Tieftemperatur-flüssigphasefluorierung von pentafluorphenyl-element-Verbindungen. Darstellungen und eigenschaften von (C6F5)3AsF2, (C6F5)3SbF2, (C6F5)2SeF2, (C6F5)2SeO,C6F5TeF3 und Cs[(C6F5)3EF3] (E = As,Sb) [1]

The fluorination reactions of (C₆F₅)₃E (E = As, Sb) with elemental flourine yield (C₆F₅)₃EF₂ in high yields. From the reactions of (C₆F₅)₃EF₂ with CsF the new salts Cs[(C₆F₅)₃EF₃] are obtained. (C₆F₅)₂SeF₂ and C₆F₅TeF₃ are formed for the first time by reacting (C₆F₅)₂SeF and (C₆F₅)₂TeF₂ with elemental flourine and XeF₂, respectively. (C₆F₅)₂SeF₂ rapidly reacts with glass, and the new compound (C₆F₅)₂SeO is isolated. The preparations, properties and ¹⁹F NMR spectra of the new compounds are described.     

Infrared investigations of the order–disorder ferroelectric phase transitions in imidazolium halogenobismuthates(III) and halogenoantimonates(III): (C3N2H5)5Bi2Cl11, (C3N2H5)5Bi2Br11 and (C3N2H5)5Sb2Br11

Infrared spectra of the powdered (C₃N₂H₅)₅Bi₂Cl₁₁, (C₃N₂H₅)₅Bi₂Br₁₁and (C₃N₂H₅)₅Sb₂Br₁₁ crystals in the region of internal vibrations of the imidazolium cations (3600 and 400 cm⁻¹) at the temperature intervals of 10–300 K, covering paraelectric–ferroelectric phase transitions, are presented and discussed in this paper. The research shows that the vibrational states of the imidazolium cations change markedly during the paraelectric–ferroelectric phase transition. The continuous nature of these transitions is well reflected in the infrared spectra, which is consistent with the previous X-ray and dielectric findings.     

Luminescence properties of complexes Ln(Phen)(C6F5COO)3 (Ln = Tb, Eu) and Ln(C6F5COO)3 · nH2O (Ln = Tb, n = 2; Ln = Eu, n = 1). Structures of the [Tb2(H2O)8(C6F5COO)6] complex and its isomer in the supramolecular compound [Tb2(H2O)8(C6F5COO)6] · 2C6F5COOH

Complexes Ln(Phen)(C₆F₅COO)₃ (Ln = Tb, Eu; Phen = 1,10-phenanthroline) (I, II) are synthesized. At 300 K these complexes and compounds Ln(C₆F₅COO)₃ · nH₂O (Ln = Tb, n = 2; Ln = Eu, n = 1) (III, VI) possess photoluminescence (bright in the case of I and II). In the spectrum of compound I the line at 545 nm (transition ⁵ D ₄ → ⁷ F ₅) is most intense, whereas in the spectrum of compound II the most intense is the line at 613 nm (transition ⁵ D ₀ → ⁷ F ₂). The replacement of Phen by water decreases the luminescence intensity. The compound [Tb₂(H₂O)₈(C₆F₅COO)₆] · 2C₆F₅COOH (IV) is synthesized. According to the X-ray diffraction data, in structure IV the molecules of the binuclear Tb(III) complex with the C₆F₅COOH molecules form a supramolecular ensemble due to hydrogen bonding. The C₆F₅COO^? ligands perform the monodentate and bidentate bridging function, resulting in the opening of the eight-membered cycle Tb₂C₂O₄. The TbO₈ polyhedron is a distored tetragonal antiprism. The crystals of the binuclear complex [Tb₂(H₂O)₈(C₆F₅COO)₆] (V) are obtained in which the C₆F₅COO^? ligands are monodentate and tridentate bridging cyclic, which results in the closure of two four-membered cycles TbO₂C and one four-membered cycle Tb₂O₂. The TbO₉ polyhedron is a distorted monocapped tetragonal antiprism.     

