Voltammetric and Morphological Characterization of Heteropolyanions and Copper Co-Electrodeposition by In Situ AFM

The electrodeposition of three different heteropolyoxometalates:(HPOM)(NH₄)₃[RhMo₆O₁₈(OH)₆]· 7 H₂O, HPOM (1), Cu(II)(NH₄)[RhMo₆O₁₈(OH)₆]· 7 H₂O, HPOM (2) and Cu(II)NH₄[CoMo₆O₁₈(OH)₆]· 7 H₂O HPOM (3) was studied by in situ atomic force microscopy (AFM) and cyclic voltammetry. It was found that the voltammetric response of compounds 2 and 3 show the deposition of the copper countercation as well as the simultaneous reduction of the corresponding heteropolyanion (HPA). AFM was used to monitor the in situ film formation of the electroreduced species on the working electrode surface. The AFM images show important differences in the film texture when copper is present in the complex.     

Metallkomplexe mit biologisch wichtigen Liganden. CXXIII. Darstellung von Isophthaloyl‐ und Terephthaloyl‐di‐[(β,γ,δ)‐amino‐α‐aminocarboxylat]‐verbrückten zweikernigen Ruthenium‐, Rhodium‐ und Iridium‐Halbsandwich‐Komplexen

The reaction of the Cu(II) bis N,O‐chelate‐complexes of L‐2,4‐diaminobutyric acid, L‐ornithine and L‐lysine {Cu[H₂N–CH(COO)(CH₂)_nNH₃]₂}²⁺(Cl^–)₂ (n = 2–4) with terephthaloyl dichloride or isophthaloyl dichloride gives the polymeric complexes {‐OC–C₆H₄–CO–NH–(CH₂)_n–CH(nh₂)(COO)Cu(OOC)(NH₂)CH–CH₂)_n–NH‐}_x 1 – 5 . From these the metal can be removed by precipitation of Cu(II) with H₂S. The liberated ω,ω′‐N,N′‐diterephthaloyl (or iso‐phthaloyl)‐diaminoacids 6 – 10 react with [Ru(cymene)Cl₂]₂, [Ru(C₆Me₆)Cl₂]₂, [Cp*RhCl₂]₂ or [Cp*IrCl₂]₂ to the ligand bridged bis‐amino acidate complexes [L_n(Cl)M–(OOC)(NH₂)CH–(CH₂)_nNH–CO]₂–C₆H₄ 11 – 14 .     

A first mixed heteropentametallic transition metal complex: Synthesis and characterisation

The synthesis and characterisation of a novel [(η²-dppf)(η⁵-C₅H₅)Ru(CC)-1,4-(C₆H₄)PPh₂–Au–CC-bipy({[Ti](μ-σ,π-CCSiMe₃)₂}Cu)]PF₆ (dppf = 1,1′-bis(diphenylphosphino)ferrocene) is reported in which five different transition metals (Fe–Ru–Au–Cu–Ti) are linked by carbon-rich organic bridging units.     

CuII Pyrazolyl-Benzimidazole Dinuclear Complexes with Remarkable Antioxidant Activity

Three dinuclear coordination complexes generated from 1-n-butyl-2-((5-methyl-1H-pyrazole-3-yl)methyl)-1H-benzimidazole ( L ), have been synthesized and characterized spectroscopically and structurally by single crystal X-ray diffraction analysis. Reaction with iron(II) chloride and then copper(II) nitrate led to a co-crystal containing 78 % of [Cu(NO₃)(μ-Cl)( L’ )]₂ ( C₁ ) and 22 % of [Cu(NO₃)(μ-NO₃)( L’ )]₂ ( C₂ ), where L was oxidized to a new ligand L^’ . A mechanism is provided. Reaction with copper chloride led to the dinuclear complex [Cu(Cl)(μ-Cl)( L) ]₂ ( C₃ ). The presence of N−H⋅⋅⋅O and C−H⋅⋅⋅O intermolecular interactions in the crystal structure of C₁ and C₂ , and C−H⋅⋅⋅N and C−H⋅⋅⋅Cl hydrogen bonding in the crystal structure of C₃ led to supramolecular structures that were confirmed by Hirshfeld surface analysis. The ligands and their complexes were tested for free radical scavenging activity and ferric reducing antioxidant power. The complex C₁ / C₂ shows remarkable antioxidant activities as compared to the ligand L and reference compounds.     

