ortho-, meta- and para-nitrophenylgold(I) complexes

Treatment of [BzPh₃P][AuCl₂] with [Hg(x-C₆H₄NO₂)₂] (x = o, m, or p) gives anionic gold(I) complexes of the type [BzPh₃P][Au(R)Cl](R = o-, m- or p-C₆H₄NO₂, Bz = C₆H₅CH₂). The chloro ligand in [Au(o-C₆H₄NO₂)Cl]^? can be replaced by bromo or iodo ligands by use of NaBr or NaI. The anions [Au(R)Cl]^? react with neutral monodentate ligands, L, to give neutral mononuclear complexes [Au(R)L] (R = o-C₆H₄NO₂, L = PPh₃, AsPh₃; R = m-C₆H₄NO₂, L = PPh₃) and with 1,2-bis(diphenylphosphino)ethane (dpe) to give [Au₂(R)₂(dpe)] (R = o-C₆H₄NO₂). The corresponding [Au(p-C₆H₄NO₂)Cl]^? reacts with PPh₃ or AsPh₃ to give mixtures containing [AuClL]. The anionic ortho-nitrophenylgold(I) complex is much more stable than its meta- or para-nitrophenyl isomers. These are thought to be the first reports of nitrophenylgold(I) complexes.     

Synthesis and properties of aryldicyclopentadienyltitanium(III) compounds

The synthesis and properties of the compounds Cp₂TiR, with R = C₆H₅, o-, m-, p-CH₃C₆H₄, 2,6-(CH₃)₂C₆H₃, 2,4,6-(CH₃)₃C₆H₂, C₆F₅, CH₂C₆H₅, are described. Chemical and physical properties indicate that the R groups are σ-bonded to the titanium atom. The complexes are monomeric, with one unpaired electron per titanium atom. They are very air sensitive, and vary markedly in thermal stability; some of the compounds react with molecular nitrogen, to give complexes of the general formula (Cp₂TiR)₂N₂. Compounds CP₂TiR with R = alkyl could not be isolated.     

The thiolate anion as a nucleophile Part III. Reactions with various fluorobenzenes

The reactions of the fluorobenzenes, C₆F₅H, o-C₆H₂F₄, m-C₆H₂F₄, p-C₆H₂F₄, 1,3,5-C₆F₃H₃, 1,2,4-C₆F₃H₃, o-C₆F₂H₄, m-C₆F₂H₄, p-C₆F₂H₄ and C₆F₅H with thiolate anion nucleophiles RS^? (primarily MeS^?), have been studied in ethylene glycol/pyridine mixtures as a solvent. Multiple replacement of fluorine atoms was observed in the more highly fluorinated compounds, but in all cases two aromatic fluorine atoms were not replaced. Difluorobenzene and fluorobenzene did not react. The product orientations have been deduced from their NMR spectra. The mass spectra of the isomeric products C₆F₂H₃(SMe), C₆F₃H₂(SMe) and C₆F₂H₂(SMe)₂ have been examined.     

Polythiolated complexes. Part 2(1). Palladium(II) and platinum(II) derivatives of polyfluorophenylthiolates

Summary The preparation and characterization of the new thiolate complexes [M(SR)₂(SEt₂)₂] (M=Pt, R=C₆F₅ orp-C₆HF₄) and [M(SR)₂]_n (M=Pd, R=C₆F₅,p-C₆HF₄ orp-C₆H₄F; M=Pt, R=p-C₆H₄F) is discussed. The tendency to form polymeric, rather than monomeric species, varies as follows: Pd>Pt; C₆H₄F>C₆HF₄> C₆F₅. [Pt(SC₆F₅)₂(SEt₂)₂] has atrans square planar coordination.     

Synthesis and 197Au-Mössbauer spectroscopic studies of dihalo(pentafluorophenyl)(bidentate ligand)gold(III) complexes

Addition of a bidentate ligand (LL = 1,10-phenanthroline, o-phenylenebis(dimethylarsine)) to solutions of Au(C₆F₅)X₂(tht) (X = Cl, Br; tht = tetrahydrothiophene) leads to potentially five-coordinate gold(III) derivatives. ¹⁹⁷Au Mössbauer spectroscopy points, however, to four-coordinate square-planar complexes with a weak penta-coordination in the phen-containing derivatives. The complexes react with AgClO₄ to give four-coordinate cationic complexes of the types [Au(C₅F₅)X(LL)]ClO₄ or [Au(C₆F₅)(PPh₃)(LL)](ClO₄)₂.     

