Fluorido Complexes Research Articles

Activation of SO2F2 at a Rhodium PNP Pincer Complex: Ligand Supported S-F Bond Cleavage to Generate NSO2F Derivatives.

The κ2-(P,N)-phosphine ligand precursor NH(CH2CH2PCy2)2 can be used for the synthesis of the rhodium(I) complex [Rh(CO){ĸ3-(P,N,P)-Cy2PC2H4NHC2H4PCy2}][Cl] (1). The deprotonated complex [Rh(CO){ĸ3-(P,N,P)-Cy2PC2H4NC2H4PCy2}] (2) shows a cooperative reactivity of the PNP ligand in the activation reaction of SO2F2 to yield the rhodium fluorido complex trans-[Rh(F)(CO){ĸ2-(P,P)-Cy2PC2H4N(SO2F)C2H4PCy2}]2 (3) by S-F bond cleavage. It is remarkable that no reaction was observed when 3 was treated with hydrogen sources e. g. dihydrogen, organosilicon compounds such as triethylsilane or TMS-CF3 and different fluorine sources such as SF4 or Selectfluor®. However, the treatment of complex 3 with XeF2 in the presence of CsF resulted in the formation of the unique fluorido rhodium(III) complex cis,trans-[Rh(F)3(CO){ĸ2-(P,P)-Cy2PC2H4N(SO2F)C2H4PCy2}]2 (4). In the presence of pyridine(HF)X or BF3 the fluorido complex 3 converted into the dicationic complexes [Rh(CO){ĸ2-(P,P)-Cy2PC2H4N(SO2F)C2H4PCy2}]2[XF]2, X=HF (5) or BF3 (6), respectively.

Fluoride Abstraction Induced by Tris(pentafluoroethyl)difluorophosphorane: A Convenient Way to Synthesize Cationic N-Heterocyclic Carbene- and Cyclic (Alkyl)(amino)carbene-Ligated Copper Alkyne and Arene Complexes.

We herein report the convenient synthesis of different N-heterocyclic carbene (NHC)- and cyclic (alkyl)(amino)carbene (cAAC)-ligated copper cations using the weakly coordinating tris(pentafluoroethyl)trifluorophosphate counterion (FAP anion, [(C2F5)3PF3]-). The reaction of the fluorido complexes [(carbene)CuF] (carbene = NHC, cAACMe) 2a-2f and the tris(pentafluoroethyl)difluorophosphorane (C2F5)3PF2 in the presence of alkynes or arenes led to fluoride transfer from Cu to the phosphorane with formation of the cationic transition metal complexes [(carbene)Cu(L)]+ and the weakly coordinating counteranion [(C2F5)3PF3]- (FAP). Using this method, the complexes [(IDipp)Cu(L)]+FAP- (IDipp = 1,3-bis(2,6-di-iso-propylphenyl)-imidazolin-2-ylidene; L = PhC≡CPh, 4d; PhC≡CMe, 5d), [(cAACMe)Cu(L)]+FAP- (cAACMe = 1-(2,6-di-iso-propylphenyl)-3,3,5,5-tetramethyl-pyrrolidin-2-ylidene; L = PhC≡CPh, 4f; PhC≡CMe, 5f), [(SIDipp)Cu(C6Me6)]+FAP- (6e), (SIDipp = 1,3-bis(2,6-di-iso-propylphenyl)-imidazolidine-2-ylidene), and [(cAACMe)Cu(C6Me6)]+FAP- (6f) have been synthesized and characterized. The complexes [(IDipp)Cu(C6Me6)]+FAP- (6d) and [(cAACMe)Cu(C6Me6)]+FAP- (6f) have been used as catalysts for the copper(I)-catalyzed cycloaddition of benzyl azide to terminal alkynes.