Novel promotional effect of yttrium on Cu–SAPO-34 monolith catalyst for selective catalytic reduction of NOx by NH3 (NH3-SCR)

Cu–SAPO-34 and CuY–SAPO-34 catalysts for NH₃-SCR were prepared by the wet-impregnation method. XRD, UV–vis DRS, ESR and NH₃-TPD results showed that the introduction of Y effectively improved the dispersion of copper species, increased the amount of isolated copper ions and enhanced the acid density. In addition, the activity test, NH₃-TPD and TGA results reflected that the CuY–SAPO-34 catalyst showed better C₃H₆ oxidation activity, lower dropping degree of acid sites after C₃H₆/O₂ treatment and less adsorption of C₃H₆/O₂ than Cu–SAPO-34 catalyst. Therefore, the addition of Y promoted the NH₃-SCR performance and the hydrocarbon (HC) resistance of Cu–SAPO-34 catalyst.     

Copper Complexes Obtained from the Schiff Base of Quinoline-2-Aldehyde and Aliphatic Diamines

Schiff base bis (2— quinolidene)- diamine gives a purple-red complex with copper ions with a λ_max at 530 mμ. The optimum pH for production of this complex is approximately 9.5. None of the metallic ions of the analytical groups II and III give rise to red complexes with the above Schiff base. Manganous (Mn²⁺) and stannous (Sn²⁺)ions as well as reducing agents such as hydrazine or hydroxylamine exert a catalytic effect on the rate of formation of these copper complexes. The thermal stability of the copper complex formed from the Schiff bases (2-quinoline-aldehyde with NH₂-(CH₂)_n-NH₂) is greater for diamine for which n = 4–6 than for n = 2–3.     

Mononuclear versus dinuclear palladacycles derived from 1,3-bis(N,N-dimethylaminomethyl)benzene: Structures and catalytic activity

Mononuclear and dinuclear palladacycles derived from 1,3-bis(N,N-dimethylaminomethyl)benzenes, [{Pd(Cl)}2,6-(Me₂NCH₂)₂C₆H₃] (1) and [1-{Pd(H₂O)(Py)}-5-{Pd(OTf)(Py)-2,4-(Me₂NCH₂)₂C₆H₂]-(OTf) (2), were synthesized and their structures were fully characterized. Complex 1 is a pincer complex with η³-mer NCN phenyl backbone, complex 2 is a bispalladium(II) complex with 1,2- and 4,5- two C,N-ortho phenyl backbone. Whereas the pincer complex 1 acted as a poor catalyst on methanolysis of fenitrothion, complex 2 demonstrated high catalytic activity in the same reactions, but there is no synergetic effect between two palladium ions. The results clearly indicate that a dissociable co-ligand in the palladacycle compounds significantly promotes the catalytic methanolysis.     

The retention of copper ions by AlPO4-5/VAPO-5 and their effect on reactant access

The reaction of copper salts with AlPO₄-5 or V^v-VAPO-5 under acidic (CuCl₂, pH adjusted to 2) but especially basic conditions (Cu(NH₃) ₄ ²⁺ , pH adjusted to 9) gives ion incorporations greater than expected by a simple ion exchange mechanism (both AlPO₄-5 and V^v-VAPO-5 could be expected to have no cation exchange capacity). Ion incorporation is proposed to occur initially at defect sites, and examination of the ESR spectrum of a dehydrated, evacuated CuCl₂-exchanged AlPO₄-5 shows that these defect sites give rise to a number of unique environments upon Cu^II incorporation. The CuCl₂-exchanged VAPO-5 retains a significant toluene accessibility to the V^v sites in the VAPO-5. However, the toluene accessibility in the Cu(NH₃) ₄ ²⁺ -exchanged VAPO-5 is significantly reduced and we propose this is due to a combination of the presence of crystalline CuO and structural collapse from reaction with base (NH₄OH). The ability of treatment with base (NH₄OH, pH 13) to restrict access of toluene to the V^v sites of the original VAPO-5 was verified in a separate experiment.     

