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1.
NO[Al(OC(CF(3))(2)Ph)(4)] 1 and NO[Al(OC(CF(3))(3))(4)] 2 were obtained by the metathesis reaction of NO[SbF(6)] and the corresponding Li[Al(OR)(4)] salts in liquid sulfur dioxide solution in ca 40% (1) and 85% (2) isolated yield. 1 and 2, as well as Li[NO(3)] and N(2)O, were also given by the reaction of an excess of mixture of (90 mol%) NO, (10 mol%) NO(2) with Li[Al(OR)(4)] followed by extraction with SO(2). The unfavourable disproportionation reaction of 2NO(2)(g) to [NO](+)(g) and [NO(3)](-)(g)[DeltaH degrees = +616.2 kJ mol(-1)] is more than compensated by the disproportionation energy of 3NO(g) to N(2)O(g) and NO(2)(g)[DeltaH degrees =-155.4 kJ mol(-1)] and the lattice energy of Li[NO(3)](s)[U(POT)= 862 kJ mol(-1)]. Evidence is presented that the reaction proceeds via a complex of [Li](+) with NO, NO(2)(or their dimers) and N(2)O. NO(2) and Li[Al(OC(CF(3))(3))(4)] gave [NO(3)(NO)(3)][Al(OC(CF(3))(3))(4)](2), NO[Al(OC(CF(3))(3))(4)] and (NO(2))[Al(OC(CF(3))(3))(4)] products. The aluminium complex [Li[AlF(OC(CF(3))(2)Ph)(3)]](2) 3 was prepared by the thermal decomposition of Li[Al(OC(CF(3))(2)Ph)(4)]. Compounds 1 and 3 were characterized by single crystal X-ray structural analyses, 1-3 by elemental analyses, NMR, IR, Raman and mass spectra. Solid 1 contains [Al(OC(CF(3))(2)Ph)(4)](-) and [NO](+) weakly linked via donor acceptor interactions, while in the SO(2) solution there is an equilibrium between the associated [NO](+)[Al(OC(CF(3))(2)Ph)(4)](-) and separated solvated ions. Solid 2 contains essentially ionic [NO](+) and [Al(OC(CF(3))(3))(4)](-). Complex 3 consists of two [Li[AlF(OC(CF(3))(2)Ph)(3)]] units linked via fluorine lithium contacts. Compound 1 is unstable in the SO(2) solution and decomposes to yield [AlF(OC(CF(3))(2)Ph)(3)](-), [(PhC(CF(3))(2)O)(3)Al(mu-F)Al(OC(CF(3))(2)Ph)(3)](-) anions as well as (NO)C(6)H(4)C(CF(3))(2)OH, while compound 2 is stable in liquid SO(2). The [small nu](NO(+)) in 1 and [NO](+)(toluene)[SbCl(6)] are similar, implying similar basicities of [Al(OC(CF(3))(2)Ph)(4)](-) and toluene.  相似文献   

2.
The title compound [2,6-Mes(2)C(2)H(3)](2)Ga(+)Li[Al(OCH(CF(3))(2))(4)](2)(-), 1, containing a linear two-coordinate gallium cation, has been obtained by metathesis reaction of [2,6-Mes(2)C(2)H(3)](2)GaCl with 2 equiv of Li[Al(OCH(CF(3))(2))(4)] in C(6)H(5)Cl solution at room temperature. Compound 1 has been characterized by (1)H, (13)C((1)H), (19)F, and (27)Al NMR spectroscopy and X-ray crystallography. Compound 1 consists of isolated [2,6-Mes(2)C(6)H(3)](2)Ga(+) cations and Li[Al(OCH(CF(3))(2))(4)](2)(-) anions. The C-Ga-C angle is 175.69(7) degrees, and the Ga-C distances are 1.9130(14) and 1.9145(16) A. The title compound is remarkably stable, is only a weak Lewis acid, and polymerizes cyclohexene oxide.  相似文献   