Carbonyl rhodium(I) complexes with α-diimines ligands

The reactions of [Rh(CO)₂Cl]₂ with α-diimines, RN=CR′-CR′=NR (R = c-Hex, C₆H₅, p-C₆H₄OH, p-C₆H₄CH₃, p-C₆H₄OCH₃, R′ = H; R = c-Hex, C₆H₅, p-C₆H₄OH, p-C₆H₄OCH₃; R′ = Me) in 2:1 Rh/R-dim ratio gave rise to ionic compounds [(CO)₂Rh.R-dim(R′,R′)][Rh(CO)₂Cl₂] which have been characterized by elemental analyses, electrical conductivity, ¹H-NMR and electronic and IR spectroscopy. Some of these complexes must involve some kind of metal-metal interaction. The complex [Rh(CO)₂Cl.c-Hex-dim(H,H)] has been obtained by reaction of [Rh(CO)₂Cl]₂ with the c-Hex-dim(H,H) ligand in 1:1 Rh/R-dim ratio. The reactions between [(CO)₂Rh.R-dim(H,H)][Rh(CO)₂Cl₂](R = c-Hex or p-C₆H₄OCH₃) with the dppe ligand have been studied. The known complex RhCl(CO)(PPh₃)₂ has been isolated from the reaction of [(CO)₂Rh.R-dim(H,H)]-[Rh(CO)₂Cl₂] (R = c-Hex or p-C₆H₄OCH₃) with PPh₃ ligand.     

Gas phase hydrogen/deuterium exchange reactions of fluorophenyl anions

Hydrogen/deuterium (H/D) exchange reactions of fluorophenyl and difluorophenyl anions (C₆H₄F^?, o-C₆H₃F ₂ ^? , m-C₆H₃F ₂ ^? , p-C₆H₃F ₂ ^? ) have been studied using the flowing afterglow-selected ion flow tube technique. The C₆H₄F^? anion exchanges all hydrogens for deuterium upon reaction with D₂O. The difluorophenyl anions o-, m-, and p-C₆H₃F ₂ ^? exchange three, two, and one hydrogen, respectively, with D₂O, whereas they undergo one, two, and three H/D exchanges, respectively, with CH₃OD. The structures of the anions and the isotope exchange dynamics within the intermediate ion-dipole complexes are discussed using ab initio molecular orbital calculations. Calculated values for the proton affinities of the most stable anions are 385.2, 378.0, 371.9, and 378.2 kcal/mol for C₆H₄F^?, o-C₆H₃F ₂ ^? , m-C₆H₃F ₂ ^? , and p-C₆H₃F ₂ ^? , respectively, in excellent agreement (within 2 kcal/mol) with the previous experimental values for the acidities of the corresponding fluorobenzenes. The H/D exchange results are explained by the energy differences of the intermediate DO^? and CH₃O^? species within the ion-dipole complexes; CH₃O^? is mobile within the “hot” intermediate complex, whereas DO^? is nearly “frozen” within the complex and cannot migrate across the barriers caused by the fluorine atoms or by the π electrons.     

Cationic palladium(II) complexes involving unprecedented O-coordination of acetylmethylenetriphenylphosphorane

Cationic pentafluorophenyl palladium(II) complexes of the type [Pd(C₆F₅)L₂(APPY)]ClO₄ (L = PPh₃, PBu₃ⁿ; L₂ = bipy and A acetylmethylenetriphenylphosphorane) have been prepared by addition of APPY to the perchlorato complexes [Pd(OClO₃)(C₆F₅)L₂]; the APPY ligand is O-coordinated, which is unprecedented in keto-stabilized ylide complexes of palladium.The neutral complex Pd(C₆F₅)(Cl)(tht)(APPY) has been made by addition of APPY to the binuclear complex Pd₂(μ-Cl)₂(C₆F₅)₂(tht)₂ (tht = tetrahydrothiophene); in which the APPY ligand shows the normal C-coordination.     