Antimony(III) Oxofluorides α-Sb3O2F5 and β-Sb3O2F5: Synthesis and Crystal Structures

The conditions for the synthesis of two polymorphous forms of antimony(III) oxofluoride Sb₃O₂F₅ from aqueous solutions are established. The crystal structure of a new polymorphous modification -Sb₃O₂F₅ is determined (monoclinic crystals with a = 6.9548(6) Å, b = 9.1043(7) Å, c = 20.336(2) Å, = 94.167(2)°, V = 1284.2(2) ų, Z = 8, (calcd) = 5.092 g/cm³, F(000) = 1712, space group P2₁/n) and the structure of -Sb₃O₂F₅ is refined. The geometric characteristics of crystal structures of antimony(III) oxofluorides SbOF (L- and -forms) are compared with those of Sb₃O₂F₅ (- and -forms).     

Borane-induced dehydration of silica and the ensuing water-catalyzed grafting of B(C6F5)3 to give a supported, single-site Lewis acid, ≡SiOB(C6F5)2

A supported, single-site Lewis acid, ≡SiOB(C(6)F(5))(2), was prepared by water-catalyzed grafting of B(C(6)F(5))(3) onto the surface of amorphous silica, and its subsequent use as a cocatalyst for heterogeneous olefin polymerization was explored. Although B(C(6)F(5))(3) has been reported to be unreactive toward silica in the absence of a Br?nsted base, we find that it can be grafted even at room temperature, albeit slowly. The mechanism was investigated by (1)H and (19)F NMR, in both the solution and solid states. In the presence of a trace amount of H(2)O, either added intentionally or formed in situ by borane-induced dehydration of silanol pairs, the adduct (C(6)F(5))(3)B·OH(2) hydrolyzes to afford C(6)F(5)H and (C(6)F(5))(2)BOH. The latter reacts with the surface hydroxyl groups of silica to yield ≡SiOB(C(6)F(5))(2) sites and regenerate H(2)O. When B(C(6)F(5))(3) is present in excess, the resulting grafted boranes appear to be completely dry, due to the eventual formation of [(C(6)F(5))(2)B](2)O. The immobilized, tri-coordinate Lewis acid sites were characterized by solid-state (11)B and (19)F NMR, IR, elemental analysis, and C(5)H(5)N-TPD. Their ability to activate two molecular C(2)H(4) polymerization catalysts, Cp(2)ZrMe(2) and an (α-iminocarboxamidato)nickel(II) complex, was explored.     

Tris(pentafluoroethyl)silanol Derivatives and the Lewis Amphoteric Tris(pentafluoroethyl)silanolate Anion, [Si(C2F5)3O]−

While alkyl-substituted siloxanes are widely known, virtually nothing is known about perfluoroalkyl siloxanes and their congener species, the silanols and silanolates. We recently reported on the tris(pentafluoroethyl)silanide ion, [Si(C₂F₅)₃]⁻, which features Lewis amphoteric character deriving from the pentafluoroethyl substituents and their strong electron-withdrawing properties. Transferring this knowledge, we investigated the Lewis amphoteric behavior of the tris(pentafluoroethyl)silanolate, [Si(C₂F₅)₃O]⁻. In order to examine such Lewis amphoteric behavior, we first developed a strategy for the synthesis of the corresponding silanol Si(C₂F₅)₃OH, which readily condenses at room temperature to the hexakis(pentafluoroethyl)disiloxane, (C₂F₅)₃SiOSi(C₂F₅)₃. Deprotonation of Si(C₂F₅)₃OH employing a sterically demanding phosphazene base allows the characterization of the first example of a dimeric triorganosilanolate: the dianionic hexakis(pentafluoroethyl)disilanolate, [{Si(C₂F₅)₃O}₂]²⁻, implies Lewis amphoteric character of the monomeric [Si(C₂F₅)₃O]⁻ anion.     

