Some reactions of π-cyclopentadienylbis(triphenylphosphine) rhodium(I)

Reactions of π-cyclopentadienylbis(triphenylphosphine)rhodium(I) (I) with alkyl halides, olefins, acetylenes, carbon disulfide and elementary sulfur have been investigated. Methyl iodide gives the oxidative-addition product [πC₅H₅ Rh(PPh₃)₂CH₃]I but isopropyl iodide produces the alkyl substituted-cyclopentadienyl complex (π-i-C₃H₇C₅H₄)Rh(PPh₃)I₂. Under a nitrogen atmosphere, olefins and acetylenes give compounds of the composition π-C₅H₅ Rh(PPh₃)(L) (L = CH₂—CHCN, CH₂—CHCO₂CH₃, CH₃O₂—CCOO₂CH₃).In the presence of air, however, complexes of the composition π-C₅H₅Rh(L)₂ (L = CH₂—CHCN, CH₂—CHCO₂CH₃, CH₂—C(CH₃)CN) and π-C₅H₅Rh(L)₃ (L = CH₃O₂ CC—CCO₂ CH₃, PhC—CCO₂ CH₃) are formed. The reaction of carbon disulfide or sulfur with (I) also gives the compounds π-C₅H₅Rh(PPh₃)(L) (L = CS₂, CS₃, S₅).     

Oxygen-Bridged Ga2(Et)3(OTeF5)3 and the Weakly Coordinating Anions [Ga(Et)(OTeF5)3]− and [Ga(OTeF5)4]−

Salts of the weakly coordinating anions [Ga(OTeF₅)₄]⁻ as well as [Ga(Et)(OTeF₅)₃]⁻ and the neutral Ga₂(Et)₃(OTeF₅)₃ were synthesized and characterized by spectroscopic methods and single-crystal X-ray diffraction. Ga₂(Et)₃(OTeF₅)₃ was formed by treating GaEt₃ with pentafluoroorthotelluric acid (HOTeF₅) and reacted with PPh₄Cl and CPh₃Cl to [PPh₄][Ga(Et)(OTeF₅)₃] and [CPh₃][Ga(Et)(OTeF₅)₃]. In contrast, Ag[Ga(OTeF₅)₄] was prepared from AgOTeF₅ and GaCl₃ and was used as a versatile starting material for further reactions. Starting with Ag[Ga(OTeF₅)₄] the substrates [PPh₄][Ga(OTeF₅)₄] and [CPh₃][Ga(OTeF₅)₄] were formed from PPh₄Cl and CPh₃Cl.     

Kinetic Study of the Ru(II) Catalyzed Oxidation of Pentacyanoferrate(ll) Complexes by Peroxydisulfate

The oxidation reactions of Fe(CN)₅L^3? (L = 4-ampy, py, dpa) complexes by S₂O₈^2? were catalyzed upon the addition of a trace amount of Ru(NH₃)₅L′²⁺ (L′ = pz, py or dcb) complex, and the reaction becomes zero-order in Fe(II). The reaction time is ～10² fold faster than the simple Fe(CN)₅L^3?-S₂O₈^2? system. The mechanism of this Ru(II) catalyzed redox reaction is proposed as Ru(NH₃)₅L′²⁺ + 1/2 S₂O₈^2? → Ru(NH₃)₅L′³⁺ + SO₄^2? Ru(NH₃)₅L′³⁺ + Fe(CN)₅L^3? ? Ru(NH₃)₅L′²⁺ + Fe(CN)₅L^2?     

Reactive intermediates in the photolysis of cyclopentadienylcobalt(I) dicarbonyl and in the reduction of cyclopentadienylcobalt(III) carbonyl diiodide

Photolysis of (C₅H₅)Co(CO)₂ (I) in toluene or petroleum ether solution at ?78°C generates the unsaturated monocarbonyl species (C₅H₅)Co(CO), which was identified in solution by its IR spectrum. At room temperature, this monocarbonyl can associate with excess I to give (C₅H₅)₂Co₂(CO)₃, or dimerize to (C₅H₅)₂Co₂(CO)₂. The latter is stable as a solid, but in solution it is slowly converted to the insoluble trimer (C₅H₅)₃Co₃(CO)₃. (C₅H₅)₂Co₂(CO)₂ is symmetrically cleaved by phosphines to (C₅H₅)Co(CO)(PR₃), while diolefins bring about unsymmetrical cleavage to give (C₅H₅)Co(diolefin) and (C₅H₅)Co(CO)₂.     