3.
The CX3(+) salts [CCl(3)](+)[Al(OR(F))(4)](-)1, [CCl(3)](+)[(R(F)O)(3)Al-F-Al(OR(F))(3)](-)2, [CBr(3)](+)[Al(OR(F))(4)](-)3, [CBr(3)](+)[(R(F)O)(3)Al-F-Al(OR(F))(3)](-)4 (R(F) = C(CF(3))(3)) were prepared in 56 to 85% yield from CX(4) (X = Cl, Br) and the corresponding silver salts (weight balance, NMR, IR, X-ray structure of 1). The most convenient solvent for the preparation of 1 and 2 is SO(2)ClF but for 3 and 4 it is SO(2). The reactions are complete after about three days stirring at -30 to -40 °C. The salts are stable for weeks in solution at -40 °C and stable for a few hours at RT in the solid state. In SO(2)ClF (1, 2) or SO(2) (3, 4) solution they decompose slowly at -20 °C and within several hours at RT; in general the CBr3(+) salts are more stable than the CCl3(+) homologues. The decomposition products were assigned as CCl(3)F and primarily CBr(2)F(2) (which likely forms as a Lewis acid induced disproportionation product of the initial CBr(3)F). The C-X vibrations of the salts were found in the expected range and the assignments were made based on experimental and calculated data. The IR spectrum of a CBr3(+) salt is for the first time reported here.  相似文献   

4.
Short-lived (CF(3))(3)B and (CF(3))(3)BCF(2) are generated as intermediates by thermal dissociation of (CF(3))(3)BCO and F(-) abstraction from the weak coordinating anion [B(CF(3))(4)](-), respectively. Both Lewis acids cannot be detected because of their instability with respect to rearrangement reactions at the B-C-F moiety. A cascade of 1,2-fluorine shifts to boron followed by perfluoroalkyl group migrations and also difluorocarbene transfer reactions occur. In the gas phase, (CF(3))(3)B rearranges to a mixture of linear perfluoroalkyldifluoroboranes C(n)()F(2)(n)()(+1)BF(2) (n = 2-7), while the respective reactions of (CF(3))(3)BCF(2) result in a mixture of linear (n = 2-4) and branched monoperfluoroalkyldifluoroboranes, e.g., (C(2)F(5))(CF(3))FCBF(2). For comparison, the reactions of [CF(3)BF(3)](-) and [C(2)F(5)BF(3)](-) with AsF(5) are studied, and the products in the case of [CF(3)BF(3)](-) are BF(3) and C(2)F(5)BF(2) whereas in the case of [C(2)F(5)BF(3)](-), C(2)F(5)BF(2) is the sole product. In contrast to reports in the literature, it is found that CF(3)BF(2) is too unstable at room temperature to be detected. The decomposition of (CF(3))(3)BCO in anhydrous HF leads to a mixture of the new conjugate Br?nsted-Lewis acids [H(2)F][(CF(3))(3)BF] and [H(2)F][C(2)F(5)BF(3)]. All reactions are modeled by density functional calculations. The energy barriers of the transition states are low in agreement with the experimental results that (CF(3))(3)B and (CF(3))(3)BCF(2) are short-lived intermediates. Since CF(2) complexes are key intermediates in the rearrangement reactions of (CF(3))(3)B and (CF(3))(3)BCF(2), CF(2) affinities of some perfluoroalkylfluoroboranes are presented. CF(2) affinities are compared to CO and F(-) affinities of selected boranes showing a trend in Lewis acidity, and its influence on the stability of the complexes is discussed. Fluoride ion affinities are calculated for a variety of different fluoroboranes, including perfluorocarboranes, and compared to those of the title compounds.  相似文献   

