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Research has been conducted on the P(CF (sub)3) (sub)2 (super)- ion. The ability of this ion to stabilize in solution has been investigated and the results indicate that this feature can affect the ion's capability to be used in nucleophilic displacement reactions.

This article describes the synthesis of some new perfluoro-alkyl-substituted tertiary oxonium ions and the effect of perfluoroalkyl substitution in the structure of the ions. Data show that replacement of one methyl group with trifluoromethyl group enhances the O-CH(sub)3 bond lengths by 0.037 angstrom and the sum of the C-O-C bond angles by approximately 4.5 degrees.

Results reveal that salts of bis(trifluoromethyl)phosphanide containing an anion [P(CF(sub)3)(sub)2](sup)- are very stable by virtue of low coordinating cations stabalizing salts with the anion.

Research demonstrates that chiral bidentate mercury ligands can be prepared by reacting mercury cyanide and bis(trifluoromethyl)phosphane. Data indicate that yield of the compounds is quantitatively significant with 18 valence electron complexes exhibiting thermal stability.

Experimental and theoretical studies were conducted to determine the thermochemical properties and nuclear magnetic resonance spectra of oxygen-coordinated donor-acceptor adducts of COCl2, COClF, and COF2 with AsF5 and SbF5. Results indicate that all the investigated adducts are unstable at ambient temperature. It was also observed that the strength of their oxygen bridges increases from COF2 ro COCl2 and from AsF5 to SbF5.

Multinuclear nuclear magnetic resonance spectroscopy was utilized to identify and characterize the difluoromethylated silver(I) and silver(III) compounds. Argentate(I) {Ag(CF2H)(CN)}- was formed through the difluoromethylation of {Ag(CN)2}- in the presence of acetyl chloride. Reaction of {Ag(CF3)(sub n)(CN)(sub 4-n)}- with Cd(CF2H)2 yielded stable argentates(III) containing both difluoromethyl and trifluoromethyl groups.

The stability of (trifluoromethyl)argentates(II) was analyzed by substituting the CF3 units with halides and alkyl groups. Thetrifluoromethylation of the dicyanoargenated(I) complex anion to [Ag(CF3)(CN)]- indicated the role of the Ag3+ ion in overcompensating the low ligand field strength of fluoride. The effects of Ag3+ also mediated the formation of a square-planar diamagnetic complex. Furthermore, the fluorination of the alkyl groups contributed to the stabilization of Ag(III).

The novel bis{bis(trifluoromethyl)phosphanido}argentate, [Ag{P(CF3)(sub 2)}(sub 2)](super -1), is obtained via the reaction of HP(CF3)(sub 2) with [Ag(CN)(sub 2)(super -1) and isolated as its [K(18-crown-6)] salt, which is the first example of a mononuclear diphosphanidoargentate. NMR spectroscopic evidence for the [Ag{P(CF3)P(CF3)(sub 2)}(sub 2)(super -1) ion is obtained in this study.

Research has been conducted on thermally unstable compound [Hg{P(C (sub)6 F (sub)5) (sub)2} (sub)2]. The authors report that this compound has been produced via the reaction of mercury cyanide with bis-(pentafluorophenyl)phosphane in N,N-dimethylformamide solution, and has been characterized via the use of multinuclear NMR spectroscopy.

Research has been conducted on P(CF (sub)3) (sub)2 (super)- ions. The authors demonstrate that the stabilization of these ions via coordination to the weak Lewis acid acetone leads to the single crystals of [18-crown-6-K]P(CF (sub)3) (sub)2.

Research has been conducted on pentafluorophenylphosphanes and their pentacarbonyl tungsten complexes. The synthesis of these compounds from the bromides carried out via the use of Me (sub)3 SnH and Bu (sub)3 SnH is described.