Binuclear dinitrogen complexe of aryl- and benzyldicyclopentadienyltitanium(III) compounds

The preparation of the deep-blue diamagnetic dinitrogen complexes (Cp₂TiR)₂N₂ with R=C₆H₅, o-, m-, p-CH₃C₆H₄, C₆F₅, CH₂C₆H₅ is described. Their chemical and physcial properties confirm the formulation in which the R groups are σ-bonded to the Cp₂Ti moiety, and the two nitrogen atoms are equivalent. The heats of formation of the complexes from Cp₂TiR and N₂ in toluene have been determined from spectrophotometric data; for R=C₆H₅, o-, m-, p-CH₃C₆H₄, C₆F₅, CH₂C₆H₅, the values are ?18, ?9, ?17, ?20, ?17 and ?14 kcal·mol^?1, respectively. The solid complexes vary markedly in thermal stability, and are extremely air sensitive. The complexed nitrogen can be completely reduced with sodium naphthalene; after hydrolysis of the products, NH₃ and N₂H₄ are obtained. In the thermolysis of the solids, some of the nitrogen is reduced.     

Thiocarboxylato Complexes of Biscyclopentadienyl and Bisindenyl Titanium (IV)

Reactions of biscyclopentadienyl (and bisindenyl) titanium (IV) dichlorides with sodium salts of various thiocarboxylic acids in tetrahydrofuran medium, yield the complexes of the general formula (D) ²Ti(SCOR) ² where D is cyclopentadienyl or indenyl group and R? H, CH₃, C₂H₅, C⁴H⁵ or p-C⁴H⁴CH³ group. The foul smelling complexes are monomeric in nature. The IR spectra, thermal stabilities and Some physical characteristics of these complexes have been studied.     

Mono- and bisphenoxy derivatives of bis(indenyl)zirconium(IV)

A series of (C₉H₇)₂Zr(OAr)Cl and (C₉H₇)₂Zr(OAr)₂ complexes, where Ar = C₆H₅, p-ClC₆H₄, α-C₁₀H₇, or β-C₁₀H₇, have been synthesised by the reaction of bis(indenyl)zirconium(IV)-dichloride with an appropriate phenol in a 1:1 and 1:2 molar ratio in refluxing benzene in the presence of triethylamine. These complexes have been characterised by elemental analyses, conductance measurements and spectral (IR, ¹H NMR and electronic) studies.     

Transition metal derivatives of arenediazonium ions: XIV. Reactions of arenediazomolybdenum(II) complexes with neutral and anionic Lewis bases

The reactions of arenediazomolybdenum(II) complexes such as [(η-C₅H₅)Mo(N₂C₆H₄CH₃-p)I₂]₂, (η-C₅H₅)Mo(CO species with neutral and anionic monodentate or chelating ligands have been investigated. The new arenediazo complexes isolated from these reactions include neutral species such as (η-C₅H₅)Mo(PPh₃)(N₂C₆H₄CH₃-p)I₂ and (η-C₅H₅)Mo(N₂C₆H₄CH₃-p) cations of the type [η-C₅H₅)Mo(bipy)(N₂C₆H₄CH₃-p)I]⁺ and the anion [(η-C₅H₅)Mo(N₂C₆H₄CH₃-p)I₃]^?. The structures of the new complexes are discussed.     

Gold(III)pentafluorophenylarylazoimidazole: Synthesis and spectral (H, C, COSY, HMQC NMR) characterisation

Reaction of [Au^III(C₆F₅)₃(tht)] with RaaiR′ in dichloromethane medium leads to [Au^III(C₆F₅)₃ (RaaiR′)] [RaaiR′=p-R-C₆H₄-N=N-C₃H₂-NN-l-R′, (1-3), R = H (a), Me (b), Cl (c) and R′= Me (1), CH₂CH₃ (2), CH₂Ph (3), tht is tetrahydrothiophen]. The nine new complexes are characterised by ES/MS as well as FAB, IR and multinuclear NMR (¹H,¹³C,¹⁹F) spectroscopic studies. In addition to dimensional NMR studies as¹H,¹H COSY and¹H¹³C HMQC permit complete assignment of the complexes in the solution phase.     

The solid state structure of arene-mercury(II) complexes from magic-angle spinning carbon-13 NMR and the solution carbon-13 NMR of some complexes of mercury(II) with arenes having bulky aliphatic substituents