Aurated tungsten-triosmium cluster compounds. Synthesis and characterization ofLWOs3(CO)12(AuPPh3) and related hydrogenation productsLWOs3(CO)11(μ-H)2(AuPPh3),L = C5 H5 and C5 Me5

Two heterometallic compoundsLWOs₃(CO)₁₂(AuPPh₃),L = Cp (6);L = Cp* (7), were prepared byin-situ generation of clusters [LWOs₃(CO)₁₂][PPh₄] from Os₃(CO)₁₀(NCMe)₂ and [LW(CO)₃][PPh₄], followed by addition of Ph₃ PAuCl. These derivatives possess a tetrahedral Os₃W core in which the AuPPh₃ unit bridges an Os-Os edge and the unique bridging CO ligand spans the opposite Os-W edge. Crystal data for6: space group P;a = 9.328(3),b = 13.745(3),c = 16.231(3) Á, = 115.00(2), = 97.27(2), = 90.17(2)°,Z = 2; finalR _F = 0 045,R _W = 0.044 for 4049 reflections withI > 2(I). Crystal data for7: space group P2₁/n;a = 9.775(2),b = 17.106(4),c = 25.074(3) Á, = 91.10(1)°,Z = 4; finalR _F = 0 035,R _W = 0.028 for 4196 reflections with I > 2(I). Hydrogenation of6 and7 afforded the respective dihydride complexesLWOs₃(CO)₁₁(-H)₂(AuPPh₃), (8)L = Cp; (9),L = Cp* in moderate yields. Their dynamic processes in solution were also established by¹H,¹³C and,³¹P NMR spectroscopies.     

β-Diketiminate Germylene-Supported Pentafluorophenylcopper(I) and -silver(I) Complexes [LGe(Me)(CuC(6)F(5))(n)](2) (n = 1, 2), LGe[C(SiMe(3))N(2)]AgC(6)F(5), and {LGe[C(SiMe(3))N(2)](AgC(6)F(5))(2)}(2) (L = HC[C(Me)N-2,6-iPr(2)C(6)H(3)](2)): Synthesis and Structural Characterization

Reactions of LGeMe (L = HC[C(Me)N-2,6-iPr(2)C(6)H(3)](2)) with 0.25 or 0.5 equiv of (CuC(6)F(5))(4) gave the products [LGe(Me)CuC(6)F(5)](2) (1) and [LGe(Me)(CuC(6)F(5))(2)](2) (2), respectively. In situ formed 1 reacted with 0.5 equiv of (CuC(6)F(5))(4) to give 2 on the basis of NMR ((1)H and (19)F) spectral measurements. Conversely, 2 was converted into 1 by treatment with 2 equiv of LGeMe. Reactions of LGeC(SiMe(3))N(2) with 1 or 2 equiv of AgC(6)F(5)·MeCN produced the corresponding compounds LGe[C(SiMe(3))N(2)]AgC(6)F(5) (3) and {LGe[C(SiMe(3))N(2)](AgC(6)F(5))(2)}(2) (4). Similarly, 3 was converted into 4 by treatment with 1 equiv of AgC(6)F(5)·MeCN and 4 converted into 3 by reaction with 2 equiv of LGeC(SiMe(3))N(2). X-ray crystallographic studies showed that 1 contains a rhombically bridged (CuC(6)F(5))(2), while 2 has a chain-structurally aggregated (CuC(6)F(5))(4), both supported by LGeMe. Correspondingly, 3 showed a terminally bound AgC(6)F(5) and 4 a chain-structurally aggregated (AgC(6)F(5))(4), both supported by LGeC(SiMe(3))N(2). Photophysical studies proved that the Ge-Cu metal-metalloid donor-acceptor bonding persists in solutions of 1 and 2 and Ge-Ag donor-acceptor bonding in solutions of 3 and 4 as a result of the clear migration of their emission bands compared to those of the corresponding starting materials. Low-temperature (-50 °C) (19)F NMR spectral measurements detected dissociation of 1, 2, and 4 by the aggregation part of the CuC(6)F(5) or AgC(6)F(5) entities in solution. These results provide good support for pentafluorophenylcopper(I) or -silver(I) species having β-diketiminate germylene as a donor because of its remarkably electronic and steric character.     

Tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)4]−, Ionic Liquids

We synthesized new imidazolium-based tunable aryl alkyl ionic liquids (TAAILs) with the weakly coordinating tetrakis(pentafluoroethyl)gallate anion, [Ga(C₂F₅)₄]⁻. Phenyl and phenyl derivatives (2-Me, 4-OMe, 2,4-F) were combined with varying alkyl chain lengths at the imidazolium core leading to TAAILs, which were investigated with regard to their viscosity, conductivity, and electrochemical window and compared to EMIM and BMIM standard cations. Remarkable low viscosities of 29 cP at 25 °C for [BMIM][Ga(C₂F₅)₄] were achieved. However, the EMIM and BMIM gallates show electrochemical instability, releasing pentafluoroethane at a voltage of 1.5 V. The 2-Me-substituted gallate-TAAILs slowly decompose over several weeks, whereas all other gallate-TAAILs showed no decomposition at all. With electrochemical windows of up to 5.15 V and low viscosities in a range of 66–162 cP, the gallate-TAAILs are promising candidates as electrolytes in electrochemical applications.     

Penta- and hexaphospha ferrocenes as ligands: crystal and molecular structures of [Fe(η5-P3C2tBu2)2W(CO)5], [Fe(η5-P3C2tBu2)(η5-P2C3tBu3)W(CO)5] and the novel triruthenium carbonyl cluster complex [Fe(η5-P3C2tBu2)2Ru3(CO)10] containing two interlinked η5-P3C2tBu2 ring systems

The lone-pair electrons of one of the two directly bonded phosphorus atoms of the P₃C₂^tBu₂ ring in the penta- or hexaphosphaferrocene complexes [Fe(η⁵-P₃C₂^tBu₂)(η⁵-P₃C₂^tBu₃)] and [Fe(η⁵P₃ C₂^tBu₂)₂] can ligate to other metal centres to afford novel bi- and tetrametallic complexes, whose structures have been elucidated by NMR and single crystal X-ray crystallographic studies.     

The Synthesis of the Arene Clusters Ru6C(CO)14(η6-Arene) (Arene = C6H5CHMe2, C6H5C4H9, C6H5C3H7, and C6H5C3H5)

On reaction with Ru₃(CO)₁₂, isopropenylbenzene and 4-phenyl-l-butene undergo hydrogenation, to yield the clusters, Ru₆C(CO)₁₄(⁶-C₆H₅CHMe₂) 1 and Ru₆C(CO)₁₄(⁶-C₆H₅C₄H₉) 2, respectively. With allylbenzene, both hydrogenation and isomerization occurs affording Ru₆C(CO)₁₄(⁶-C₆H₅C₃H₇) 3 and Ru₆C(CO)14(⁶-C₆H₅C₃H₅) 4. The structures of 1 and 2 have been established by single crystal X-ray diffraction. One of the Ru–Ru bond lengths in 2 is unusually long and extended Hückel molecular orbital calculations have been used in an attempt to rationalize this feature.     

Substitution and insertion reactions of (η5-C5H5)Cr(CO)3C2H5

The complex (η⁵-C₅H₅)Cr(CO)₃Cp42 H₅ has been made and its reactions with σ donor ligands L (L = (MeO)₃P and (EtO)₃P) and with SO₂ studied. The alkyl phosphites give compounds of the composition (η⁵-C₅H₅)Cr(CO)₂LC₂H₅, and sulfur dioxide gives the corresponding S-sulfinato (η⁵-C₅H₅)Cr(CO)₃SO₂C₂H₅.     

Synthesis and molecular structure of [1, 3-(Me3Si)2C5H3]2Lu(μ-Cl)2

Cp^* ₂Lu(-Cl)₂ (1) was isolated following the reaction of Cp^*Na (Cp^* = 1, 3-(Me₃Si)₂C₅H₃) with LuCl₃ in THF and subsequent treatment with toluene at 80°C. An X-ray structural investigation of1 was performed (MoK radiation, 2933 reflections,R = 0.020). The crystals are triclinic,a = 10.744(3) Å,b=11.821(2) Å, c=12.966(3) Å, a=71.54(1)°, =85.32(2)°, =74.83(1)°,Z = 2, space groupP-1. Two Lu atoms withdistorted tetrahedral coordination are linked by two chloride bridges with a mean Lu-Cl distance equal to 2.62 Å.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 568–570, March, 1993.     