The first example of a mononuclear diphosphanidoargentate, bis{bis(trifluoromethyl)phosphanido}argentate, [Ag{P(CF3)2}2] , is obtained via the reaction of HP(CF3)2 with [Ag(CN)2]- and isolated as its [K(18-crown-6)] salt. When the cyclic phosphane (PCF3)4 is reacted with a slight excess of [K(18-crown-6)][Ag{P(CF3)2}2], selective insertion of one PCF3 unit into each silver phosphorus bond is observed, which on the basis of NMR spectroscopic evidence suggests the [Ag{P(CF3)P(CF3)2}2]- ion. On treatment of the phosphane complexes [M(CO)5PH(CF3)2] (M = Cr, W) with [K(18-crown-6)][Ag(CN)2], the analogous trinuclear argentates, [Ag{(µ-P(CF3)2)M(CO)5}2]-, are formed. The chromium compound [K(18-crown-6)][Ag{(µ-P(CF3)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) nm³, Z = 8. The symmetric anion, [Ag{(µ-P(CF3)2)Cr(CO)5}2]-, shows a nearly linear arrangement of the P-Ag-P unit. Although the bis(pentafluorophenyl)phosphanido compound [Ag{P(C6F5)2}2]- has not been obtained so far, the synthesis of its trinuclear counterpart, [K(18-crown-6)][Ag{(µ-P(C6F5)2)W(CO)5}2], was successful. ub>)2)W(CO)5}2]-: X-ray Crystal Structure of [K(18-crown-6)][Ag{(μ-P(CF3)2)Cr(CO)5}2]. [ABSTRACT FROM AUTHOR]

Synthetic routes to vanadium(V)-phosphinimide derivatives aro addressed. Initial synthetic efforts afforded the known compound formulated as VCI[sub 2](NPPh[sub 3])[sub 3] which was crystallographically determined to be the salt [VCI(NPPh[sub 3])[sub 3]]CI (1). Reactions of the vanadium-imide precursors VCI[sub 3](NAr) (Ar = Ph, C[sub 6]H[sub 3]-2,6-iPr[sub 2]) with R[sub 3]PNSiMe[sub 3] (R = Ph, iPr, tBu) afforded VCl[sub 2](NPh)(NPPh[sub 3]) (4), VCl[sub 2](NPh)(NPiPr[sub 3]) (5), VCl[sub 2](NPh)(NP tBu[sub 3]) (6), VCl[sub 2](NC[sub 6]H[sub 3]-2,6-iPr[sub 2])(NPPh[sub 3]) (7), VCI[sub 2](NC[sub 6]H[sub 3]-2,6-iPr[sub 2])(NP iPr[sub 3]) (8), and VCI[sub 2](NC[sub 6]H[sub 3]-2,6-iPr[sub 2])(NPtBu[sub 3]) (9) in yields ranging from 72% to 84%. Subsequent alkylation or arylation reactions resulted in VMe2(NC[sub 6]H[sub 3]-2,6-iPr[sub 2])(NPtBu[sub 3]) (10), VPh[sub 2](NPh)(NP tBu[sub 3]) (11), VPh[sub 2](NC[sub 6]H[sub 3]-2,6-iPr[sub 2])(NP iPr[sub 3]) (12), and VPh[sub 2](NC[sub 6]H[sub 3]-2,6-iPr[sub 2])(NPtBu[sub 3]) (13) while substitution reactions with Li[N(SiMe[sub 3])[sub 2]] and Li[SBn] gave VCI(N(SiMe[sub 3])[sub 2](NPh)(NPtBu[sub 3]) (14) and V(SBn)[sub 2](NC[sub 6]H[sub 3]-2,6iPr[sub 2])(NPtBu[sub 3]) (15)in yields ranging from 40% to 49% yield. Polarization of the N-P phosphinimide bond and V-N multiple bond character are evidenced by crystallographic data. [ABSTRACT FROM AUTHOR]

The stabilization of the P(CF[sub 3])[sub 2][sup -] ion by intermediary coordination to the very weak Lewis acid acetone gives access to single crystals of [18-crown-6-K]P(CF[sub 3])[sub 2]. The X-ray single crystal analysis exhibits nearly isolated P(CF[sub 3])[sub 2][sup -] 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[sub 3])[sub 2][sup -] ion to pentacarbonyl tungsten has only a minor effect on electronic and geometric properties of the P(CF[sub 3])[sub 2] moiety, while a strong increase in thermal stability of the dissolved species is achieved. The hitherto unknown P(C[sub 6]F[sub 5])[sub 2][sup -] 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[sub 6]F[sub 5])[sub 2]}(CO)[sub 5]], which is fully characterized. The tungstate, [W{P(C[sub 6]F[sub 5])[sub 2]}(CO)[sub 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)[sub 5]}[sub 2]{µ-P(C[sub 6]F[sub 5])[sub 2]}].THF exhibits a very tight arrangement of the two C[sub 6]F[sub 5] and two W(CO)[sub 5] groups around the central phosphorus atom. NMR spectroscopic investigations of the [{W(CO)[sub 5]}[sub 2]{µ-P(C[sub 6]F[sub 5])[sub 2]}]-ion exhibit a hindered rotation of both the C[sub 6]F[sub 5] and W(CO)[sub 5] groups in solution. [ABSTRACT FROM AUTHOR]

Examines the stabilization of the P(CF[sub3])[sub2]-ion being a reversible CS[sub2] adduct. Uses being a nucleophilic P(CF[sub3])[sub2]-source; Thermal stability of the ion; Formation of the bis(trifluoromethyl)phosphanodithioformate anion.