Thermal studies on the decomposition of aquopentamminecobalt(III) hexathiocyanatochromate(III)

The decomposition of [Co(NH₃)₅H₂O] [Cr(NCS)₆] has been studied using DSC and TG. The first step involves the loss of H₂O and NH₃ in a first-order process to produce [(NH₃)₅Co(SCN)₃Cr(NCS)₃]. A second step involves the loss of HSCN. Activation energies are presented and the mechanisms of the reactions are discussed in comparison to analogous cyanide complexes.     

Kinetics of the Reductions of (Ethylenediaminetetraacetato)cobaltate(III) by 4,4-Dipyridylamine Complexes of Pentacyanoferrate(II) and Pentaammineruthenium(II)

The reactions of Fe(CN)₅dpa^3? and Ru(NH₃)₅dpa²⁺ (dpa = 4,4′-dipyridylamine) with Co(edta)^? have been investigated kinetically. For Fe(CN)₅dpa^3? complex, a linear relationship was observed between the pseudo-First-order rate constants and the concentrations of Co(edta) which leads to a specific rate 0.876 ± 0.006 M^?1S^?1 at T = 25°C., μ = 0.10 M and pH = 8.0. For the Ru(NH₃)₅dpa²⁺ system, the plots k_obs vs [Co(edta)^?] become nonlinear at concentrations of Co(edta) greater than 0.01 M and the reaction is interpreted on the basis of a mechanism involving the formation of an ion pair between Ru(NH₃)₅dpa²⁺ and Co(edta)^? followed by electron transfer from Ru(II) to Co(III). The nonlinear least squares fit of the kinetic results shows that Q_ip = 10.6 ± 0.7 M^?1 and k_et = 93.9 ± 0.7 s^?1 at pH = 8.0,μ = 0.10 M and T = 25°C.     

Intermediates in associative phosphine substitution reactions of (η5-C5H5)W(CO)2(NO)

The reaction of (η⁵-C₅H₅)W(CO)₂(NO), 6W, with P(CH₃)₃ proceeds rapidly at 25°C to give (η⁵-C₅H₅)W(CO)(NO)[P(CH₃)₃], 7W. The rate of formation of 7W was found to be 4.48 × 10^?2M^?1 [6W] [P(CH₃)₃] at 25.0°c in THF. In neat P(CH₃)₃ at ?23°C, 6W is converted to (η¹-C₅H₅)W(CO)₂(NO)[P(CH₃)₃]₂, 8W. In dilute solution, 8W decomposes to initially give a 2:1 mixture of 6W and 7W. The mixture is then converted to 7W. The reaction of (η⁵-C₅H₅)Mo(CO)(NO), 6Mo, with P(CH₃)₃ is 6.1 times faster than that of the tungsten analog.     