5.
The stabilization of the P(CF(3))(2)(-) ion by intermediary coordination to the very weak Lewis acid acetone gives access to single crystals of [18-crown-6-K]P(CF(3))(2). The X-ray single crystal analysis exhibits nearly isolated P(CF(3))(2)(-) ions with an unusually short P-C distance of 184(1) pm, which can be explained by negative hyperconjugation and is also found by quantum chemical hybrid DFT calculation. Coordination of the P(CF(3))(2)(-) ion to pentacarbonyl tungsten has only a minor effect on electronic and geometric properties of the P(CF(3))(2) moiety, while a strong increase in thermal stability of the dissolved species is achieved. The hitherto unknown P(C(6)F(5))(2)(-) ion is stabilized by coordination to pentacarbonyl tungsten and isolated as a stable 18-crown-6 potassium salt, [18-crown-6-K][W[P(C(6)F(5))(2)](CO)(5)], which is fully characterized. The tungstate, [W[P(C(6)F(5))(2)](CO)(5)](-), decomposes slowly in solution, while coordination of the phosphorus atom to a second pentacarbonyl tungsten moiety results in an enhanced thermal stability in solution. The single-crystal X-ray analysis of [18-crown-6-K][[W(CO)(5)](2)[mu-P(C(6)F(5))(2)]].THF exhibits a very tight arrangement of the two C(6)F(5) and two W(CO)(5) groups around the central phosphorus atom. NMR spectroscopic investigations of the [[W(CO)(5)](2)[mu-P(C(6)F(5))(2)]](-) ion exhibit a hindered rotation of both the C(6)F(5) and W(CO)(5) groups in solution.  相似文献   

6.
While reinvestigating the published synthesis of OPI(3), it became evident from the experiments that phosphoryl triodide may only be formed as an intermediate and that the end products of the reaction of OPCl(3) with LiI are P(V) oxides, PI(3), I(2), and LiCl. This is also in agreement with MP2/TZVPP calculations, which assign Delta(r)H degrees (Delta(r)G degrees ) [Delta(r)G degrees in CHCl(3)] for the disproportionation of OPI(3) as -7 (-18) [-17 kJ mol(-1)] (assuming P(4)O(10) as the P(V) oxide). The first products of this reaction visible in a low-temperature in situ (31)P NMR experiment are P(2)I(4) and PI(3), as well as traces of a compound that may be OPCl(2)I. By contrast, it was possible to prepare and structurally characterize Lewis acid [A] stabilized [A]<--OPX(3) adducts, where [A] is Al(OR(F))(3) for X=Br and Al(OR(F))(2)(mu-F)Al(OR(F))(3) for X=I (R(F)=C(CF(3))(3)). These adducts are formed on decomposition of PX(4) (+)[Al(OR(F))(4)](-); high yields of Br(3)PO-->Al(OR(F))(3) (delta((31)P)=-65) were obtained, while I(3)PO-->Al(OR(F))(3) (delta((31)P)=-337) and I(3)PO-->Al(OR(F))(2)(mu-F)Al(OR(F))(3) (delta((31)P)=-332) are only formed as by-products. The main product of the room-temperature decomposition of PI(4) (+)[Al(OR(F))(4)](-) is PI(4) (+)[(R(F)O)(3)Al(mu-F)Al(OR(F))(3)](-), which was also characterized by X-ray crystallography and was independently prepared from Ag(+)[(R(F)O)(3)Al(mu-F)Al(OR(F))(3)](-), PI(3), and I(2).  相似文献   

7.
The thermally unstable compound [Hg[P(C(6)F(5))(2)](2)] was obtained from the reaction of mercury cyanide and bis(pentafluorophenyl)phosphane in DMF solution and characterized by multinuclear NMR spectroscopy. The thermally stable trinuclear compounds [Hg[(mu-P(CF(3))(2))W(CO)(5)](2)] and [Hg[(mu-P(C(6)F(5))(2))W(CO)(5)](2)] are isolated and completely characterized. The higher order NMR spectra exhibiting multinuclear satellite systems have been sufficiently analyzed. [Hg[(mu-P(CF(3))(2))W(CO)(5)](2)].2DMF crystallizes in the monoclinic space group C2/c with a = 2366.2(3) pm, b = 1046.9(1) pm, c = 104.0(1) pm, and beta = 104.01(1) degrees. Structural, NMR spectroscopic, and vibrational data prove a weak coordination of the two DMF molecules. Structural, vibrational, and NMR spectroscopic evidence is given for a successive weakening of the pi back-bonding effect of the W-P bond in the order [W(CO)(5)PH(R(f))(2)], [Hg[(mu-P(R(f))(2))W(CO)(5)](2)], and [W[P(R(f))(2)](CO)(5)](-) with R(f) = C(6)F(5) and CF(3). The pi back-bonding effect of the W-C bonds increases vice versa.  相似文献   