Indolyl Phosphine Nickel(II) Fluorido Complexes: Synthesis and Intermediates in Suzuki–Miyaura Cross‐Coupling Reactions

AbstractThe C−F bond activation of pentafluoropyridine and 2,3,5,6‐tetrafluoropyridine at [Ni(cod)2] (cod=1,5‐cyclooctadiene) in the presence of the phosphine PPh2(Ind) (Ind=3‐methyl‐2‐indolyl) led to the formation of the nickel(II) fluorido bis(phosphine) complexes trans‐[Ni(F)(2‐C5NF4){PPh2(Ind)}2] and trans‐[Ni(F)(2‐C5HNF3){PPh2(Ind)}2]. The complexes are characterized by the presence of intramolecular hydrogen bonds between the NH group of the phosphine ligands and the fluorido ligand. Stochiometric model reactions of nickel(II) fluorido complexes with PhB(OH)2 revealed that the former can be considered as intermediates in Suzuki–Miyaura cross coupling reactions. Catalytic experiments were attempted using 10 mol‐% of trans‐[Ni(F)(2‐C5NF4){PPh2(Ind)}2] as catalyst and the activities of the PPh2(Ind) complex were compared to the ones of an analogous nickel(II) fluorido complex, bearing PPh3 instead of PPh2(Ind) as ligands. The latter exhibited a somewhat lower catalytic activity suggesting a slight influence of the H‐bonds in the outer coordination sphere.

Hydrogen Bonding in Platinum Indolylphosphine Polyfluorido and Fluorido Complexes.

The reaction of the Pt complexes cis-[Pt(CH3 )(Ar){Ph2 P(Ind)}2 ] (Ind=2-(3-methyl)indolyl, Ar=4-tBuC6 H4 (1 a), 4-CH3 C6 H4 (1 b), Ph (1 c), 4-FC6 H4 (1 d), 4-ClC6 H4 (1 e), 4-CF3 C6 H4 (1 f)) with HF afforded the polyfluorido complexes trans-[Pt(F(HF)2 )(Ar){Ph2 P(Ind)}2 ] 2 a-f, which can be converted into the fluoride derivatives trans-[Pt(F)(Ar){Ph2 P(Ind)}2 ] (3 a-f) by treatment with CsF. The compounds 2 a-f and 3 a-f were characterised thoroughly by multinuclear NMR spectroscopy. The data reveal hydrogen bonding of the fluorido ligand with HF molecules and the indolylphosphine ligand. Polyfluorido complexes 2 a-f show larger |1 J(F,Pt)|, but lower 1 J(H,F) coupling constants when compared to the fluorido complexes 3 a-f. Decreasing 1 J(P,Pt) coupling constants in 2 a-f and 3 a-f suggest a cis influence of the aryl ligands in the following order: 4-tBuC6 H4 (a) ≈4-CH3 C6 H4 (b)<Ph (c)≪4-FC6 H4 (d)<4-ClC6 H4 (e)<4-CF3 C6 H4 (f). In addition, the larger cis influence of aryl ligands bearing electron-withdrawing groups in the para position correlates with decreasing magnitudes of |1 J(F,Pt)| coupling constants. The interpretation of the experimental data was supported by quantum-chemical DFT calculations.

Conversion of a AuI Fluorido Complex into an N‐Fluoroamido Derivative: N−F versus Au−N Reactivity

AbstractThe AuI complex [Au{N(F)SO2Ph}(SPhos)] (SPhos=dicyclohexyl(2′,6′‐dimethoxy[1,1′‐biphenyl]‐2‐yl)phosphane) (2) bearing a fluoroamido ligand has been synthesized by reaction of the fluorido complex [Au(F)(SPhos)] (1) with NFSI (NFSI=N‐fluorobenzenesulfonimide). A reaction with CO resulted in an unprecedented insertion into the N−F bond at 2. With the carbene precursor N2CH(CO2Et) N−F bond cleavage gave the Au−F bond insertion product [Au{CHF(CO2C2H5)}(SPhos)] (7). The presence of CNtBu led to Au−N cleavage at 2 and concomitant amide formation to give the cationic complex [Au(CNtBu)(SPhos)][N(F)SO2Ph)] (5), which reacted further to give FtBu as well as the cyanido complex [Au(CN)(SPhos)] (6). These results led to the development of a process for the amination of electrophilic organic substrates by transfer of the fluoroamido group NF(SO2Ph)−.

Conversion of a AuI Fluorido Complex into an N-Fluoroamido Derivative: N-F versus Au-N Reactivity.

