Iron tetraphenylborate

Cft8Hft8Fi2N6P Pd3f Hexakis(methylisocyano)bis(triphenylphosphine)tri-palladium(II) di(hexafluorophosphate), 42B, 987 Ca 8H5 8ASaBFeN202S, NitrosyIbis(0-phenylenebis(dimethylarsine))(thio-cyanato-N)iron tetraphenylborate acetone, 43B, 1433 Ca 8Hs 6CI3F6P7RU2, Tri-M chloro-hexakis(dimethylphenylphosphine)di-ruthenium(II) hexafluorophosphate, 42B, 988 Ca8Hs8P2Pt2Si2f trans-Di-M hydrido-bis(tricyclohexylphosphine(tri-ethylsilyDplatinum), 44B, 1082... 

Ce cHg 2BFeN20P3, Nitrosyl(tris(2-diphenyIphosphinoethyl)amine)iron tetraphenylborate, 42B, 999... 

It is noteworthy that carbene function may be manifested in the derivatives of tris(imidazol-l-yl)borate 44 (96AGE310). Its reaction first with n-butyllithium, then with iron(II) chloride, and finally with sodium tetraphenylborate gives the iron(III) carbene derivative 45. 

Discussion. Potassium may be precipitated with excess of sodium tetraphenyl-borate solution as potassium tetraphenylborate. The excess of reagent is determined by titration with mercury(II) nitrate solution. The indicator consists of a mixture of iron(III) nitrate and dilute sodium thiocyanate solution. The end-point is revealed by the decolorisation of the iron(III)-thiocyanate complex due to the formation of the colourless mercury(II) thiocyanate. The reaction between mercury( II) nitrate and sodium tetraphenylborate under the experimental conditions used is not quite stoichiometric hence it is necessary to determine the volume in mL of Hg(N03)2 solution equivalent to 1 mL of a NaB(C6H5)4 solution. Halides must be absent. 

Standardisation. Pipette 10.0 mL of the sodium tetraphenylborate solution into a 250 mL beaker and add 90 mL water, 2.5 mL 0.1 M nitric acid, 1.0 mL iron(III) nitrate solution, and 10.0 mL sodium thiocyanate solution. Without delay stir the solution mechanically, then slowly add from a burette 10 drops of mercury(II) nitrate solution. Continue the titration by adding the mercury(II) nitrate solution at a rate of 1-2 drops per second until the colour of the indicator is temporarily discharged. Continue the titration more slowly, but maintain the rapid state of stirring. The end point is arbitrarily defined as the point when the indicator colour is discharged and fails to reappear for 1 minute. Perform at least three titrations, and calculate the mean volume of mercury(II) nitrate solution equivalent to 10.0 mL of the sodium tetraphenylborate solution. 

Pipette 25.0 mL of the potassium ion solution (about 10 mg K + ) into a 50 mL graduated flask, add 0.5 mL 1M nitric acid and mix. Introduce 20.0 mL of the sodium tetraphenylborate solution, dilute to the mark, mix, then pour the mixture into a 150mL flask provided with a ground stopper. Shake the stoppered flask for 5 minutes on a mechanical shaker to coagulate the precipitate, then filter most of the solution through a dry Whatman No. 40 filter paper into a dry beaker. Transfer 25.0 mL of the filtrate into a 250 mL conical flask and add 75 mL of water, 1.0 mL of iron(III) nitrate solution, and 1.0 mL of sodium thiocyanate solution. Titrate with the mercury(II) nitrate solution as described above. 

In the previous study [46], various kinds of cations and anions (listed in Table 2) were extracted from water to NB using several extractants tetraphenylborate (TPB ) and dipicrylaminate (DPA ) for the cations -Bu4N+, -Pen4N+, -Hep4N+, and tris(l,10-phenanthroline)iron(II) ([Fe(phen)3] +) for the anions. The increase in the water concentration in the NB phase, A[H20], with extraction of an ion was evaluated as a function of equilibrium concentration of the ion in NB. A typical example, obtained in the DPA ... 

Bedford and coworkers disclosed iron-catalyzed Suzuki-Miyaura-type coupling reactions of benzyl bromides with sodium tetraphenylborate in the presence of 5 mol% 15 as the catalyst and 10 mol% of dianisylzinc as a promoter. No reaction occurred in its absence. The coupling furnished 38-88% yield of 3 (entry 26) [66]. The transformation proceeds probably by initial B-Zn transmetalation. The resulting arylzinc transfers the aryl group to the iron catalyst as in the Negishi couplings above. An aryliron(I) complex was proposed to be formed initially. 