Kinetics of ligand exchange reaction of Cu(II)-ammine complex with poly(vinyl alcohol) in aqueous solution

The kinetics of the ligand exchange reaction of the Cu(II)-ammine complex with poly(vinyl alcohol) (PVA) has been studied by a stopped-flow method at pH 9–10, at μ=0.1 (NH₄Cl) and at 25°C. The reaction is initiated by the formation of unstable [Cu(NH₃)₃]²⁺ by the attack of H⁺ on Cu(II)-ammine complex, and proceeds through the mixed complex {[Cu(NH₃)₃(O?PVA)]²⁺}. This step may be rate-determining, followed by a rapid reaction. Finally, the Cu(II) ion is taken up by PVA. The rate is given by d[Cu(II)?PVA]/dt=k[H⁺]{[Cu(NH₃)₄]²⁺}[PVA]/[NH₄Cl], where k=k₁ + k′₂[H⁺], k₁=4.25× 10s^?1 and k′₂=5.20× 10¹¹l mol^?1s^?1.     

Novel Copper(II) Complexes of <Emphasis Type="Italic">N</Emphasis>-Phenylanthranilic Acid Containing Ethanol and Hydroxo Ligands

The complexes, tetra-μ-[2-(phenylamino)benzoato](O,O′)-bis[(ethanol)copper(II)] (1) and di-μ-[2-(phenylamino)benzoato](O,O′)-bis[(hydroxo)copper(II)] (2), were synthesized by the reaction of N-phenylanthranilic acid and CuCl₂·2H₂O in an ethanol water mixture. In complex 1, each Cu(II) atom, which is in a slightly distorted square pyramidal environment, is coordinated equatorially by four N-phenylanthranilate O-atoms and axially by the ethanol O-atoms. In complex 2, [Cu₂(C₆H₅NHC₆H₄COO)₂(OH)₂], each Cu(II) atom, which is in tetrahedral environment, is coordinated by two N-phenylanthranilate O-atoms and hydroxo ligands. The crystal structure (monoclinic, P21/c space group) of complex 1 comprises a dinuclear [Cu₂(C₆H₅NHC₆H₄COO)₄(CH₃CH₂OH)₂] species and the dimer is located on a crystallographic inversion centre. The Cu(II) ions, 2.591(2) Å apart, are bridged by the carboxylate groups of four N-phenylanthranilate ligands. The complex molecules show three-dimensional supramolecular networks by O–H···O, C–H···O and C–H···π interactions.     

Synthesis and characterization of aluminum citrate compounds and evaluation of their influence on the formation of hydrogels based on polyacrylamide

Aluminum citrate is used as a conformance control agent to improve oil production and excess water production. This paper discusses the formation of mono and polynuclear aluminum species from the synthesis of aluminum citrate and evaluates these compounds as crosslinkers in hydrogels for conformance control. The products obtained from the synthesis were characterized by Fourier-transform infrared spectrometry (FTIR), elemental analysis (CHN), scanning electron microscopy (SEM), and inductively coupled plasma–optical emission spectrometry (ICP-OES). The FTIR analyses indicated the presence of mononuclear aluminum citrate complexes at pH 3 and polynuclear species starting at pH 4. These results were corroborated by CHN and ICP-OES techniques, which revealed the variation of carbon, oxygen, hydrogen, and alumina precipitate levels as functions of pH variation. The focus of the study was to assess how these crosslinking agents perform in hydrogel formation under reservoir conditions. Rheological analysis showed that the values of tan (delta) of the hydrogel synthesized with aluminum citrate at pH 6 were lower than 0.1, indicating strong gels, while at pH 9, the values were above 0.1, indicating weak gels. These results are in agreement with those obtained by FTIR, which showed that at pH 6, the structures of the aluminum citrate complex were probably in the form [Al₃(C₆H₅O₇)₃(OH)₄(H₂O)]⁴⁻. This structure appears to allow easier access to the aluminum orbital for the crosslinking process compared to the gel composed of aluminum citrate synthesized at pH 9 [Al₃(C₆H₆O₇)₃(OH)₄(H₂O)₅]⁴⁻.