The AuI complex [Au{N(F)SO2 Ph}(SPhos)] (SPhos=dicyclohexyl(2',6'-dimethoxy[1,1'-biphenyl]-2-yl)phosphane) (2) bearing a fluoroamido ligand has been synthesized by reaction of the fluorido complex [Au(F)(SPhos)] (1) with NFSI (NFSI=N-fluorobenzenesulfonimide). A reaction with CO resulted in an unprecedented insertion into the N-F bond at 2. With the carbene precursor N2 CH(CO2 Et) N-F bond cleavage gave the Au-F bond insertion product [Au{CHF(CO2 C2 H5 )}(SPhos)] (7). The presence of CNtBu led to Au-N cleavage at 2 and concomitant amide formation to give the cationic complex [Au(CNtBu)(SPhos)][N(F)SO2 Ph)] (5), which reacted further to give FtBu as well as the cyanido complex [Au(CN)(SPhos)] (6). These results led to the development of a process for the amination of electrophilic organic substrates by transfer of the fluoroamido group NF(SO2 Ph)- .

Hydrogen and Halogen Bonding to Au(I) Fluorido Complexes

AbstractThe hydrogen bonding in the Au(I) complex [Au(F ⋅ HF)(SPhos)] (SPhos=dicyclohexyl(2’,6’‐dimethoxy[1,1’‐biphenyl]‐2‐yl)phosphane) (1 a ⋅ HF) has been analysed by IR and NMR measurements, revealing the formation of an unsymmetrical bifluoride moiety. The data are in excellent agreement with DFT calculations. Comparisons to analogous complexes bearing NHC (NHC=N‐heterocyclic carbene) ligands demonstrated a comparable bonding situation. The identity of the halogen bond in the compound [Au(F ⋅ IC6F5)(SPhos)] (1 a ⋅ IC6F5) in CD2Cl2has been estimated, and van't Hoff data for the equilibrium between [Au(F)(SPhos)] (1 a) and IC6F5with [Au(F ⋅ IC6F5)(SPhos)] are ΔH0=−8.1(3) kJ mol−1and ΔS0=−36(1) J (mol K)−1. The latter are also in agreement with DFT calculations. For all calculations, comparisons between an explicit and implicit solvent model were drawn. Single crystal X‐ray diffraction studies were performed for [Au(F ⋅ 2IC6F5)(BrettPhos)] ⋅ 2IC6F5(BrettPhos=2‐(dicyclohexylphosphino)‐3,6‐dimethoxy‐2’,4’,6’‐triisopropyl‐1,1’‐biphenyl) (1 b ⋅ 4IC6F5) demonstrating the presence of halogen bonds to Au(I) fluorido complexes in the solid state.

Platinum-Catalyzed Hydrofluorination of Alkynes: Hydrogen Bonding to Indolylphosphine Ligands to Provide Fluoride Reactivity.

The reaction of the Pt complexes cis‐[Pt(CH3)2{R2P(Ind)}2] (Ind=2‐(3‐methyl)indolyl, R=Ph (1 a), 4‐FC6H4 (1 b), 4‐CF3C6H4 (1 c)) with HF afforded the fluorido complexes trans‐[Pt(F(HF)2)(CH3){R2P(Ind)}2] 2 a–c, which can be converted into trans‐[Pt(F)(CH3){R2P(Ind)}2] (3 a–c) by treatment with CsF. Addition of 3‐hexyne to 2 a–c gave alkyne complexes trans‐[Pt(C,C‐η2 ‐C2H5 C≡CC2H5)(CH3){R2P(Ind)}2{F(HF)2}] (4 a–c) at which a fluoride is stabilised as polyfluoride in the coordination sphere by hydrogen bonding to the indolyl‐substituted phosphine ligands. Subsequent heating of a solution of 4 a in the presence of PVPHF led to fluoroalkene formation. Selective catalytic hydrofluorination of alkynes to yield (Z)‐fluoroalkenes were developed. The ability of hydrogen bonding to polyfluoride favours the fluorination step as demonstrated by studies with complexes bearing no indolyl groups at the phosphine ligands.