8.
The first example of a mononuclear diphosphanidoargentate, bis[bis(trifluoromethyl)phosphanido]argentate, [Ag[P(CF(3))(2)](2)](-), is obtained via the reaction of HP(CF(3))(2) with [Ag(CN)(2)](-) and isolated as its [K(18-crown-6)] salt. When the cyclic phosphane (PCF(3))(4) is reacted with a slight excess of [K(18-crown-6)][Ag[P(CF(3))(2)](2)], selective insertion of one PCF(3) unit into each silver phosphorus bond is observed, which on the basis of NMR spectroscopic evidence suggests the [Ag[P(CF(3))P(CF(3))(2)](2)](-) ion. On treatment of the phosphane complexes [M(CO)(5)PH(CF(3))(2)] (M = Cr, W) with [K(18-crown-6)][Ag(CN)(2)], the analogous trinuclear argentates, [Ag[(micro-P(CF(3))(2))M(CO)(5)](2)](-), are formed. The chromium compound [K(18-crown-6)][Ag[(micro-P(CF(3))(2))Cr(CO)(5)](2)] crystallizes in a noncentrosymmetric space group Fdd2 (No. 43), a = 2970.2(6) pm, b = 1584.5(3) pm, c = 1787.0(4), V = 8.410(3) nm(3), Z = 8. The C(2) symmetric anion, [Ag[(micro-P(CF(3))(2))Cr(CO)(5)](2)](-), shows a nearly linear arrangement of the P-Ag-P unit. Although the bis(pentafluorophenyl)phosphanido compound [Ag[P(C(6)F(5))(2)](2)](-) has not been obtained so far, the synthesis of its trinuclear counterpart, [K(18-crown-6)][Ag[(micro-P(C(6)F(5))(2))W(CO)(5)](2)], was successful.  相似文献   

9.
New catalysts for the isospecific polymerization of 1-hexene based on cationic zirconium complexes incorporating the tetradentate fluorous dialkoxy-diamino ligands [OC(CF(3))(2)CH(2)N(Me)(CH(2))(2)N(Me)CH(2)C(CF(3))(2)O](2-) [(ON(2)NO)(2-)] and [OC(CF(3))(2)CH(2)N(Me)(1R,2R-C(6)H(10))N(Me)CH(2)C(CF(3))(2)O](2-) [(ON(Cy)NO)(2-)] have been developed. The chiral fluorous diamino-diol [(ON(Cy)NO)H(2), 2] was prepared by ring-opening of the fluorinated oxirane (CF(3))(2)COCH(2) with (R,R)-N,N'-dimethyl-1,2-cyclohexanediamine. Proligand 2 reacts cleanly with [Zr(CH(2)Ph)(4)] and [Ti(OiPr)(4)] precursors to give the corresponding dialkoxy complexes [Zr(CH(2)Ph)(2)(ON(Cy)NO)] (3) and [Ti(OiPr)(2)(ON(Cy)NO)] (4), respectively. An X-ray diffraction study revealed that 3 crystallizes as a 1:1 mixture of two diastereomers (Lambda-3 and Delta-3), both of which adopt a distorted octahedral structure with trans-O, cis-N, and cis-CH(2)Ph ligands. The two diastereomers Lambda-3 and Delta-3 adopt a C(2)-symmetric structure in toluene solution, as established by NMR spectroscopy. Cationic complexes [Zr(CH(2)Ph)(ON(2)NO)(THF)(n)](+) (n=0, anion=[B(C(6)F(5))(4)](-), 5; n=1, anion=[PhCH(2)B(C(6)F(5))(3)](-), 6) and [Zr(CH(2)Ph)(ON(Cy)NO)(THF)](+)[PhCH(2)B(C(6)F(5))(3)](-) (7) were generated from the neutral parent precursors [Zr(CH(2)Ph)(2)(ON(2)NO)] (H) and [Zr(CH(2)Ph)(2)(ON(Cy)NO)] (3), and their possible structures were determined on the basis of (1)H, (19)F, and (13)C NMR spectroscopy and DFT methods. The neutral zirconium complexes H and 3 (Lambda-3/Delta-3 mixture), when activated with B(C(6)F(5))(3) or [Ph(3)C](+)[B(C(6)F(5))(4)](-), catalyze the polymerization of 1-hexene with overall activities of up to 4500 kg PH mol Zr(-1) h(-1), to yield isotactic-enriched (up to 74 % mmmm) polymers with low-to-moderate molecular weights (M(w)=4800-47 200) and monodisperse molecular-weight distributions (M(w)/M(n)=1.17-1.79).  相似文献   