The cross-polarization magic angle spinning ¹³C NMR spectra of Hg(SbF₆)₂ - 2 Arene (Arene = C₆HMe₅, 1,2,4,5-C₆H₂Me₄, 1,2,3,4-C₆H₂Me₄, or C₆H₆) have been measured. The spectra of the complexes of C₆HMe₅ and 1,2,4,5-C₆H₂Me₄ are consistent with static η¹-bonding of the mercury to the arene at an unsubstituted carbon atom, while the spectra of the 1,2,3,4-C₆H₂Me₄ and C₆H₆ complexes show the arene to have time-averaged C_s or C₂, and C₆ symmetry respectively, at the temperature of measurement (300 K).The reduced temperature ¹³C NMR spectra of Hg(Arene)_n²⁺ (n = 1 or 2; Arene = 1,3,5-C₆H₃R₃ (R = Me, i-Pr, or t-Bu)) in SO₂ solution are also reported and affirm that in these intramolecularly mobile species the mercury bonds in an η¹-manner, with unsubstituted aryl carbon atoms being the strongly preferred point of mercury attachment. This site preference is further demonstrated by the solution ¹³C NMR spectra of Hg(Arene)_n²⁺ (Arene = 1,2,3,4-C₆H₂-Me₄, n = 1 or 2; Arene = 1,4-C₆H₄R₂, R = Me or t-Bu, n = 1). The spectra of the 1,4-C₆H₄R₂ complexes and Hg(p-C₆H₄-t-BuMe)²⁺ provide clear evidence for steric influence of the binding site.Like Hg(C₆Me₆)₂²⁺, but unlike most of the complexes of substituted benzenes which have been studied, Hg(1,3,5-C₆H₃-i-Pr₃)₂²⁺ exchanges only slowly with excess free ligand.     

From hypervalent xenon difluoride and aryliodine(III) difluorides to onium salts: Scope and limitation of acidic fluoroorganic reagents in the synthesis of fluoroorgano xenon(II) and iodine(III) onium salts

Fluorinated organodifluoroboranes R_fBF₂ are in general suitable reagents to transform XeF₂ and RIF₂ into the corresponding onium tetrafluoroborate salts [R_fXe][BF₄] and [R(R_f)I][BF₄], respectively. (4-C₅F₄N)BF₂ and trans-CF₃CFCFBF₂ which represent boranes of high acidity form no Xe-C onium salts in reactions with XeF₂ but give the desired iodonium salts with RIF₂ (R = C₆F₅, o-, m-, p-C₆FH₄). The reaction of (4-C₅F₄N)BF₂ with XeF₂ ends with a XeF₂-borane adduct. C₆F₅Xe(4-C₅F₄N), the first Xe-(4-C₅F₄N) compound, was obtained when C₆F₅XeF was reacted with Cd(4-C₅F₄N)₂. We describe the synthesis of (4-C₅F₄N)IF₂ and reactions of (4-C₅F₄N)IF₂ and C₆F₅IF₂ with (4-C₅F₄N)BF₂. Analogous to [(4-C₅F₄N)₂I][BF₄] and [C₆F₅(4-C₅F₄N)I][BF₄] aryl(perfluoroalkenyl)iodonium salts [R(R′)I][BF₄] were obtained from RIF₂ (R = C₆F₅, o-, m-, p-C₆FH₄) and R′BF₂ (R′ = trans-CF₃CFCF, CF₂CF). The gas phase fluoride affinities pF⁻ of selected fluoroorganodifluoroboranes R_fBF₂ and their hydrocarbon analogs are calculated (B3LYP/6-31+G^*) and discussed with respect to their potential to introduce R_f-groups into hypervalent EF₂ bonds. Four aspects which influence the transformation of hypervalent EF₂ bonds (E = Xe, R′I) under the action of Lewis acidic reagents RAF_n−1 (A = B, P; n = 3, 5) into the corresponding [RE][AF_n+1] salts are presented and the important role of the acidity is emphasized. Fluoride affinities may help to plan the introduction of organo groups into EF₂ moieties and to expand the types of acidic reagents. Thus C₆H₅PF₄ with a pF⁻ value comparable to that of R_fBF₂ compounds is able to introduce the C₆H₅ group into RIF₂ (R = C₆F₅, p-C₆FH₄).     

Neutral and anionic pentafluorophenyl complexes of palladium and platinum(II) and their reactivity towards amines

Summary The (n-Bu₄N)[M(C₆F₅)₃(CNR)] complexes (M=Pd or Pt; R=p-Tolyl, Me, Cy ort-Bu, prepared from (n-Bu₄N)[M(C₆F₅)₃(tht)] (tht = tetrahydrothiophene) and the appropriate isocyanide, RNC, prove to be unreactive towards benzylamine or MeOH. Thetrans-[Pd(C₆F₅)₂(CNR)₂] complexes react slowly with benzylamine to give the corresponding carbene complexestrans-[Pd(C₆F₅)₂{C(NHR)(NHBz)}₂], the rate of the reaction decreasing in the order:p-Tolyl > Me > Cy t-Bu (for R=t-Bu the carbene complex cannot be prepared). In the corresponding Pt complexes a marked decrease in reactivity is observed and only the most reactive isonitrile complex (R=p-Tolyl) gives the carbene complextrans-[Pt(C₆F₅)₂{C(NHTolyl-p)(NHBz)}_2}. Thecis-[M(C₆F₅)₂(CNTolyl)₂] complexes do not show any change in reactivity compared to the correspondingtrans-complexes, and givecis[M(C₆F₅)₂{C(NHTolyl-p)(NHBz)}₂].     