     

Mechanistic in situ High‐Pressure NMR Studies of Benzene Hydrogenation by Supramolecular Cluster Catalysis with [(η6‐C6H6)(η6‐C6Me6)2Ru3(μ3‐O)(μ2‐OH)(μ2‐H)2][BF4]

In situ high‐pressure NMR spectroscopy of the hydrogenation of benzene to give cyclohexane, catalysed by the cluster cation [(η⁶‐C₆H₆) (η⁶‐C₆Me₆)₂Ru₃(μ₃‐O)(μ₂‐OH)(μ₂‐H)₂]⁺ 2 , supports a mechanism involving a supramolecular host‐guest complex of the substrate molecule in the hydrophobic pocket of the intact cluster molecule.     

Reaction of Aryl Iodides with (PCP)Pd(II)—Alkyl and Aryl Complexes: Mechanistic Aspects of Carbon—Carbon Bond Formation

The reaction of the PCP-type complex Pd(Me){2,6-(ⁱPr₂PCH₂)₂C₆H₃}( 3 ) with phenyl iodide results in the formation of Pd(I){2,6-(ⁱPr₂PCH₂)₂C₆H₃} ( 5 ), methyl iodide, toluene, and biphenyl. Formation of Pd(Ph){2,6-(ⁱPr₂PCH₂)₂C₆H₃}( 4 ) is observed during the reaction by ³¹P NMR. Reaction of 4 with aryl iodides results in the formation of 5 and Ph–Ph, Ph–Ar, and Ar–Ar, products indicative of a radical reaction. Under pseudo-first-order conditions, the rates of the reactions follow the order p-OMe > p-Me > H > p-NO₂ > m-Cl. The reaction is likely to involve electron transfer from 4 to the aryl iodide followed by fast decomposition of a postulated radical cation [Pd(Ph){2,6-(ⁱPr₂PCH₂)₂C₆H₃}]^+. ( 4 ^+.) to give a phenyl radical and [Pd{2,6-(ⁱPr₂PCH₂)₂C₆H₃}]⁺ ( 6 ⁺). Facile decomposition of the aryl iodide radical anion generates an aryl radical and I⁻. Recombination of aryl radicals gives rise to mixed biaryls, and 6 ⁺ combines with I⁻ to give 5 .     

Open-chain hemiketal is stabilized by coordination to a copper (II)

The hemiketal complex [Cu{NH₂C(Me)₂C(Ph)(OMe)O}₂] (1) was generated by the reaction of [Cu(NCMe)₄](BF₄) and 4 equivs of 2,2-dimethyl-3-phenyl-2H-azirine in the presence of NCNMe₂ in wet MeOH and isolated in 92% yield. In 1, the in situ formed hemiketal NH₂C(Me)₂C(Ph)(OMe)OH in its deprotonated form is stabilized due to chelation to copper(II). In the X-ray structure of 14MeOH, the intermolecular hydrogen bonding was detected between O and N atoms of the organic ligand and the HO group of solvated MeOH as well as between two molecules of the solvated MeOH. Three types of hydrogen bonds in the obtained structure were studied by the DFT calculations (M06/6-31 ++G** level of theory, MDF10 pseudopotentials on the Cu atoms) and topological analysis of the electron density distribution within the formalism of Bader's theory (QTAIM method). Estimated strength of these non-covalent interactions is 3–9 kcal/mol.     