10.
Halide exchange from the species tBu(3)P(CO(2))B(C(6)F(5))(2)Cl 1 with Me(3)SiOSO(2)CF(3) gave tBu(3)P(CO(2))B(C(6)F(5))(2)(OSO(2)CF(3)) 2. Similarly, Lewis acid exchange occurs in reactions of 1 with Al(C(6)F(5))(3) and [Cp(2)TiMe][B(C(6)F(5))(4)] affording the products, tBu(3)P(CO(2))Al(C(6)F(5))(3)3 and [tBu(3)P(CO(2))TiCp(2)Cl][B(C(6)F(5))(4)] 4.  相似文献   

11.
In a new oxidative route, Ag(+)[Al(OR(F))(4)](-) (R(F)=C(CF(3))(3)) and metallic indium were sonicated in aromatic solvents, such as fluorobenzene (PhF), to give a precipitate of silver metal and highly soluble [In(PhF)(n)](+) salts (n=2, 3) with the weakly coordinating [Al(OR(F))(4)](-) anion in quantitative yield. The In(+) salt and the known analogous Ga(+)[Al(OR(F))(4)](-) were used to synthesize a series of homoleptic PR(3) phosphane complexes [M(PR(3))(n)](+), that is, the weakly PPh(3)-bridged [(Ph(3)P)(3)In-(PPh(3))-In(PPh(3))(3)](2+) that essentially contains two independent [In(PPh(3))(3)](+) cations or, with increasing bulk of the phosphane, the carbene-analogous [M(PtBu(3))(2)](+) (M=Ga, In) cations. The M(I)-P distances are 27 to 29 pm longer for indium, and thus considerably longer than the difference between their tabulated radii (18 pm). The structure, formation, and frontier orbitals of these complexes were investigated by calculations at the BP86/SV(P), B3LYP/def2-TZVPP, MP2/def2-TZVPP, and SCS-MP2/def2-TZVPP levels.  相似文献   

12.
The synthesis and characterization of a series of mononuclear d(8) complexes with at least two P-coordinated alkynylphosphine ligands and their reactivity toward cis-[Pt(C(6)F(5))(2)(THF)(2)] are reported. The cationic [Pt(C(6)F(5))(PPh(2)C triple-bond CPh)(3)](CF(3)SO(3)), 1, [M(COD)(PPh(2)C triple-bond CPh)(2)](ClO(4)) (M = Rh, 2, and Ir, 3), and neutral [Pt(o-C(6)H(4)E(2))(PPh(2)C triple-bond CPh)(2)] (E = O, 6, and S, 7) complexes have been prepared, and the crystal structures of 1, 2, and 7.CH(3)COCH(3) have been determined by X-ray crystallography. The course of the reactions of the mononuclear complexes 1-3, 6, and 7 with cis-[Pt(C(6)F(5))(2)(THF)(2)] is strongly influenced by the metal and the ligands. Thus, treatment of 1 with 1 equiv of cis-[Pt(C(6)F(5))(2)(THF)(2)] gives the double inserted cationic product [Pt(C(6)F(5))(S)mu-(C(Ph)=C(PPh(2))C(PPh(2))=C(Ph)(C(6)F(5)))Pt(C(6)F(5))(PPh(2)C triple-bond CPh)](CF(3)SO(3)) (S = THF, H(2)O), 8 (S = H(2)O, X-ray), which evolves in solution to the mononuclear complex [(C(6)F(5))(PPh(2)C triple-bond CPh)Pt(C(10)H(4)-1-C(6)F(5)-4-Ph-2,3-kappaPP'(PPh(2))(2))](CF(3) SO(3)), 9 (X-ray), containing a 1-pentafluorophenyl-2,3-bis(diphenylphosphine)-4-phenylnaphthalene ligand, formed by annulation of a phenyl group and loss of the Pt(C(6)F(5)) unit. However, analogous reactions using 2 or 3 as precursors afford mixtures of complexes, from which we have characterized by X-ray crystallography the alkynylphosphine oxide compound [(C(6)F(5))(2)Pt(mu-kappaO:eta(2)-PPh(2)(O)C triple-bond CPh)](2), 10, in the reaction with the iridium complex (3). Complexes 6 and 7, which contain additional potential bridging donor atoms (O, S), react with cis-[Pt(C(6)F(5))(2)(THF)(2)] in the appropriate molar ratio (1:1 or 1:2) to give homo- bi- or trinuclear [Pt(PPh(2)C triple-bond CPh)(mu-kappaE-o-C(6)H(4)E(2))(mu-kappaP:eta(2)-PPh(2)C triple-bond CPh)Pt(C(6)F(5))(2)] (E = O, 11, and S, 12) and [(Pt(mu(3)-kappa(2)EE'-o-C(6)H(4)E(2))(mu-kappaP:eta(2)-PPh(2)C triple-bond CPh)(2))(Pt(C(6)F(5))(2))(2)] (E = O, 13, and S, 14) complexes. The molecular structure of 14 has been confirmed by X-ray diffraction, and the cyclic voltammetric behavior of precursor complexes 6 and 7 and polymetallic derivatives 11-14 has been examined.  相似文献   