Preparation of new (η5-C5H4CH3)Mn(NO)(PPh3) and (η7-C7H7)Mo(CO)-(PPh3) complexes

The complex (η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)I has been prepared by the reaction of NaI with [(η⁵-C₅H₄CH₃)Mn(NO)(CO)(PPh₃)]⁺ and also by the reaction of [(η⁵-C₅H₄CH₃)Mn(NO)(CO)₂]⁺ with NaI followed by PPh₃. This iodide compound reacts with NaCN to yield (η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)CN which is ethylated by [(C₂H₅)₃O]BF₄ to yield [(η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)(CNC₂H₅)]⁺. Both [(η⁵-C₅H₄CH₃)Mn(NO)(CO)₂]⁺ and [(η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)(CO)]⁺ react with NaCN to yield [(η⁵-C₅H₄CH₃)Mn(NO)(CN)₂]^?. This anion reacts with Ph₃SnCl to yield cis-(η⁵-C₅H₄CH₃)Mn(NO)(CN)₂SnPh₃ and with [(C₂-H₅)₃O]BF₄ to yield [(η⁵-C₅H₄CH₃)Mn(NO)(CNC₂H₅)₂]⁺. The reaction of (η⁵-C₅-H₄CH₃)Mn(NO)(PPh₃)I with AgBF₄ in acetonitrile yields [(η⁵-C₅H₄CH₃)Mn-(NO)(PPh₃)(NCCH₃)]⁺. The complex (η⁵-C₅H₄CH₃)Mn(NO)(CO)I, produced in the reaction of [(η⁵-C₅H₄CH₃)Mn(NO)(CO)₂]⁺ with NaI, is not stable and decomposes to the dimeric complex (η⁵-C₅H₄CH₃)₂Mn₂(NO)₃I for which a reasonable structure is proposed. Similar dimers can be prepared from the other halide salts. The reaction of (η⁷-C₇H₇)Mo(CO)(PPh₃)I with NaCN yields (η⁷-C₇-H₇)Mo(CO)(PPh₃)CN which is ethylated by [(C₂H₅)₃O]BF₄ to yield [(η⁷-C₇H₇)-Mo(CO)(PPh₃)(CNC₂H₅)]⁺. The interaction of this molybdenum halide complex with AgBF₄ in acetonitrile and pyridine yields [(η⁷-C₇H₇)Mo(CO)(PPh₃)-(NCCH₃)]⁺ and [(η⁷-C₇H₇)Mo(CO)(PPh₃)(NC₅H₅)]⁺, respectively. Both (η⁵-C₅-H₄CH₃)Mn(NO)(PPh₃)I and (η⁷-C₇H₇)Mo(CO)(PPh₃)I are oxidized by NOPF₆ to the respective 17-electron cations in acetonitrile at ?78°C but revert to the neutral halide complex at room temperature. This result is supported by electrochemical data.     

Synthesis,characterization and structure of the Bis(methyl-cyclopentadienyl)vanadium(IV) carboxylates

The 1,1’-dimethylvanadocene dichloride ((C₅H₄CH₃)₂VCl₂) reacts in aqueous solution with various carboxylic acids giving two different types of complexes. The 1,1’-dimethylvanadocene complexes of monocarboxylic acids (C₅H₄CH₃)₂V(OOCR)₂ (R=H,CCl₃, CF₃, C₆H₅) contain two monodentate carboxylic ligands, whereas oxalic and malonic acids act as chelate compounds of the formula (C₅H₄CH₃)₂V(OOC-A-COO) (A=−, CH₂). The structure of the (C₅H₄CH₃)₂ V(OOCCF₃)₂ complex was determined by single crystal X-ray diffraction analysis. The isotropic and anisotropic EPR spectra of all the complexes prepared were recorded. The obtained EPR parameter values were found to be in agreement with proposed structures.     

Neutral bis(pentafluorophenyl)triphenylarsinegold(III) complexes

The complexes XAu(C₆F₅)₂AsPh₃ have been prepared by substitution of chloro- or perchlorato-bis(pentafluorophenyl)triphenylarsinegold(III) with alkali or with silver salts MX (X = NO₃, CH₃COO, NO₂, CF₃COO, CN, SCN, N₃ and C₆H₅COO). Decomposition of the nitrato or acetato complex leads to C₆F₅AuAsPh₃.     

Ab initio investigation of the synthesis of (3-(2,3,4,5-tetramethylcyclopentadienyl)propoxy)titanium dichloride

The two-step synthesis of [η⁵:η¹-C₅Me₄(CH₂)₃O]TiCl₂ from [C₅Me₄(CH₂)₃OMe]TiCl₃ is investigated through molecular orbital calculations. Results of ab initio, restricted Hartree–Fock calculations at the 6-311G(d) basis set level are reported for the reactants, products, and an intermediate, [C₅Me₄(CH₂)₃OMe]TiCl₂(CHPPh₃). These results provide insight into the mechanism of the second reaction, which is found to be a charge-controlled intermolecular nucleophilic attack. The nature of the titanium–ylid bond in the intermediate complex is also reported.     

