preferred batteries are lithium batteries or lithiumion batteries.
• a preferred capacitor is a lithiumion capacitor.
• Electrolyte formulations comprising at least one compound of formula I as described or preferably described above can be preferably used in electrochemical and/or optoelectronic devices such as a photovoltaic cell, a light emitting device, an electrochromic or photo-electrochromic device, an electrochemical sensor and/or biosensor, particularly preferred in a dye sensitised solar cell.
• electrochemical and/or optoelectronic devices such as a photovoltaic cell, a light emitting device, an electrochromic or photo-electrochromic device, an electrochemical sensor and/or biosensor, particularly preferred in a dye sensitised solar cell.
• Electrolyte formulations according to the invention are alternatives to already known electrolyte formulations. They show especially in the field of electrolyte formulations of dye sensitised solar cells an increased power conversion efficiency particularly under low temperature.
• the advantage of the use of compounds of formula I as described above is their low viscosity, and subsequently the smaller Nernst diffusion resistance of the oxidant spiecies especially, at lower temperature.
• formulations range from 0.1 to 5.5 M, preferably from 0.8 to 3.5 M. This molar concentration in the electrolyte may be achieved with one or more compounds of formula I or one or more compounds of formula in which [Kt] z+ is an inorganic or an organic cation.
• the molar concentration is achieved with at least one compound of formula I or of formula I * in which [Kt] z+ is an organic cation as described or preferably described above.
• the molar concentration refer to the concentration at 25°C.
• the present invention relates furthermore to an electrolyte formulation comprising at least one compound of formula I or of formula I * as described above or preferably described together with redox active species such as iodide/tri-iodide, Ferrocene derivatives or Co(ll)/Co(lll) complex couples such as Co(ll)/Co(lll)(dbbip) 2 in which dbbip means 2,6-bis(1'- butylbenzimidazol-2'-yl)pyridine, Co(ll)/Co(lll)(bpy)3 where bpy denotes bipyridine or alkylated bipyridine derivates thereof, the counter anion being either perchlorate, fluoroperfluoroalkylphosphate such as
• perfluoroethylpentafluorophosphate or (fluoro)cyanoborate, particularly tetracyanoborate, preferably a redox couple of iodine and at least one iodide salt.
• the electrolyte formulation of the invention preferably comprises iodine (l 2 ). Preferably, it comprises from 0.0005 to 7 mol/dm 3 , more preferably 0.01 to 5 mol/dm 3 and most preferably from 0.05 to 1 mol/dm 3 of l 2 .
• the iodide salt consists of an inorganic or organic cation and as anion.
• organic cations preferably be used as already described for the compounds of formula I or formula .
• the electrolyte formulation comprises at least one iodide salt in which the organic cation is
• R 2 and R 3 each, independently of one another, denote H or straight-chain or branched alkyl having 1 to 20 C atoms,
• R 1 and R 4 each, independently of one another, denote
• the at least one iodide salt are 1-ethyl-3- methylimidazolium iodide (emim I), 1-propyl-3-methylimidazolium iodide (pmim I), 1-butyl-3-methyl-imidazolium iodide (bmim I), 1-hexyl-3- methylimidazolium iodide (hmim I), 1 ,3-dimethyl-imidazolium iodide (mmim I), 1-allyl-3-methylimidazolium iodide (amim I), N-butyl-N-methyl- pyrrolidinium iodide (bmpl I) or ⁇ , ⁇ -dimethyl-pyrrolidinium iodide (mmpl I).
• emim I 1-ethyl-3- methylimidazolium iodide
• pmim I 1-propyl-3-methylimidazolium iodide
• the electrolyte formulation is a binary system, it comprises two salts, one further salt or iodide salt and a compound of formula I or formula I * as described above. If the electrolyte formulation is a ternary system, it comprises two further salts and/or iodide salts and a compound of formula I or formula as described above.
• the binary system comprises 90-10 weight %, preferably 70-30 weight %, more preferably 55-40 weight % of the further salt or iodide salt and 10-90 weight %, preferably 30-70 weight % or more preferably 45-60 weight % of the compound of formula I as described above.