Evaluation for internal consistency in the thermodynamic network involving fluorite, cryolite and villiaumite solubilities and aqueous species at 25°C and 1 bar

AbstractThermodynamic data are constrained by the interrelated thermodynamic equations in addition to the observational measurements and their uncertainties. The consequence is a network of thermodynamic properties that can be evaluated for their internal consistency. In this study, three fluoride minerals that can cause high fluoride concentrations in groundwaters are evaluated for their solubilities and their internal thermodynamic consistency with calorimetric, isopiestic and electrochemical measurements: fluorite, CaF2, cryolite, Na3AlF6, and villiaumite, NaF. This evaluation involves the three solids and 13 aqueous species, the free ions of Ca2+, Na+, Al3+ and F–, and the hydroxido and fluorido complexes of Al3+, and the CaF+ ion pair. For the fluorite–cryolite–villiaumite–aqueous species network, the number of components is minimal, and the solubility studies are mostly of high quality. Re-evaluations of original data using PHREEQC helps to broaden the quantitative evaluation of thermodynamic properties and to resolve apparent discrepancies. A check on this thermodynamic network shows that through a careful appraisal of the literature, a highly consistent set of values can be derived. The resultant infinite-dilution solubility-product constants at 25°C and 1 bar are: for fluorite solubility, logKsp = –10.57 ± 0.08; for cryolite solubility, logKsp = –33.9 ± 0.2; and for villiaumite solubility, logKsp = –0.4981 ± 0.003.

Reactivity of Xantphos-Type Rhodium Complexes Towards SF4 : SF3 Versus SF2 Complex Generation.

S−F‐bond activation of sulfur tetrafluoride at [Rh(Cl)( tBuxanPOP)] (1; tBuxanPOP=9,9‐dimethyl‐4,5‐bis‐(di‐tert‐butylphosphino)‐xanthene) led to the formation of the cationic complex [Rh(F)(Cl)(SF2)( tBuxanPOP)][SF5] (2 a) together with trans‐[Rh(Cl)(F)2( tBuxanPOP)] (3) and cis‐[Rh(Cl)2(F)( tBuxanPOP)] (4) which both could also be obtained by the reaction of SF5Cl with 1. In contrast to that, the conversion of SF4 at the methyl complex [Rh(Me)( tBuxanPOP)] (5) gave the isolable and room‐temperature stable cationic λ4‐trifluorosulfanyl complex [Rh(Me)(SF3)( tBuxanPOP)][SF5] (6). Treatment of 6 with the Lewis acids BF3 or AsF5 produced the dicationic difluorosulfanyl complex [Rh(Me)(SF2)( tBuxanPOP)][BF4]2 (8 a) or [Rh(Me)(SF2)( tBuxanPOP)][AsF6]2 (8 b), respectively. Refluorination of 8 a was possible with the use of dimethylamine giving [Rh(Me)(SF3)( tBuxanPOP)][BF4] (9). A reaction of 6 with trichloroisocyanuric acid (TClCA) gave the fluorido complex [Rh(F)(Cl)(SF2)( tBuxanPOP)][Cl] (2 b) together with chloromethane and SF5Cl.

Au(I) Fluorido Phosphine Complexes: Tools for the Hydrofluorination of Alkynes

AbstractThe reactivity of the Au(I) fluorido complex [Au(F)(SPhos)] (SPhos=dicyclohexyl(2’,6’‐dimethoxy[1,1’‐biphenyl]‐2‐yl)phosphine) (1) towards several alkynes was studied. The formation of fluorovinyl species by formal insertion of the alkyne in the metal‐fluorine bond was observed. Addition of HCl to vinyl complexes resulted in protodeauration and elimination of the hydrofluorinated alkynes. Treatment of1with the terminal alkyne 1‐hexyne resulted in clean formation of the alkynyl complex [Au(C≡CC4H9)(SPhos)] (15), whereas with an excess alkyne hydrofluorination was also observed. Various Au(I) phosphine complexes including1were then compared in their ability to catalyze hydrofluorination reactions of 1‐phenyl‐1‐propyne with Et3N ⋅ 3HF as HF source. Model reactions suggested a reaction mechanism, which imparts a pre‐coordination of an alkyne to a cationic gold center followed by nucleophilic addition of a fluoride. Mechanistic investigations included reactivity studies at [Au(SPhos)][B(C6F5)4)] (17), which was treated with 4‐phenyl‐3‐butyn‐2‐one and TMAF (TMAF=tetramethylammonium fluoride). The reaction led to the formation of the complex [Au(CH3C(O)C=C(F)Ph)(SPhos)] (13), but not the fluorido complex1.