Micellar association in simultaneous presence of organic salts/additives

Viscosity measurements under Newtonian flow conditions had been performed on cetyltrimethylammonium bromide (CTAB) aqueous solutions in the combined presence of sodium salts of aromatic acids (sodium salicylate, NaSal; sodium benzoate, NaBen; sodium anthranilate, NaAn) and organic additives (1-hexanol, C₆OH; n-hexylamine, C₆NH₂) at 30°C. On addition of C₆OH or C₆NH₂, the viscosity of 25 mM CTAB solution remained nearly constant without salt as well as with a lower salt concentration. This is due to low CTAB concentration which is not sufficient to produce structural changes in this concentration range of salts. However, as the salt concentration was increased further, the effect of C₆OH/C₆NH₂ addition was different with different salts: The viscosity first increased; then a decrease was observed with the former while with C₆NH₂ a decrease followed by constancy appeared in plots of relative viscosities (η _r ) vs. organic additive concentrations. At further higher salt concentration, the magnitude of η _r was much higher. The viscosity increase is explained in terms of micellar growth and the decrease in terms of swollen micelle formation (due to interior solubilization of organic additive) or micellar disintegration (due to formation of water + additive pseudophase).     

Ammonium tris-oxalatoferrate(III) as a source of metalloligand in direct synthesis of Cu/Fe coordination polymer

It has been shown that one-pot reaction of copper powder, ammonium tris-oxalatoferrate(III) (NH₄)₃[Fe(C₂O₄)₃]·3H₂O as a source of metalloligand, and ethylenediamine (en) leads to the formation of heterobimetallic complex (NH₄)[Cu(en)₂Fe(C₂O₄)₃]?2dmso (1). This complex has been characterised by elemental analysis, IR spectroscopy and single crystal X-ray crystallography. Crystal structure analysis reveals that 1 consists of [Cu(en)₂Fe(C₂O₄)₃]^? anionic chains with regularly alternated [Cu(en)₂]²⁺ and [Fe(C₂O₄)₃]^3? moieties. Magnetic susceptibility measurements indicate absence of a significant exchange interaction between the metal units. The polycrystalline X-band EPR spectrum of 1 exhibits broad line characteristic of Fe(III) centers, whereas the signals observed in EPR spectrum of frozen dmf solution of 1 are distinctly associated with zero field splitting in the spin states of rhombically distorted Fe(III) centers, non interacting with Cu(II) centers.     

Synthesis,structure and characterization of (NH4)2[Cu2(H2O)4(NH3CH2COO)2(NH2CH2COO)2]H2V10O28·6H2O

The decavanadate with a novel glycine–glycinato complex of copper (II) in the cationic part, (NH₄)₂[Cu₂(H₂O)₄(NH₃CH₂COO)₂(NH₂CH₂COO)₂]H₂V₁₀O₂₈·6H₂O (1), has been prepared and characterized by elemental analysis, infrared and EPR spectroscopies. The triplet X band EPR spectrum of powdered sample evidenced magnetic interaction between the Cu(II) atoms in the dimeric unit which is probably realized through the bridging water molecules in this part of the complex. A single crystal X-ray diffraction study revealed that the structure of 1 contains cationic copper complex with a rare Cu(H₂O)₂Cu double bridge. In this cation, a simultaneous bidentate N, O– and monodentate O– coordination of glycine to the same central atom was observed for the first time.     