• the electrolyte formulation comprises at least one further salt with organic cations comprising a quaternary nitrogen and an anion selected from a halide ion, such as F “ , CI " , a polyhalide ion, a fluoroalkanesulfonate, a
• fluoroalkanecarboxylate a tris(fluoroalkylsulfonyl)methide, a
• hexafluorophosphate a tris- , bis- and mono-(fluoroalkyl)fIuorophosphate, a tetrafluoroborate, a dicyanamide, a tricyanomethide, a tetracyanoborate, a thiocyanate, an alkylsulfonate or an alkylsulfate, with fluoroalkane-chain having 1 to 20 C atoms, preferably perfluorinated, fluoroalkyi having 1 to 20 C atoms and alkyl having 1 to 20 C atoms. Fluoroalkane-chain or fluoroalkyi is preferably perfluorinated.
• the further salts are selected from salts comprising anions such as thiocyanate or tetracyanoborate, particularly preferred further salts are tetracyanoborates.
• the cation of the at least one further salt or of a preferred further salt may be selected amongst organic cations as defined above for the compounds of formula I or formula I * including also the preferred meanings.
• guanidinium thiocyanate may be added to the electrolyte formulation according to the invention.
• the electrolyte formulation of the present invention further comprises at least one compound containing a nitrogen atom having non-shared electron pairs.
• compounds having non-shared electron pairs include imidazole and its derivatives, particularly benzimidazole and its derivatives.
• the electrolyte formulation of the present invention comprises less than 50 % of an organic solvent.
• the electrolyte formulation comprises less than 40%, more preferably less than 30%, still more preferably less than 20% and even less than 10 %.
• the electrolyte formulation comprises less than 5% of an organic solvent. For example, it is substantially free of an organic solvent. Percentages are indicated on the basis of weight %.
• Organic solvents if present in such amounts as indicated above, may be selected from those disclosed in the literature.
• the solvent if present, has a boiling point higher than 160 degrees centigrade, more preferably higher than 190 degrees such as propylene carbonate, ethylene carbonate, butylene carbonate, gamma-butyrolactone, gamma- valerolactone, glutaronitrile, adiponitrile, N-methyloxazolidinone, N- methylpyrrolidinone, ⁇ , ⁇ '-dimethylimidazolidinone, N,N-dimethylacetamide, cyclic ureas preferably 1 ,3-dimethyl-2-imidazolidinone or 1 ,3-dimethyl- 3,4,5,6-tetrahydro-2(1H)-pyrimidinone, glymes preferably tetraglyme, sulfolane, sulfones which are preferably asymmetrically substituted such as 2-ethane
• a solvent is present in the electrolyte formulation, there may further be comprised a polymer as gelling agent, wherein the polymer is
• polyvinylidenefluoride polyvinylidene-hexafluropropylene, polyvinylidene- hexafluoropropylene-chlorotrifluoroethylene copolymers, nafion,
• polyethylene oxide polymethylmethacrylate, polyacrylonitrile,
• polypropylene polystyrene, polybutadiene, polyethyleneglycol,
• polyvinylpyrrolidone polyaniline, polypyrrole, polythiophene.
• the purpose of adding these polymers to electrolyte formulations is to make liquid electrolytes into quasi-solid or solid electrolytes, thus improving solvent retention, especially during aging.
• the electrolyte formulation of the invention may further comprise metal oxide nanoparticles like SiO 2> TiO 2) AI 2 O 3 , MgO or ZnO, for example, which are also capable of increasing solidity and thus solvent retention.
• the electrolyte formulation of the invention has many applications. For example, it may be used in an optoelectronic and/or electrochemical device such as a photovoltaic cell, a light emitting device, an electrochromic or photo-electrochromic device, an electrochemical sensor and/or biosensor. Also the use in electrochemical batteries is possible, for example in a lithium ion battery or a double layer capacitor.
• an optoelectronic and/or electrochemical device such as a photovoltaic cell, a light emitting device, an electrochromic or photo-electrochromic device, an electrochemical sensor and/or biosensor.
• electrochemical batteries for example in a lithium ion battery or a double layer capacitor.
• the present invention therefore relates further to the use of the electrolyte formulation as described in detail above in an electrochemical and/or optoelectronic device which is a photovoltaic cell, a light emitting device, an electrochromic or photo-electrochromic device, an electrochemical sensor and/or biosensor.
• the electrolyte formulation may be used in dye sensitized solar cells.