Synthesis, Reactivity, and Bonding of Gold(I) Fluorido-Phosphine Complexes.

Gold(I) fluorido complexes with phosphine ligands have been synthesized from their respective iodido precursors. The bonding situation in comparison between complexes bearing phosphines and N-heterocyclic carbenes (NHCs) was explored quantum-chemically, obtaining similar results for both. Calculations of the 19F NMR chemical shifts match the experimental values well, including the approximately 40 ppm low-field shifts for the phosphine complexes compared to the NHC complexes, in spite of similar negative charges on fluorine. The reactivity of the highly water-sensitive gold(I) fluorido complexes was studied, resulting in substitution at the metal using trimethylsilyl reagents. The compounds studied were characterized using NMR as well as X-ray diffraction methods.

Fluorination Reactions at a Platinum Carbene Complex: Reaction Routes to SF3 , S(=O)F and Fluorido Complexes.

The electron‐rich Pt complex [Pt(IMes)2] (IMes: [1,3‐bis(2,4,6‐trimethylphenyl)‐2‐imidazolinylidine]) can be used as precursor for the syntheses of a variety of fluorido ligand containing compounds. The sulfur fluoride SF4 undergoes a rapid oxidative addition at Pt0 to yield trans‐[Pt(F)(SF3)(IMes)2]. A photolytic reaction of SF6 at [Pt(IMes)2] in the presence of IMes gave the fluorido complexes trans‐[Pt(F)2(IMes)2] and trans‐[Pt(F)(SF3)(IMes)2] along with trans‐[Pt(F)(SOF)(IMes)2] and trans‐[Pt(F)(IMes’)(IMes)] (IMes’: cyclometalated IMes ligand), the latter being products produced by reaction with adventitious water. trans‐[Pt(F)(SOF)(IMes)2] and trans‐[Pt(F)2(IMes)2] were synthesized independently by treatment of [Pt(IMes)2] with SOF2 or XeF2. A reaction of [Pt(IMes)2] with a HF source gave trans‐[Pt(H)(F)(IMes)2], and an intermediate bifluorido complex trans‐[Pt(H)(FHF)(IMes)2] was identified. Compound trans‐[Pt(H)(F)(IMes)2] converts in the presence of CsF into trans‐[Pt(F)(IMes’)(IMes)].

Platinum Indolylphosphine Fluorido and Polyfluorido Complexes: An Interplay between Cyclometallation, Fluoride Migration, and Hydrogen Bonding.

The reaction of [PtCl2(COD)] (COD=1,5‐cyclooctadiene) with diisopropyl‐2‐(3‐methyl)indolylphosphine (iPr2P(C9H8N)) led to the formation of the platinum(ii) chlorido complexes, cis‐[PtCl2{iPr2P(C9H8N)}2] (1) and trans‐[PtCl2{iPr2P(C9H8N)}2] (2). The cis‐complex 1 reacted with NEt3 yielding the complex cis‐[PtCl{κ 2‐(P,N)‐iPr2 P(C9H7 N)}{iPr2P(C9H8N)}] (3) bearing a cyclometalated κ 2‐(P,N)‐phosphine ligand, while the isomer 2 with a trans‐configuration did not show any reactivity towards NEt3. Treatment of 1 or 3 with (CH3)4NF (TMAF) resulted in the formation of the twofold cyclometalated complex cis‐[Pt{κ 2‐(P,N)‐iPr2 P(C9H7 N)}2] (4). The molecular structures of the complexes 1–4 were determined by single‐crystal X‐ray diffraction. The fluorido complex cis‐[PtF{κ 2‐(P,N)‐iPr2 P(C9H7 N)}{iPr2P(C9H8N)}] ⋅ (HF)4 (5 ⋅ (HF)4) was formed when complex 4 was treated with different hydrogen fluoride sources. The Pt(ii) fluorido complex 5 ⋅ (HF)4 exhibits intramolecular hydrogen bonding in its outer coordination sphere between the fluorido ligand and the NH group of the 3‐methylindolyl moiety. In contrast to its chlorido analogue 3, complex 5 ⋅ (HF)4 reacted with CO or the ynamide 1‐(2‐phenylethynyl)‐2‐pyrrolidinone to yield the complexes trans‐[Pt(CO){κ 2‐(P,C)‐iPr2 P(C9H7NCO)}{iPr2P(C9H8N)}][F(HF)4] (7) and a complex, which we suggest to be cis‐[Pt{C=C(Ph)OCN(C3H6)}{κ 2‐(P,N)‐iPr2 P(C9H7 N)}{iPr2P(C9H8N)}][F(HF)4] (9), respectively. The structure of 9 was assigned on the basis of DFT calculations as well as NMR and IR data. Hydrogen bonding of HF and NH to fluoride was proven to be crucial for the existence of 7 and 9.