BN RhC44HM, Rhodium , tetrakis(l-isocy-anobutane)-, tetraphenylborate(l -), 21 50 BN C Hio, Borate(l -), hydrotris(pyrazolato)-, copper complex, 21 108 BN6Ci5H22, Borate(l -), tris(3,5-dimethylpyr-azolato)hydro-, copper complex, 21 109 BN8Ci2Hi2, Borate(l-), tetrakis(pyrazolato)-, copper complex, 21 110 BjFeN CjoH,, Iron(II), [tris[p.-[(l,2-cy-clohexanedione dioximato)-0 0 ]diphenyl-diborato(2 — )]-NJI JI" X " JI"",... 

B2N4P4Rh2C aH,20, Rhodium(l), tetrakis-(1 -isocyanobutane)bis[methylenebis-(diphenylphosphine)ldi-, bis[tetraphenylborate(l -)], 21 49 BjNACsoHm, Borate(2-), tris[p.-[(l,2-cy-clohexanedione dioximato)-0 O ]diphenyldi-, iron complex, 21 112 B20,Ci4H2g, Boron, bis-p-(2,2-dimethylpropa-noato-0,0 ),-diethyl-p.-oxo-di-, 22 196 B2S3C2H6, [l0B2]-l,2,4,3,5-Trithiadiborolane, 3,5-dimethyl-, 22 225... 

B2Fe20gCgHg, Iron, hexacarbonyl[p-[hexa-hydrodiborato(2—)]]di-. 29 269 B2Hg, Diborane(6), 27 215 B2NgRuC5gHgg, Ruthenium(II), (t) -1,5-cyclooctadiene)tetrakis(hydrazine)-, bis-[tetraphenylborate(l-)], 26 73 B2NgRuCg( H7g, Ruthenium(II), (ti -1,5-cyclooctadiene)tetrakis(methylhydra-zine)-, bis[tetraphenylborate(l-)],... 

C66H5gBBrCoOP3, Bromocarbonyl-1,1,1-tris(diphenylphosphinomethyl) ethanecobalt (II ) tetraphenylborate, 46B, 1307 Cs sHe 2BBrFePi, Bromo(tr is (2-dipheny Iphosphi noethyl )phosphine) iron-(II) tetrafluoroborate, 44B, 1079... 

Cg gHg 3BFeP4S, Thiolo(tris(2-diphenyIphosphinoethy1)phosphine)iron-(II) tetraphenylborate, 43B, 1473... 

CggHg3BNiP, S, Thiolo(tris(2-diphenylphosphinoethyl)phosphine)nickel-(II) tetraphenylborate, 42B, 1000 43B, 1473 Cg gHg 2B2Ni,Oi 2p Ru, trans-Bis (acetone hydrazone)tetrakis( trimethyl-phosphite) rutheniumdl) bis(tetraphenylborate), 40B, 1066 CssHg2Fe2NftNa20i8 2 Sodium di(M diphenylphosphido)-bis(tricarbonyl-iron) 1,l0-diaza-4,7,13,16,21,24-hexaoxabicyclo[8.8.8]hexacosane, 45B, 1384... 

Cg gHg 11B2P6PCI3S2, Bis[ (Ma-sulf ido) tris( trimethylphosphine) Itripallad-ium(ll) bis(tetraphenylborate), 46B, 1307 Cg7Hgi,BBrCl2FePi, Bromo(hexaphenyl-1,4,7,10-tetraphosphadecane)iron-... 

In another version of this procedure the nonionic surfactant was first extracted batch-wise with sodium tetraphenylborate into 1,2-dichloroethane. The tetraphenylborate in the isolated organic phase was then titrated with a cationic surfactant, using Victoria Blue B as indicator (70). This titration can also be performed to an electrochemically detected end point. In this version, an excess of anionic surfactant is added to the cationic complex formed by the ethoxylated nonionic surfactant and potassium ion. The ion pair is extracted into dichloroethane, separated from the initial aqueous phase, then titrated with cationic surfactant in the presence of additional water. The ion pair of the anionic surfactant and Fe(II)(l,10-phenanthroline)3 is added as indicator. The end point of the titration is indicated when the last of the anionic surfactant is complexed by the cationic titrant, causing the iron-phenanthroline cation to migrate to the aqueous phase, where it is detected as a change in potential at a platinum electrode (71). 

Amine oxides have cationic properties at low pH and so can be titrated with anionic reagents according to the procedures developed for cationic surfactants. Titrations with tetraphenylborate (81) and with dodecylsulfate (82) have been demonstrated, using a potentiometric end point. A turbidimetric end point has also been demonstrated (28). An am-perometric end point may be used in a two-phase system with dodecylsulfate titrant, if a suitable cationic indicator is added such as the iron(II) 1,10-phenanthroline complex (83). Long-chain amines, including any unreacted amine from synthesis of the amine oxide, will quantitatively interfere. 

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