Photochemical reactions of (CO)2 (PPh3)MnC5H4Fe(CO)2C5H5 and (CO)2(PPh3)MnC5H4COFe(CO)2C5H5 with PPh3

Conclusions The photochemical reactions of (CO)₂(PPh₃)MnC₅H₄Fe(CO)₂C₅H₅ and (CO)₂(PPh₃)MnC₅H₄COFe(CO)₂C₅H₅ with PPh₃ gave the products of replacing the CO on the Fe atom by PPh₃: respectively (CO)₂(PPh₃)MnC₅H₄Fe (CO)(PPh₃)C₅H₅ and (CO)₂(PPh₃)MnC₅H₄COFe(CO)(PPh₃)C₅H₅.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2813–2815, December, 1977.     

Dihaloperhaloaryl(triphenylarsine)gold(III) Complexes

When C₆Cl₅AuAsPh₃ reacts with halogens, oxidation of the gold(I) complex and formation of X₂Au(C₆Cl₅)AsPh₃ (X = Cl, Br, I) take place. However, when C₆F₅AuAsPh₃ reacts with halogens, oxidation is only observed in the case of Cl₂, whilst I₂ (totally) and Br₂ (partially) split the AuC bond. This behaviour is contrary to that observed with C₆F₅AuPPh₃ and halogens, where the tendency to split the AuC bond decreases in the sequence Cl>B>I.     

Mixed halodicyclopentadienyl-niobium(V) and -tantalum(V)

Oxidation of (η⁵-C₅H₅)₂MCl (M = Nb, Ta) with 1 mol of Cl₂, Br₂ or I₂ gives (η⁵-C₅H₅)₂MClX₂ whereas the reaction with an excess of the halogen gives the cationic complexes [η⁵-C₅H₅)₂MClX]⁺ X₃^? (X = Br, I). Similar oxidation of (η⁵-C₅H₅)₂MCl₂ with 0.5 mol of halogen gives (η⁵-C₅H₅)₂MCl₂X complexes, but if the halogen is used in excess cationic [η⁵-C₅H₅)₂MCl₂]⁺ X₃^? (X = Br, I; M = Ta and X = I, M = Nb) are obtained. All these complexes can also be obtained simultaneously by oxidizing (η⁵-C₅H₅)₄M₂Cl₃, and the separation is fairly easy in most cases. Conductivity and IR and NMR data are discussed.     

Carbonyl-organocobalt(I) and -(II) complexes

Passage of CO through solutions of complexes (C₆F₅)₂CoL₂ gives carbonyl derivatives (C₆F₅)₂CoL₂(CO) (L₂ = 2 PEt₃, 2 P-n-Bu₃, 2 PPh₃, Ph₂PCH₂CH₃PPh₂). The properties of these compounds are described.The compounds are also produced by treating solutions of (C₆F₅)₂Co-(dioxane)₂ with CO, but a simultaneous reduction to (C₆F₅)Co(CO)₄ takes place. Treatment of the latter complex with monodentate ligands gives substitution products (C₆F₅)Co(CO)₃L (L = PEt₃, P-n-Bu₃, PPh₃) all of which are monomeric, whereas the addition of Ph₂PCH₂CH₂PPh₂ gives the dimer (C₆F₅)(CO)₂CoLLCo(CO)₂(C₆F₅). The properties of these compounds are discussed.     

Reaction of cationic palladium(II) and rhodium(I) complexes with the t-butylperoxy anion: Preparation of t-butylperoxo-palladium(II) and -rhodium(I) complexes

Treatment of the coordinatively unsaturated cationic complexes, [(η-C₃H₅)(Ph₃P)₂Pd^II]PF₆ and [(1,5-COD)₂Rh^I]BF₄, with potassium t-butylperoxide in dichloromethane gives the t-butylperoxometal complexes; (η-C₃H₅)(Ph₃P)(t-BuOO)Pd^II and [(1,5-COD)(t-BuOO)Rh^I](KBF₄), via nucleophilic attack by t-BuOO⁻ on the cationic metal center.     