13.
We report herein the synthesis and full characterization of the donor‐free Lewis superacids Al(ORF)3 with ORF=OC(CF3)3 ( 1 ) and OC(C5F10)C6F5 ( 2 ), the stabilization of 1 as adducts with the very weak Lewis bases PhF, 1,2‐F2C6H4, and SO2, as well as the internal C? F activation pathway of 1 leading to Al2(F)(ORF)5 ( 4 ) and trimeric [FAl(ORF)2]3 ( 5 , ORF=OC(CF3)3). Insights have been gained from NMR studies, single‐crystal structure determinations, and DFT calculations. The usefulness of these Lewis acids for halide abstractions has been demonstrated by reactions with trityl chloride (NMR; crystal structures). The trityl salts allow the introduction of new, heteroleptic weakly coordinating [Cl‐Al(ORF)3]? anions, for example, by hydride or alkyl abstraction reactions.  相似文献   

14.
The recently reported homologous low-valent indium and gallium salts M(+)[Al(OR(F))(4)](-) (M = Ga, In; R(F) = C(CF(3))(3)) were used to extend the coordination chemistry of Ga(I) and In(I) to the isolated [18]crown-6 complexes [M([18]crown-6)(PhF)(2)](+)[Al(OR(F))(4)](-) in fluorobenzene solution (PhF = C(6)H(5)F). In contrast to known ion-paired compounds for M = In, our complexes are undisturbed and in the solid state free of contacts to the anion. A peculiar combination of very weak η(1)- and η(6)-coordination to the PhF-solvent was observed that allows speculation about the presence of a stereochemically active lone pair at M(I). Structure and energetics of these novel salts were rationalized on the basis of DFT calculations.  相似文献   

15.
The reactions of the hydroxo complexes [M(2)R(4)(mu-OH)(2)](2)(-) (M = Pd, R = C(6)F(5), C(6)Cl(5); M = Pt, R = C(6)F(5)), [[PdR(PPh(3))(mu-OH)](2)] (R = C(6)F(5), C(6)Cl(5)), and [[Pt(C(6)F(5))(2)](2)(mu-OH)(mu-pz)](2-) (pz = pyrazolate) with H(2)S yield the corresponding hydrosulfido complexes [M(2)(C(6)F(5))(4)(mu-SH)(2)](2-), [[PdR(PPh(3))(mu-SH)](2)], and [[Pt(C(6)F(5))(2)](2)(mu-SH)(mu-pz)](2-), respectively. The monomeric hydrosulfido complexes [M(C(6)F(5))(2)(SH)(PPh(3))](-) (M = Pd, Pt) have been prepared by reactions of the corresponding binuclear hydrosulfido complexes [M(2)(C(6)F(5))(4)(mu-SH)(2)](2-) with PPh(3) in the molar ratio 1:2, and they can be used as metalloligands toward Ag(PPh(3))(+) to form the heterodinuclear complex [(C(6)F(5))(2)(PPh(3))[S(H)AgPPh(3)]], and toward Au(PPh(3))(+) yielding the heterotrinuclear complexes [M(C(6)F(5))(2)(PPh(3))[S(AuPPh(3))(2)]]. The crystal structures of [NBu(4)](2)[[Pt(C(6)F(5))(2)(mu-SH)](2)], [Pt(C(6)F(5))(2)(PPh(3))[S(H)AgPPh(3)]], and [Pt(C(6)F(5))(2)(PPh(3))[S(AuPPh(3))(2)]] have been established by X-ray diffraction and show no short metal-metal interactions between the metallic centers.  相似文献   