• the present invention therefore relates furthermore to an electrochemical and/or optoelectronic device, for example a photovoltaic cell, a light emitting device, an electrochromic or photo-electrochromic device, an
• electrochemical sensor biosensor, primary battery, secondary battery, capacitor or supercapacitor comprising an electrolyte formulation
• z is 1, 2, 3 or 4,
• x is 1 or 2 and R * in each case, independently of one another, straight- chain or branched alkyl groups having 1 to 12 C atoms which can be partially subsituted by Hal and
• Hal denotes F, CI, Br or I or a preferred embodiment of such a compound of formula I as described above.
• the device of the resent invention is a dye or quantum dot sensitized solar cell, particularly preferably a dye sensitized solar cell.
• Quantum dot sensitized solar cells are disclosed in US 6,861 ,722, for example.
• a dye is used to absorb the sunlight to convert into the electrical energy.
• Examples of dyes are disclosed in EP 0 986 079 A2, EP 1 180 774 A2 or EP 1 507 307 A1.
• Preferred dyes are organic dyes such as MK-1 , MK-2 or MK-3 (its structures are described in figure 1 of N. Koumura et al, J.Am.Chem.Soc. Vol 128, no.44, 2006, 14256-14257), D102 (CAS no. 652145-28-3), D-149 (CAS no. 786643-20-7), D205 (CAS no. 936336-21-9), YD-2 as described in T. Bessho et al, Angew. Chem. Int. Ed. Vol 49, 37, 6646-6649, 2010, Y123 (CAS no. 1312465-92-1), bipyridin-Ruthenium dyes such as N3 (CAS no. 141460-19-7), N719 (CAS no.
• Particularly preferred dyes are Z907 or Z907Na which are both an amphiphilic ruthenium sensitizer or D205.
• Very particularly preferred dyes are Z907 or Z907Na.
• the dye is coadsorbed with a phosphinic acid.
• a phosphinic acid is bis(3,3-dimethyl-butyl)-phosphinic acid (DINHOP) as disclosed in M. Wang et al, Dalton Trans., 2009, 10015- 10020.
• the dye Z907Na means NaRu(2,2'-bipyridine-4-carboxylic acid-4'- carboxylate)(4,4'-dinonyl-2,2'-bipyridine)(NCS) 2 .
• a dye-sensitized solar cell comprises a photoelectrode, a counter electrode and, between the photoelectrode and the
• the device comprises a semiconductor, the electrolyte formulation as described above and a counter electrode.
• the semiconductor is based on material selected from the group of Si, Ti0 2 , Sn0 2 , Fe 2 O 3 , W0 3 , ZnO, Nb 2 0 5 , CdS, ZnS, PbS, Bi 2 S 3 , CdSe, GaP, InP, GaAs, CdTe, CulnS 2 , and/or CulnSe 2 .
• the semiconductor comprises a mesoporous surface, thus increasing the surface optionally covered by a dye and being in contact with the electrolyte.
• the semiconductor is present on a glass support or plastic or metal foil.
• the support is conductive.
• the device of the present invention preferably comprises a counter electrode.
• a counter electrode for example, fluorine doped tin oxide or tin doped indium oxide on glass (FTO- or ITO-glass, respectively) coated with Pt, carbon of preferably conductive allotropes, polyaniline or poly (3,4- ehtylenedioxythiophene) (PEDOT).
• Metal substrates such as stainless steel or titanium sheet may be possible substrates beside glass.
• the device of the present invention may be manufactured as the
• the sensitized semiconducting material serves as a photoanode.
• the counter electrode is a cathode.
• the present invention provides a method for preparing a photoelectric cell comprising the step of bringing the electrolyte formulation of the invention in contact with a surface of a semiconductor, said surface optionally being coated with a sensitizer.
• the semiconductor is selected from the materials given above, and the sensitizer is preferably selected from quantum dots and/or a dye as disclosed above, particularly preferably selected from a dye.
• the electrolyte formulation may simply be pured on the semiconductor.
• it is applied to the otherwise completed device already comprising a counter electrode by creating a vacuum in the internal lumen of the cell through a hole in the counter electrode and adding the electrolyte formulation as disclosed in the reference of Wang et al., J. Phys. Chem. B 2003, 107, 14336.
• the synthesized compounds are characterized through Raman spectroscopy, NMR spectroscopy or elemental analysis.
• the NMR spectrum is measured in acetone-D6 (Bruker Avance III with deuterium as lock). Used frequencies:: 1 H: 400,17 MHz, 19 F: 376,54 MHz, 11 B: 128,39 MHz , 31 P: 161 ,99 MHz and 3 C: 100,61 MHz, external references: TMS for 1 H and 13 C ; CCI 3 F - for 9 F and BF 3 Et 2 0 - for 11 B.