Neodymium(iii) and dysprosium(iii) naphthalene hydride complexes

Reactions of neodymium and dysprosium diiodide hydrides LnI₂H with lithium naphthalenide in THF furnished heterobimetallic naphthalene hydride clusters (C₁₀H₈)₃Ln₅Li₅H₁₄ (Ln = Nd, Dy). Treatment of the latter with hexamethyldisilazane in THF leads to the removal of lithium in the form of LiN(SiMe₃)₂ and the formation of compounds of the composition (C₁₀H₈)₃Ln₅H₉ (Ln = Nd, Dy). All the clusters obtained were isolated as black pyrophoric powders insoluble in THF and other organic solvents. Reactions of (C₁₀H₈)₃Nd₅Li₅H₁₄ and (C₁₀H₈)₃Nd₅H₉ with cyclopentadiene lead to Cp₃Nd(THF).     

π-Cyclopentadienyls of nickel(II) : XIII. The preparation and properties of the compounds π-C5H5NiPBu3SC(S)X (X = OR,R and NRH) and π-C5H5NiPBu3SC(O)NRH

Compounds of the type π-C₅H₅NiPBu₃SC(S)X (X = R, OR and NRH) are obtained from reactions between [π-C₅H₅Ni(PBu₃)₂]⁺Cl^? and SC(S)X^? in aqueous solution. Compounds such as π-C₅H₅NiPBu₃SC(S)NRH are also obtained by reactions of π-C₅H₅NiPBu₃SH with RNCS.Reactions of C₆H₅NCS with π-C₅H₅NiPBu₃SEt or [π-C₅H₅NiPBu₃S(CH₂)_n]₂ (n = 1, 2 and 3) give π-C₅H₅NiPBu₃[SC(NC₆H₅)SC₂H₅] or [π-C₅H₅NiPBu₃ {SC(NC₆H₅)S(CH₂)_n}]₂ respectively.Similar reactions of π-C₅H₅NiPBu₃SH and RNCO given π-C₅H₅NiPBu₃SC(O)NRH.Treatment of π-C₅H₅NiPBu₃SC(S)R with HCl gives π-C₅H₅NiSC(S)R.     

Tricyanmethanido-tris(pentahapto-cyclopentadienyl) Uran(IV): Polymere Uran-Organyle mit ungewöhnlicher Koordination am Uran(IV)

Tricyanmethanide-tris(h⁵-cyclopentadienyl)uranium (IV): Polymeric Organouranium Systems with an Unusual Coordination of the Uranium (IV)Ion (h⁵-C₅H₅)₃UCl viz. (h⁵-C₅H₄CH₃)₃UCl react in H₂O or THF with K[C(CN)₃] to give in good yields the new complexes (h⁵-C₅H₅)₃U[C(CN)₃] and (h⁵-C₅H₄CH₃)₃U[C(CN)₃] which turn out surprisingly stable relative to the organometallic starting material. The chemical and spectroscopic properties (IR, NIR/VIS and ¹H-NMR spectra) indicate the formation of extended oligomeric structures linked via C(CN)₃-bridges involving most probably linear sections: along with a trigonal planar arrangement of the three cyclopentadienyl ring normals.     

NMR Study of the Interaction of Tin(II) and Antimony(III) Fluorides with Phosphorus Chlorides

Reactions of SnF₂ and SbF₃ with POCl₃ and PCl₅ in acetonitrile were studied by ¹⁹F, ³¹P, and ¹¹⁹Sn NMR. Tetrahedral compounds POF₂Cl and POF₃ form in the reaction with POCl₃. Interaction of SnF₂ and SbF₃ with PCl₅ yields higher (in terms of fluorine) octahedral complexes [PF₅ · MeCN] and [PF₆]^–. In all cases, fluorine-free phosphorus compounds are found in the acetonitrile solution.