Bi- and tetranuclear polyfluorophenyl-bridged gold(I) complexes

The reaction of RAuL (R = 2,4,6-C₆F₃H₂, 3,6-C₆F₂H₃, 4-C₆FH₄ or 3-CF₃C₆H₄; L = PPh₃ or AsPh₃) or RAudpeAuR with inorganic acids HA (A = ClO₄, BF₄ or PF₆) leads to binuclear complexes of the types [R(AuL)₂]A or [R(Au₂dpe)]BF₄. Similarly, reaction of NBu₄[Au(2,4,6-C₆F₃H₂)₂] with HPF₆ yields the tetranuclear complex Au₄(2,4,6-C₆F₃H₂)₄. Addition of RAuL to solutions obtained by treating ClAuL with AgA also gives compounds of the type [R(AuL)₂]A.     

Diorganotin(VI) complexes of N-acetylamino acids

Sixteen complexes of general formula R₂SnL₂ and R₂(L)SnOSn(L)R₂ (where L = N-acetyl-L-leucine or N-acetyl-L-phenylalanine) R = CH₃, C₂H₅, n-C₄H₉, or n-C₈H₁₇) have been prepared by interaction between the ligand and R₂SnO in 2:1 or 1:1 molar ratio. The complexes were characterized by IR, ₁H NMR and ¹¹⁹Sn Mössbauer spectroscopy. All the 2:1 complexes are assigned six-coordinate, distorted octahedral geometry with chelating carboxylate groups, while the 1:1 complexes have oxygen-bridged binuclear five-coordinate, trigonal-bipyramidal configurations. The amido ?CO and ?NH groups are hydrogen bonded in the solid state.     

Synthesis of compounds with polymetallic chains including boron atoms of a carborane cage

Compounds with B-Hg-Ge or Ge-Hg-B-B-Hg-Ge chains in which the boron atoms are members of a carborane cage have been prepared by treatment of the digermane (C₆F₅)₃GeGeEt₃, with B-mercurated derivatives of the carboranes m-C₂H₂B₁₀H₉HgX (X = Cl, OCOCF₃) and m-C₂H₂B₁₀H₈(HgOCOCF₃)₂. Treatment of HGe(C₆F₅)₂Ge(C₆F₅)₂H with methyl(m-carboran-9-yl)mercury resulted in a compound with a B-Hg-Ge-Ge-Hg-B chain containing two carborane cages at the ends of the chain. The compound prepared can take part in oxidative insertion of Pt(PPh₃)_n (n = 3,4) to give the chains B-Hg-Pt-Ge, Ge-Pt-Hg-B-B-Hg-Ge and B-Hg-Pt-Ge-Ge-Pt-Hg-B.     

Polyfluorophenylgold(I) complexes

Neutral polyfluorophenyl complexes of the type RAuL and RAuL-LAuR and anionic complexes of the type [AuR₂]^? (R = 2,3,5,6-C₆F₄H, 2,4,6-C,F₃H₂, 3,6-C₆F₂H₃, 4-C₆ FH₄ or 3-CF₃C,H₄) are obtained by the reaction of ClAuL (L = PPh₃, P(cyclohexyl)₃, AsPh₃ or tetrahydrothiophen; L-L = Ph₂PCH₂PPh₂ or Ph₂PCH₂CH₂PPPh₂) with an organolithium derivative and/or the replacement of the initial ligands L by other mono- or bi-dentate ligands.The outcome of the reaction of [AuR₂]^? with [Au(PCy₃)₂]⁺ (Cy = cyclohexyl), depends on the nature of the ligand R; thus with R = 3,6-C₆,F₂H₃ the product is [Au(PCy₃)₂][AuR₂], while with R = 2,4,6-C₆F₃H₂, the product is [Au(PCy₃)(2,4,6-C₆F₃H₂)].