• the filtrate is evaporated to a volume of 5 ml in a rotary evaporator at 40°C, and chloroform (100 ml) is added.
• the precipitate formed (Li[B(CN) 3 OCH 3 ]) is filtered off and dried in vacuo. Yield: 883 mg (6.964 mmol, 99.5%).
• the product is characterized by means of NMR and Raman spectroscopy. The spectra are identical to the spectra described in Example 1A.
• the product is extracted from the aqueous phase with tetrahydrofuran (3 * 50 ml).
• the combined THF phases are dried using Na 2 C0 3) filtered and evaporated to dryness in vacuo.
• the beige residue obtained is washed onto a frit (D4) using CH 2 CI 2 (50 ml) and dried in vacuo. Yield: 1.8 g (12.6 mmol, 68%).
• the product is characterized by means of NMR, Raman spectroscopy and mass spectrometry (MS):
• a structural analysis of a mono-crystal of the above described salt confirms that one molecule water is present per unit of the sodium salt.
• the product is extracted from the aqueous phase with tetrahydrofuran (5 * 100 ml).
• the combined THF phases are dried using Na 2 C03, filtered and evaporated to dryness in vacuo.
• the beige residue obtained is washed with CH 2 CI 2 (3 * 50 ml) until colourless and is dried in vacuo. Yield: 34.3 g (240.0 mmol, 91%).
• the product is characterized by means of NMR and Raman spectroscopy. The spectra are identical to the spectra described in Example 2A.
• the product comprises Na[BF ] (4%) and Na[BF 2 (CN) 2 ] (9%).
• Na[BH 4 ] (10.0 g, 264.5 mmol) is taken up in ethanol (600 ml). The reaction mixture is heated under reflux for 12 hours. Excess ethanol is removed at 70°C in a rotary evaporator. The residue is dried in vacuo and taken up in a suspension of NaCN (80.0 g, 1632.3 mmol), Nal (10.0 g, 66.7 mmol) and (CH 3 ) 3 SiCI (200.0 ml, 1583.2 mmol) in acetonitrile (25 ml) which has previously been stirred for two days. The resultant suspension is stirred at 25°C for 6 days and freed from all volatile constituents in vacuo.
• Na[B(OCH 2 CF 3 ) 4 ] (1.0 g, 2.4 mmol) is taken up in (CH 3 ) 3 SiCN (15.0 ml, 112.5 mmol), and the mixture is stirred at 80°C for 2 days. The volatile constituents are subsequently removed, and the black residue is dissolved in H 2 0 2 (30%, 20 ml). Na 2 C0 3 is added to the solution. The peroxide fraction is reduced using Na 2 S 2 0 5 , and the solution is extracted with tetrahydrofuran (3 ⁇ 20 ml). The THF phases are dried using Na 2 CO 3t filtered and evaporated to dryness in vacuo.
• K[BH 4 ] (10.0 g, 185.5 mmol) is taken up in methanol (500 ml, 12.3 mol) in a flask with magnetic stirrer bar (flask 1) with evolution of gas (H 2 ), and the mixture is heated under reflux for two hours.
• the reaction mixture is evaporated to dryness in a rotary evaporator, and the colourless residue is dried overnight in vacuo.
• the CH 2 CI 2 phase is subsequently washed with distilled water (3 x 5 ml), dried using MgSO 4 , filtered and evaporated in a rotary evaporator.
• the ionic liquid obtained is subsequently dried at 60°C in vacuo. Yield of tetraethylammonium [B(CN) 3 OCH 3 ], which is solid at room temperature: 10.0 g (39.9 mmol, 84%). Melting point: 33°C.
• the product is characterized by means of NMR and Raman spectroscopy:
• Tetrabutylammonium hydroxide, [TBA]OH (-40% in water, -1.5 M, 25.0 ml, 37.5 mmol), is added to a solution of Na[B(CN) 3 OCH 3 ] (5.2 g, 36.4 mmol) in distilled water (10 ml).
• CH 2 CI 2 (50 ml) is added to the emulsion obtained, and the mixture is stirred for 10 minutes.
• the CH2CI 2 phase is then separated off, washed with distilled water (3 x 5 ml), dried using MgSO 4 and filtered.