Versatile Reaction Pathways of 1,1,3,3,3-Pentafluoropropene at Rh(I) Complexes [Rh(E)(PEt3 )3 ] (E=H, GePh3 , Si(OEt)3 , F, Cl): C-F versus C-H Bond Activation Steps.

The reaction of the rhodium(I) complexes [Rh(E)(PEt3)3] (E=GePh3 (1), H (6), F (7)) with 1,1,3,3,3‐pentafluoropropene afforded the defluorinative germylation products Z/E‐2‐(triphenylgermyl)‐1,3,3,3‐tetrafluoropropene and the fluorido complex [Rh(F)(CF3CHCF2)(PEt3)2] (2) together with the fluorophosphorane E‐(CF3)CH=CF(PFEt3). For [Rh(Si(OEt)3)(PEt3)3] (4) the coordination of the fluoroolefin was found to give [Rh{Si(OEt)3}(CF3CHCF2)(PEt3)2] (5). Two equivalents of complex 2 reacted further by C−F bond oxidative addition to yield [Rh(CF=CHCF3)(PEt3)2(μ‐F)3Rh(CF3CHCF2)(PEt3)] (9). The role of the fluorido ligand on the reactivity of complex 2 was assessed by comparison with the analogous chlorido complex. The use of complexes 1, 4 and 6 as catalysts for the derivatization of 1,1,3,3,3‐pentafluoropropene provided products, which were generated by hydrodefluorination, hydrometallation and germylation reactions.

Studies on the reactivity of Rh(I) complexes towards SF5Cl

Sulfur chloride pentafluoride reacts with the rhodium(I) NHC complexes (N-heterocyclic carbene) trans-[Rh(Cl)(CO)(IMes)2] (1) and trans-[Rh(F)(CO)(IMes)2] (5) to give the cationic square-pyramidal complexes trans,trans-[Rh(Cl)2(CO)(IMes)2][SF5] (2) and trans-[Rh(Cl)(F)(CO)(IMes)2][SF5] (6) at 183 K. The compounds convert into the fluorido complexes trans,trans-[Rh(Cl)2(F)(CO)(IMes)2] (4) and cis,trans-[Rh(Cl)(F)2(CO)(IMes)2] (7) at ambient temperatures. In the reaction of 1 the rhodium(III) fluoroacyl complex trans,trans-[Rh(Cl)2(COF)(IMes)2] (3) was identified as additional product. DFT calculations were carried out in order to determine the configurations of the complexes 2, 3 and 6. For comparison the phosphine complex, trans-[Rh(F)(CO)(PEt3)2] (8) was treated with SF5Cl to yield cis,trans-[Rh(F)2(Cl)(CO)(PEt3)2] (9) at 183 K. At 213 K the sulfanyl complex cis,trans-[Rh(F)2(SF3)(CO)(PEt3)2] (10) was also identified.

Luminescent halido(aryl) Pt(IV) complexes obtained via oxidative addition of iodobenzene or diaryliodonium salts to bis-cyclometalated Pt(II) precursors.