Theoretical Exploration of Stereochemical Nonrigidity for RfCo（PF3）x（CO）4-x（Rf=CF3, C2F5, C3F7, x=0-4）

The stereochemical nonrigidity of RfCo（PF3）x（CO）4-x（Rf=CF3,C2F5,C3F7,x=0-4） was studied at the theoretical level of B3LYP/6-31 1＋G^＊ via Gaussian 09.The intramolecular rearrangements in these penta-coordinated compounds are mainly caused by the vibrations of perfluoroalkyl groups.All the barriers along the reaction coordinate are less than 66.9 kJ/mol,which indicates that the rearrangements are kinetically favorable and hard to elucidate by experiment.Besides,ligand PF3 is a ligand similar to CO,the energy difference between the reactant and product is small.     

Cluster synthesis 37—Platinum-ruthenium carbido-cluster complexes: The syntheses and structural characterizations of PtRu5(C)(CO)16, Pt2Ru5(C)(CO)13(COD)2, and Pt3Ru5(C)(CO)14(COD)2

From the reaction of [Ru₅(C)(CO)₁₄]^2– with Pt(COD)Cl₂, COD=1, 5 cyclooctadiene, the new platinum-ruthenium carbido cluster complex PtRu₅ (C)(CO)₁₄(COD),1, was obtained in 41% yield. When1 was allowed to react with carbon monoxide (25°C/1 atm), the new complex PtRu₅(C)(CO)₁₆,2, was obtained almost quantitatively (97% yield). Compound2 was characterized by IR and single-crystal X-ray diffraction analysis. The six metal atoms are arranged in the form of an octahedron with the carbide ligand located in the center. Compound1 is believed to have a similar structure to2 except for a COD ligand coordinated to the platinum atom. When activated by treatment with Me₃NO, compound2 reacts with Pt(COD)₂ at 25°C to yield two higher nuclearity cluster complexes, Pt₂Ru₅C(CO)₁₃(COD)₂.3, and Pt₃Ru₅C(CO)₁₄(COD)₂,4. The structure of3 is similar to that of1, but contains a Pt(COD) grouping capping one Ru₃ triangle of the PtRu₅ octahedron. The structure of4 consists of a PtRu₅ octahedron with two Pt(COD) capping groups, one on an Ru₃ triangle and the other on a PtRu₂ triangle of the octahedron. Crystal data: for2, space group=P2₁/n,a=9.341 (2) Å,b=14.957 (3) Å,c=36.80 (1) Å, =90.38 (2) °,Z=8, 4034 reflections,R=0.030, for3, space group=P2₁/c,a=14.998 (3) Å,b=10.288 (3) Å,c=26.581 (7) Å, =102.75 (2) °,Z=4, 2917 reflections,R=0.028. for4, space group=P2₁/n,a=13.412 (4) Å,b=16.252 (4) Å,c=20.107 (4) Å, =106.13 (2) °,Z=4, 2745 reflections,R=0.032.     

Synthesis and structures of the η5-C5H5Cl(CO)2W-η1,η5-(PPh2)C5H4(CO)2Fe-η1,η5-C5H4Mn(CO)3 and MeSi[C5H4(CO)2Fe-η1,η5-C5H4Mn(CO)2PPh3]3 complexes

The metallation of the η⁵-C₅H₅(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ complex with BuⁿLi (THF, ?78 °C) followed by the treatment of the lithium derivative with Ph₂PCl afforded the η⁵-Ph₂PC₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ complex. The reaction of the latter with η⁵-C₅H₅(CO)₃WCl in the presence of Me₃NO produced the trinuclear complex η⁵-C₅H₅Cl(CO)₂W-η¹,η⁵-(Ph₂P)C₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃. The structure of the latter complex was established by IR, UV, and 1H and ³¹P NMR spectroscopy and X-ray diffraction. The reaction of MeSiCl₃ with three equivalents of LiC₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₂PPh₃ gave the hexanuclear complex MeSi[C₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₂PPh₃]₃.     