Approaches to the Chemical,Electrochemical, and Photochemical Activation of Carbon Dioxide by Transition Metal Complexes

The activation of CO₂ by chemical, electrochemical, and photochemical means is discussed. Binuclear transition metal complexes mediate oxygen atom transfers from CO₂ by three distinct chemical pathways: (i) deoxygenation of CO₂, (ii) multiple bond metathesis, and (iii) disproportionation. The complex Ir₂ (μ-CNR)₂(CNR)₂(dmpm),(dmpm = bis(dimethylphosphino)methane) undergoes double cycloaddition of CO₂ to its μ-CNR ligands. A subsequent reaction produces the bis(carbamoyl) complex [Ir₂(μ-CO)(μ-H)(CONHR)₂(CNR)₂(dmpm)₂]Cl. Isotope labelling studies show that the μ-CO ligand results from net deoxygenation of CO₂. In contrast, the binuclear nickel complex Ni₂(μ-CNMe)(CNMe)₂(dppm)₂ (dppm = bis-(diphenylphosphino)methane) reacts with liquid CO₂ to give the tricarbonyl complex Ni₂(μ-CO)(CO)₂(dppm)₂. Isotope labelling indicates that the carbonyl ligands are not derived from CO₂ deoxygenation, but from C/CO triple bond metathesis. The reaction of CO₂ with the Ir(0) complex Ir₂(CO)₃(dmpm)₂ leads to CO₂ disproportionation by formation of the carbonate, Ir₂(CO₃)(CO)₂(dmpm)₂, and tetracarbonyl, Ir₂(CO)₄(dmpm)₂, complexes. The complex Ir₂(CO₃)(CO)₂ (dmpm)₂ undergoes reversible O-atom transfers from its carbonate ligand. The electrochemical activation of CO₂ by the binuclear Ni₂(μ-CNMe)(CNMe)₂(dppm)₂ and trinuclear [Ni₃(μ-CNMe)(μ-I)(dppm)₃][PF₆] species is described. The triangular nickel complex [Ni₃(μ₃-CNMe)(μ₃-I)(dppm)₃][PF₆] is an electrocatalyst for the reduction of CO₂. The cluster exhibits a reversible single electron reduction at E⁰(^+/0) = −1.09 V vs. Ag/AgCl. In the presence of CO₂, the cluster reduces CO₂ by an EC' electrochemical mechanism. The reduction products correspond to the disproportionation and H-atom abstraction products of CO₂^*−, with a partitioning ratio of 10:1. Isotope labelling studies with ¹³CO₂ indicate that ¹³CO₂^*− disproportionation produces ¹³CO and ¹³CO₃²⁻. Studies of the photochemical activation of CO₂ by Ni₂(μ-CNMe)(CNMe)₂(dppm)₂ are described. The bimolecular photochemical addition of CO₂ to the complex was examined by laser transient absorbance spectroscopy. Photolysis at 355nm in the presence of CO₂ (1 atm) leads to cycloaddition of CO₂ to the μ-CNMe ligand and the complex Ni₂(μ-CN(Me)C(O)O)(CNMe)₂(dppm)₂ with Φ₃₅₅=0.05. The triplet excited state of Ni,(μ-CNMe)(CNMe)₂(dppm)₂ was determined to react with CO₂ with the bimolecular reaction rate constant k = 1 × 10⁴ M⁻¹ s⁻¹. Bridging ligand substituent effects and solvent dependence of the lowest energy electronic absorption spectral bands of the series of complexes, Ni₂(μ-L)(CNMe)₂(dppm)₂, L = CNMe, CNC₆H₅, CN-p-C₆H₄Cl. and CN-p-C₆H₄Me, confirm the assignment of di-metal to bridging ligand charge transfer (M₂→μ-LCT). This assignment is supported by results of extended Hückel calculations which indicate a LUMO of predominantly μ-isocyanide π* character. A systematic study of the nature of the lowest excited states of related d¹⁰–d¹⁰ binuclear complexes of the type Ni₂(μ-L)(CNMe)₂(dppm)₂, where L = CNMe(Ph)⁺, CNMe₂⁺, CNMe(C₅H₁₁)⁺, CNMe(H)⁺, CNMe(CH₂C₆H₅)⁺, and NO⁺ reveals dramatic differences in the lowest excited states of the three classes of complexes: μ-isocyanide, μ-aminocarbyne, and μ-nitrosyl. Spectroscopic and extended Hückel MO studies confirm that the μ-isocyanide complexes are characterized by di-metal to bridging ligand charge transfer (M₂ → μ-LCT) excited states. However, the μ-aminocarbyne and μ-nitrosyl complexes exhibit bridging ligand to metal charge transfer (μ-L→M₂) and intraligand (IL) lowest excited states, respectively.     