16.
Reaction of [2.2]paracyclophane (pcp) with silver(I) trifluoroacetate (AgCF(3)CO(2)) and silver(I) pentafluoroproprionate (AgC(2)F(5)CO(2)) has led to isolation of three novel intercalation polymers: [Ag(4)(pcp)(CF(3)CO(2))(4)](C(6)H(6)) (1), [Ag(4)(pcp)(CF(3)CO(2))(4)](C(6)H(3)Me(3)) (2), and [Ag(4)(pcp)(C(2)F(5)CO(2))(4)](pcp) (3). Structure studies using single crystal X-ray diffraction have shown that all compounds contain two-dimensional layered frameworks based on cation-pi interactions, in which pcp exhibits an unprecedented micro-tetra-eta(2) coordination mode. Guest molecules which weakly interact with the host pcp via C-H.pi interactions are intercalated between layers. The guest-eliminated complexes (1a and 2a) and guest-reincorporated ones (1b or 1c and 2b or 2c), accompanied by small structural changes, were confirmed by (1)H NMR, thermogravimetric analysis, mass spectra, and X-ray powder diffraction patterns. The structural changes from 1 --> 1a --> 1c (=1) can take place reversibly in the process of exposure of 1a to benzene vapor. The original framework of complex 2 is also completely recovered by immersing 2a in mesitylene as well as exposing it to mesitylene vapor.  相似文献   

17.
The bis(trifluoromethyl)phosphanide ion, P(CF(3))(2)(-), decomposes slowly above -30 degrees C in CH(2)Cl(2) and THF solution. An increase of the thermal stability of the P(CF(3))(2)(-) moiety is observed if excess CS(2) is added. The P(CF(3))(2)(-) moiety is stabilized because of the formation of the bis(trifluoromethyl)phosphanodithioformate anion. Solutions of a [P(CF(3))(2)CS(2)](-) salt still act as a source of P(CF(3))(2)(-), even in the presence of excess of CS(2). The stable compound [18-crown-6-K][P(CF(3))(2)CS(2)] was characterized by multinuclear NMR spectroscopy, elemental analysis, and vibrational spectroscopy in combination with quantum chemical calculations. The thermally unstable P(C(6)F(5))(2)(-) ion decomposes even at -78 degrees C in solution giving polymeric material. The intermediate formation of the bis(pentafluorophenyl)phosphanide anion in the presence of excess of CS(2) allows the isolation of [18-crown-6-K][P(C(6)F(5))(2)CS(2)]. The novel compound crystallizes with one solvent molecule CH(2)Cl(2) in the monoclinic space group P2(1)/n with a = 1151.8(1) pm, b = 1498.1(2) pm, c = 2018.2(2) pm, beta = 102.58(1) degrees, and Z = 4. Optimized geometric parameters of the [P(C(6)F(5))(2)CS(2)](-) ion at the B3PW91/6-311G(d) level of theory are in excellent agreement with the experimental values.  相似文献   