Fluorine-Containing Furan-3(2Н)-Ones in Reactions with Binucleophiles: CF3vs C2F5

Chemistry of Heterocyclic Compounds - Five- and six-membered fluorine-containing azaheterocycles were synthesized based on available furan-3(2H)-ones, and the influence of the nature of the...     

2-Polyfluoroalkylchromones. 11. Synthesis and structures of 5-hydroxy-3-(2-hydroxyaryl)-5-polyfluoroalkyl-Δ2-pyrazolines and 3(5)-(2-hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles

The reaction of 2-hydroxy-2-polyfluoroalkylchroman-4-ones with hydrazine affords 5-hydroxy-3-(2-hydroxyaryl)-5-polyfluoroalkyl-²-pyrazolines, whereas 2-polyfluoroalkylchromones under similar conditions produce 3(5)-(2-hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles. 5-(2-Hydroxyaryl)-1-methyl-3-polyfluoroalkylpyrazoles were synthesized in the reaction with methylhydrazine, and the reaction with phenylhydrazine afforded regioisomeric 3(5)-(2-hydroxyphenyl)-1-phenyl-5(3)-polyfluoroalkylpyrazoles.     

The all non-metal homodinuclear and heterodinuclear sandwich-like compounds C2(η3-L3)2 and BN(η3-L3)2 (L = BCO, BNN and CBO)

Density functional theory studies on the all non-metal homodinuclear and heterodinuclear sandwich-like compounds C(2)(η(3)-L(3))(2) and BN(η(3)-L(3))(2) (L = BCO, BNN and CBO) have been performed. The staggered conformations of both C(2)(η(3)-L(3))(2) and BN(η(3)-L(3))(2) are predicted to be stable. The non-metal direct C-C and B-N bonds are covalent with σ interactions, which are formed by the interactions of s and p(z) orbitals of the center atoms. Different from the ionic metal-ligand bond in the traditional metal center sandwich-like compounds, the C-L, B-L, and N-L bonds are covalent in these all non-metal sandwich-like compounds. The NICS values indicate that the ligands of C(2)(η(3)-L(3))(2) and BN(η(3)-L(3))(2), as well as their bare rings, display multiple aromaticity (σ and π aromaticity). Both σ and π aromaticity of the ring ligands towards the center atoms become stronger after complexation with the center atoms, while the π aromaticity against the center atoms is reduced. The π aromaticity of the ligands bonded to different center atoms follows a trend of B > C > N, and the (CBO)(3)(+) ligands bonded to B possess the strongest π aromaticity. The dissociation reactions and possible synthetic reactions analysis show that these all non-metal sandwich-like compounds are stable, and the homodinuclear species are more stable than the heterodinuclear ones. These all non-metal binuclear sandwich-like compounds can be regarded as potential synthetic targets according to the highly negative free energies of the possible synthetic reactions. The isomerization reactions demonstrate that the CBO-based compounds should be more possible to synthesize in experiments than their BCO-based isomers.     

Synthesis, crystal structure, and optical properties of a novel rare-earth complex Nd(C2F5COO)3 · Phen

A novel neodymium pentafluoropropionate binuclear complex, Nd(C₂F₅COO)₃ · Phen (Phen: 1,10-phenanthroline), was synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, FT-IR spectra, UV–Vis–NIR absorption, and PL spectra. Single-crystal data show that the complex bears centrosymmetric dinuclear structure with a planar ligand configuration. Four carboxylato groups act as η²-chelate-μ²-carboxylato-k¹O:k¹O′-bridge-ligands, the other two occupy the terminal position as monodentate ligands. At the same time, the C–O distances appear averaged which indicate the three atoms of carboxylato forming electron-conjugate system. Hydrogen bond and π–π-stacking link the binuclear to two-dimensional sheet. Optical spectra exhibit the complex possesses typical Nd(III) ion absorption and photoluminescence emission.