Deposition of diamond from a plasma jet with phenol as the carbon source

The deposition of diamond on a molybdenum substrate was studied in an Ar–H₂ plasma jet adding phenol (C₆H₅OH) as a carbon source and was compared with adding benzene (C₆H₆) to examine the effect of OH species on diamond deposition. Better faceted and larger crystal size diamond was deposited from the Ar–C₆H₅OH–H₂ plasma jet than from the Ar–C₆H₆–H₂ plasma jet. Furthermore, the amount of co-deposited graphite and/or amorphous carbon in the deposit from the Ar–C₆H₅OH–H₂ plasma jet was smaller than that in the deposit from the Ar–C₆H₆–H₂ plasma jet. At the beginning of the exposure to the Ar–C₆H₅OH–H₂ plasma jet, in which OH radicals were identified, the surface of the substrate was slightly oxidized. Oxide formation on the surface of the substrate by reaction with OH radicals would contribute to the purification and increase of crystal size in the diamond deposition with an Ar–C₆H₅OH–H₂ plasma jet.     

Enhanced Hydrogenation Activity and Recycling of Cationic Rhodium Diphosphine Complexes through the Use of Highly Fluorous and Weakly‐Coordinating Tetraphenylborate Anions

The effect of the nature of the anion on the performance of ionic rhodium catalysts has received little attention. Herein it is shown that the use of highly fluorous tetraphenylborate anions can enhance catalyst activity in both conventional and fluorous media. For hydrogenation catalysts of the type [Rh(COD)(dppb)][X] {COD=1,5‐cis,cis‐cyclooctadiene; dppb=1,4‐bis(diphenylphosphino)butane; X=BF₄⁻ ( 1a ), [BPh₄]⁻ ( 1b ), [B{C₆H₄(SiMe₃)‐4}₄]⁻ ( 1c ), [B{C₆H₃(CF₃)₂‐3,5}₄]⁻ ( 1d ), [B{C₆H₄(SiMe₂CH₂CH₂C₆F₁₃)‐4}₄]⁻ ( 1e ), [B{C₆H₄(C₆F₁₃)‐4}₄]⁻ ( 1f ) and [B{C₆H₃(C₆F₁₃)₂‐3,5}₄]⁻ ( 1 g )} the activity towards the hydrogenation of 1‐octene in acetone increased in the order 1c < 1b < 1e < 1a < 1d ~ 1f < 1g with 1g being twice as active as the commonly applied 1a . Despite the fluorophilic character introduced by the substituted tetraarylborate anions, the presence of some perfluoroalkyl‐substituents in the cation was still required for achieving high partition coefficients. Therefore, [Rh(COD)(Ar₂PCH₂CH₂PAr₂)][X] {Ar=C₆H₄(SiMe₂CH₂CH₂C₆F₁₃)‐4, X=[B{C₆H₃(C₆F₁₃)₂‐3,5}₄]⁻ ( 3f ); Ar=C₆H₄(SiMe(CH₂CH₂C₆F₁₃)₂)‐4 and X=[B{C₆H₄(C₆F₁₃)‐4}₄]⁻ ( 2g )} were prepared, which were active in the hydrogenation of 1‐octene, 2g even more so than 3f . Both these highly fluorous catalysts could be recycled with 99% efficiency through fluorous biphasic separation, whereas the corresponding BF₄⁻ complex of 2g ( 2a ) did not show any affinity for the fluorous phase.