The synthesis of bis-cyclometalated halido(aryl) Pt(IV) complexes [PtX(Ar)(C^N)2], with C^N = cyclometalated 4-(tert-butyl)-2-phenylpyridine (bppy), 2-(p-tolyl)pyridine (tpy), 2-(2-thienyl)pyridine (thpy), or 1-phenylisoquinoline (piq), X = I, Cl, or F, and Ar = Ph (for all C^N ligands) or t-BuPh (for C^N = tpy), and the photophysical properties of the chlorido and fluorido series is reported. The oxidative addition of iodobenzene to cis-[Pt(C^N)2] precursors is demonstrated to occur in MeCN under irradiation with visible light to give complexes [PtI(Ph)(C^N)2], presumably involving radical species that also produce the activation of the solvent to give cyanomethyl complexes [PtI(CH2CN)(C^N)2]. The introduction of an aryl ligand can also be achieved by reacting cis-[Pt(C^N)2] with (Ar2I)PF6 (Ar = Ph, t-BuPh), which affords cationic intermediates of the type [Pt(Ar)(C^N)2(NCMe)]+. The subsequent addition of an iodide or chloride salt gives the corresponding iodido- or chlorido(aryl) complexes. The fluorido(aryl) derivatives can be obtained from the iodido complexes by halide exchange using AgF. The chlorido- and fluorido(aryl) complexes display intense phosphorescence in deaerated CH2Cl2 solution and poly(methyl methacrylate) (PMMA) films at 298 K from triplet excited states primarily localized on the cyclometalated ligands (3LC) with a small MLCT admixture. Compared with the chlorido complexes, the fluorido derivatives consistently present significantly shorter emission lifetimes and higher radiative and nonradiative rate constants due to a greater MLCT contribution to the emissive state. In contrast, the introduction of the t-BuPh group did not induce significant changes in radiative rates with respect to the phenyl complexes.

Synthesis and Reactivity of Iridium(I) Fluorido Complexes: Oxidative Addition of SF4 at trans‐[Ir(F)(CO)(PEt3)2

The facile access to the Vaska type fluorido complexes trans‐[Ir(F)(CO)(PR3)2] [6: R = Et, 7: R = Ph, 8: R = iPr, 9: R = Cy, 10: R = tBu] was achieved by halide exchange at trans‐[Ir(Cl)(CO)(PR3)2] (1–5) with Me4NF. Furthermore, the reaction of complex 6 with SF4 gave cis,trans‐[Ir(F)2(SF3)(CO)(PEt3)2] (11), whereas 8–10 did not react. Reactivity studies revealed that 11 can selectively be manipulated at the sulfur atom by hydrolysis or fluoride abstraction to give cis,trans‐[Ir(F)2(SOF)(CO)(PEt3)2] (12) and cis,trans‐[Ir(F)2(SF2)(CO)(PEt3)2][AsF6] (13), respectively.

Activation of tetrafluoropropenes by rhodium(i) germyl and silyl complexes.

The reaction of the rhodium(i) complexes [Rh(E)(PEt3)3] (E = GePh3 (1), Si(OEt)3 (5)) with HFO-1234yf (2,3,3,3-tetrafluoropropene) afforded [Rh(F)(PEt3)3] (2) and the functionalized olefins Z-CF3CH[double bond, length as m-dash]CH(E) (E = GePh3 (4a), Si(OEt)3 (7)). Conceivable reaction pathways were assessed using DFT calculations. Reactions of [Rh(E)(PEt3)3] with HFO-1234ze (E-1,3,3,3-tetrafluoropropene) yielded the rhodium fluorido complex 2 and [Rh{(E)-CH[double bond, length as m-dash]CH(CF3)}(PEt3)3] (9) via two different reaction pathways. Using complexes 1 and 5 as catalysts, functionalized building blocks were obtained.

Selective Formation and Characterization of a RhIII Difluorido λ4‐Trifluorosulfanyl Complex

A general route to access the Vaska type fluorido complexes trans‐[Rh(F)(CO)(PR3)2] [R = Et (6), Ph (7), iPr (8), Cy (9), tBu (10)] was developed by treatment of trans‐[Rh(Cl)(CO)(PR3)2] (1–5) with Me4NF. The molecular structures of 8 and 9 were determined by X‐ray crystallography. Treatment of the complex 6 with SF4 resulted in the selective formation of complex cis,trans‐[Rh(F)2(SF3)(CO)(PEt3)2] (11), whereas the other fluoride complexes didn't react.