Discusses the thermally stability or unstability of silver. State at which silver is oxidized; Suitability of silver for certain identification by nuclear magnetic resonance techniques; Details on the study.

Unlike silanolates [SiR 3 O] - (R = alkyl, aryl), which have been intensely studied, the heavier derivatives [SiR 3 E] - (E = S, Se, Te) have been much less examined. Among such species, virtually nothing is known about perfluoroalkyl-substituted silylchalcogenolates. In this contribution, a convenient synthesis of tris(pentafluoroethyl)silylchalcogenolate salts [{(Et 2 N) 3 P═N} 3 PN(H) t Bu][Si(C 2 F 5 ) 3 E] (E = S, Se, Te; t Bu = tert -butyl) is presented. All representatives were isolated and fully characterized by multinuclear NMR spectroscopy, IR spectroscopy, mass spectrometry, elemental analysis, and X-ray diffraction studies. Furthermore, first reactivity studies of these novel species toward selected metal halide complexes were performed. In this course, metal complexes [HgPh{SSi(C 2 F 5 ) 3 }] ( 2 ) and [Au(PPh 3 ){SSi(C 2 F 5 ) 3 }] ( 3 ) were isolated and characterized.

Trifluoromethylation of [Ag(CN)(2)](-) with (CF(3))(2)Cd.diglyme yields [Ag(CF(3))(CN)](-). The anion is readily oxidized by bromine to the argentates(III), [Ag(CF(3))(n)(CN)(4-n)](-), n = 1-4. The stability of these species decreases with an increasing number of CN groups. Halogenation of these complexes with acetyl chloride or with bromine affords the moderately stable (n = 3) or unstable (n = 2) haloargentates of the type [Ag(CF(3))(n)X(4-n)](-), X = Cl or Br. Their dehalogenation with AgNO(3) in a donor solvent D gives the adducts [Ag(CF(3))(3)D] and [Ag(CF(3))(2)D(2)](+), respectively. Decomposition of most argentates(III) proceeds by reductive elimination of CF(3)X (X = Cl, Br, or CN), but ligand exchange with participation of the CF(3) groups is also observed. The latter is used to prepare Ag(CF(3))(3) derivatives from the readily accessible [trans-Ag(CF(3))(2)(CN)(2)](-) anion. The syntheses of methyl(trifluoromethyl)argentates(III) and of (cyclohexylethynyl)(trifluoromethyl)argentates(III) are accomplished by reaction of the cyanoargentates (n = 2, 3) with CH(3)MgCl or LiC&tbd1;CC(6)H(11), respectively. Often multinuclear ((109)Ag, (19)F, (13)C, (1)H) NMR data of transient and stable Ag(III) species establish unambiguously not only their constitution but also the square-planar coordination of the metal. Couplings to the spin-(1)/(2) silver nuclei are interpreted on the basis of 5s(Ag) orbital participation in competition with 4d orbital contributions to Ag-CF(3) bonding. Crystals of [PPh(4)][Ag(CF(3))(2)(CN)(2)] belong to the monoclinic space group C2/c, with a = 18.174(2) Å, b = 7.8881(8) Å, c = 18.881(2) Å, beta = 93.036(8) degrees, and Z = 4, whereas [PPh(4)][Ag(CF(3))(3)(CH(3))] crystallizes in the orthorhombic space group Pca2(1), with a = 24.941(3) Å, b = 7.2629(6) Å, c = 14.9985(14) Å, and Z = 4. The coordination environments of these two argentates are approximately square planar. The Ag-CF(3) bonds in the dicyano complex (2.105(4) Å) are distinctly longer than the Ag-CN linkages (2.013(3) Å). In the [Ag(CF(3))(3)(CH(3))](-) anion, the Ag-CH(3) distance (2.097(5) Å) is slightly shorter than the average Ag-CF(3) bond lengths (2.119(10) Å).