18.
The relative Lewis basicities of six Al(ORF)4- ions, Al[OC(CH3)(CF3)2]4-, Al(OC(CF3)3]4-, Al(OCPh(CF3)2]4-, Al[OC[4-C6H4(tBu)](CF3)2]4-, Al(OC(Cy)(CF3)2]4-, and Al(OCPh2(CF3)]4-, have been determined by measuring their relative coordinating abilities towards Li+ in dichloromethane. The relative Li- Lewis basicities of the Al(ORF)4- ions are linearly related to the aqueous pKa values of the corresponding parent HORF fluoroalcohols. The Lewis basicity of Al[OCH(CF3)2]4- could not be measured because two of these anions can coordinate to one Li+ cation. The structures of LiAl[OCH(CF3)2]4 and [1-Et-3-Me-1,3-C3H3N2][Li[Al[OCH(CF3)2)4]2] were determined.  相似文献   

19.
The (eco)toxicity of the most common ionic liquid anions like [N(CN)(2)](-), [C(CN)(3)](-), [B(CN)(4)](-), [(CF(3)SO(2))(2)N](-), [(C(2)F(5))(3)PF(3)](-) was investigated in test systems of different trophic level. In the same order, and thus with increasing hydrophobicity, a trend of higher toxicity was found. Especially the [(C(2)F(5))(3)PF(3)](-) moiety poses a significant hazard towards aquatic organisms.  相似文献   

20.
Attempts to prepare the hitherto unknown Se(6)(2+) cation by the reaction of elemental selenium and Ag[A] ([A](-) = [Sb(OTeF(5))(6)](-), [Al(OC(CF(3))(3))(4)](-)) in SO(2) led to the formation of [(OSO)Ag(Se(6))Ag(OSO)][Sb(OTeF(5))(6)](2)1 and [(OSO)(2)Ag(Se(6))Ag(OSO)(2)][Al(OC(CF(3))(3))(4)](2)2a. 1 could only be prepared by using bromine as co-oxidant, however, bulk 2b (2a with loss of SO(2)) was accessible from Ag[Al(OC(CF(3))(3))(4)] and grey Se in SO(2) (chem. analysis). The reactions of Ag[MF(6)] (M = As, Sb) and elemental selenium led to crystals of 1/∞{[Ag(Se(6))](∞)[Ag(2)(SbF(6))(3)](∞)} 3 and {1/∞[Ag(Se(6))Ag](∞)}[AsF(6)](2)4. Pure bulk 4 was best prepared by the reaction of Se(4)[AsF(6)](2), silver metal and elemental selenium. Attempts to prepare bulk 1 and 3 were unsuccessful. 1-4 were characterized by single-crystal X-ray structure determinations, 2b and 4 additionally by chemical analysis and 4 also by X-ray powder diffraction, FT-Raman and FT-IR spectroscopy. Application of the PRESTO III sequence allowed for the first time (109)Ag MAS NMR investigations of 4 as well as AgF, AgF(2), AgMF(6) and {1/∞[Ag(I(2))](∞)}[MF(6)] (M = As, Sb). Compounds 1 and 2a/b, with the very large counter ions, contain isolated [Ag(Se(6))Ag](2+) heterocubane units consisting of a Se(6) molecule bicapped by two silver cations (local D(3d) sym). 3 and 4, with the smaller anions, contain close packed stacked arrays of Se(6) rings with Ag(+) residing in octahedral holes. Each Ag(+) ion coordinates to three selenium atoms of each adjacent Se(6) ring. 4 contains [Ag(Se(6))(+)](∞) stacks additionally linked by Ag(2)(+) into a two dimensional network. 3 features a remarkable 3-dimensional [Ag(2)(SbF(6))(3)](-) anion held together by strong Sb-FAg contacts between the component Ag(+) and [SbF(6)](-) ions. The hexagonal channels formed by the [Ag(2)(SbF(6))(3)](-) anions are filled by stacks of [Ag(Se(6))(+)](∞) cations. Overall 1-4 are new members of the rare class of metal complexes of neutral main group elemental clusters, in which the main group element is positively polarized due to coordination to a metal ion. Notably, 1 to 4 include the commonly metastable Se(6) molecule as a ligand. The structure, bonding and thermodynamics of 1 to 4 were investigated with the help of quantum chemical calculations (PBE0/TZVPP and (RI-)MP2/TZVPP, in part including COSMO solvation) and Born-Fajans-Haber-cycle calculations. From an analysis of all the available data it appears that the formation of the usually metastable Se(6) molecule from grey selenium is thermodynamically driven by the coordination to the Ag(+) ions.  相似文献   

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