• the solution is evaporated in vacuo, and the ionic liquid obtained is dried in vacuo.
• Example 11 Preparation of 1-ethyl-3-methylimidazolium [B(CN) 3 OC 2 H 5 ] C 2 H5-N0N-CH 3 + Na[B(CN) 3 OC 2 H 5 ] - ⁇ C 2 H 5 -N( ⁇ )N-CH 3 + NaCI
• Trimethylsilylcyanide, TMSCN (1.0 mL, 7.499 mmol) is added to a suspension of Na[B(OMe) 4 ] (592 mg, 3.749 mmol) in dry acetonitrile (30 mL) and stirred for further 12 hours at room temperature in dry atmosphere. The stirring is stopped and the solid material is allowed to settle. The clear liquid phase is transferred into a second flask and all volatiles are removed under reduced pressure. The yield of the white solid Na[B(OMe) 2 (CN) 2 ] is 440 mg (3.08 mmol, 82 % related to Na[B(OMe) ].)
• Example A Formulations and device
• electrolyte formulations are synthesized to demonstrate the advantage of electrolyte formulations according to the invention relative to electrolyte formulations of the prior art containing EMIM TCB.
• the following electrolyte mixtures are prepared containing in addition 10 molar amounts of NBB, 5 molar amounts of Iodine and 2 molar amounts of guanidinium thiocyanate.
• Electrolyte 2 given in the molar ratio: 36 mmim I, 36 emim I, 72 emim TCB
• Electrolyte 3 given in the molar ratio:
• Electrolyte 6 given in the molar ratio:
• Electrolyte 7 given in the molar ratio:
• Electrolyte 8 given in the molar ratio:
• Electrolyte 9 given in the molar ratio:
• Electrolyte 13 given in the molar ratio:
• emim I 1-ethyl-3-methylimidazolium iodide
• sm3 I trimethylsulfonium iodide.
• the dye sensitized solar cells are fabricated as disclosed in US 5,728,487 or WO 2007/093961:
• a double-layer, mesoporous TiO 2 electrode was prepared as disclosed in Wang P et al., J. Phys. Chem. B 2003, 107, 14336, in particular page 14337, in order to obtain a photoanode consisting of a double layer structure.
• a transparent nanoporous T1O2 electrode a screen printing paste containing terpineol solvent and nanoparticulate T1O2 of anatase phase with 20 nm diameter was deposited on a transparent conductive substrate to 5 mm x 5 mm squared shape by using a hand printer. The paste was dried for 10 minutes at 120 degrees Celsius.
• Another screen printing paste containing T1O2 with 400 nm diameter was then deposited on top of the nanoporous layer to prepare an opaque layer.
• the double layer film was then sintered at 500 degrees Celsius for an hour with the result of an underlying transparent layer (7 microns thick) and a top opaque layer (4 microns thick).
• the electrode was immersed in 40 mM aqueous solution of TiCI 4 (Merck) for 30 minutes at 70 degrees Celsius and then rinsed with pure water sufficiently.
• TiCI 4 -treated electrode was dried at 500 degrees Celsius for 30 minutes just before dye sensitization.
• the counter electrode was prepared with thermal pyrolysis method as disclosed in the reference above.
• a droplet of 5 mM solution of platinic acid (Merck) was casted at 8 ⁇ / ⁇ 2 and dried on a conductive substrate.
• the dye sensitized solar cell was assembled by using 30 micron thick Bynel (DuPont, USA) hot-melt film to seal up by heating. The internal space was filled with each of the electrolyte
• the dye Z907 is an amphiphilic ruthenium sensitizer Ru(2,2'-bipyridine 4,4'- dicarboxylic acid) (4,4'-dinonyl-2,2'-bipyridine)(NCS)2 or synonymously
• Air Mass 1.5 Global (AM 1.5G) simulated sunlight is calibrated spectrally according to Seigo Ito et al, "Calibration of solar simulator for evaluation of dye-sensitized solar cells", Solar Energy Materials & Solar Cells, 82, 2004, 421.
• Energy conversion efficiency is generally the ratio between the useful output of an energy conversion machine and the input of light radiation, in energy terms, determined by using adjustable resistant load to optimize the electric power output.
• Table 2 shows detailed photovoltaic parameters of the devices made according to example A represented by the short-circuit photocurrent density (Jsc), the open-circuit photovoltage (V oc ), the fill factor (FF) and the power conversion efficiency ( ⁇ )

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