Tungsten(V) dimeric complexes with heterocyclic dithiocarbamates

In this paper we report the syntheses and study of a number of oxo- and sulphido-bridged tungsten(V) complexes with morpholine dithiocarbamate and piperidine dithiocarbamate as ligands. We assign the following formulae to the complexes: W₂O₃(Rdtc)₄, W₂O₄(Rdtc)₂, W₂O₂S₂(Rdtc)₂ and W₂O₃S(Rdtc)₂ (where R = morpholine and piperidine), based on the analytical data. We have studied the complexes by IR and electronic spectra, and magnetic susceptibility measurements. We assign in the IR spectra the following bands: W=O (ν_s=939–948 cm^?1), W-O_b(ν_a=813–819 cm^?1, ν_s = 431–448 cm^?1), W-S_b (ν_a=470–476 cm^?1, ν_s = 368–370 cm^?1, C-N (β = 1511–1519 cm^?1) and C-S (ν = 1090–1113 cm^?1). The low values of the magnetic moments (0.03–0.60 B.M.) are in accordance with a dimeric species of tungsten(V).     

Preparation,characterization and cyclic voltammetric behaviour of dimeric sulphidomolybdenum(V) dithiocarbamate complexes

Mo₂S₄(R₂dtc)₂ (R = methyl, ethyl or benzyl; R₂ = pyrrolidinyl, piperidinyl or 4-morpholinyl) have been prepared starting from ammon     

Molybdenum(V) dimeric complexes with dialkyl carbamates

Syntheses are reported for a number of novel oxo and sulphido bridged molybdenum(V) complexes with N-methyl-N-cyclohexyl carbamate and N,N-dicyclohexyl carbamate as ligands, and we have compared these complexes with the molybdenum(V) complexes with dialkyldithiocarbamates as ligands. These complexes were identified by IR and electronic spectra, magnetic susceptibility and analytical data, and were assigned the formulae [Mo₂O₃(LL)₄], [Mo₂O₄(LL)₂], [Mo₂O₂S₂(LL)₂] and [Mo₂O₃S(LL)₂]. IR and electronic spectra of these compounds are sensitive to substitution of sulphur atoms into the bridge system. It is suggested that the low magnetic moments observed are due, at least in part, to intramolecular metal-metal interactions.     

Binuclear tungsten(V) oxo-complexes with 1,1-dithiolate ligands

In this paper we report the synthesis of some new oxo and sulphido bridged tungsten(V) complexes with N-ethylanilindithiocarbamate and N,N-methylcyclohexyldithiocarbamate as ligands. These complexes have been characterised by analytical, magnetochemical and spectral methods. The results permit us to assign the formulate: W₂O₃(LL)₄, W₂O₄(LL)₂, W₂O₂S₂(LL)₂ and W₂O₃S(LL)₂. The low magnetic moments observed in these complexes, are due either to an interaction through the bridging atoms or to a direct spin-spin interaction. IR and electronic absorption spectra of these complexes are sensitive to substitution of sulphur atoms into the bridge system. The systematic changes upon bridge modification are useful in characterizing the compounds and in clarifying assignments of W-O and W-S bridge stretching frequencies. The results are discussed on the basis of structural information available for tungsten complexes.     

Synthesis and characterization of triorganoantimony(V) complexes with bidentate ligands

Monochelated organoantimony(V) complexes of the type R₃Sb(OMe)L, where R = Me or Ph, and L is the anion of acetylacetone, 8-hydroxyquinoline, salicylaldehyde, o-hydroxyacetophenone or 2-hydroxy-1-naphthaldehyde have been obtained from triorganoantimony(V) dibromide and the sodium derivative of the ligands in a benzene-methanol mixture. Molecular weight determination in benzene reveals the monomeric nature of these complexes. IR and NMR data suggest that L acts as a bidentate ligand giving an octahedral environment for the antimony atom.     

New chemical reactivity in aromatic dithiocarbamate and monothiocarbamate ligands: syntheses of Mo2L4·2THF (L = Pyrrole or indole monothiocarbamate or pyrrole dithiocarbamate) and Mo2L4 (L = indoline monothiocarbamate)

The reactions between Mo₂(C₂H₃O₂)₄ and several new dithio- and monothiocarbamates have been studied. The first example of a dimolybdenum compound of a dithiocarbamate with the “molybdenum acetate” structure is reported (Mo₂L₄·2THF; L = pyrrole dithiocarbamate). In addition, the synthesis of Mo₂L′₄·2THF (L′ = pyrrole monothiocarbamate, indole monothiocarbamate, indole dithiocarbamate) and Mo₂L″₄ (L″ = indoline monothiocarbamate) are reported. A discussion of the unique stabilization of the dithiocarbamate bridge by “aromatic” dithio- and monothiocarbamates is presented.     

Study of the complexes of Np(V) with organic ligands by solvent extraction with TTA and 1, 10-phenanthroline

Complex formation constants of Np(V) with 22 organic ligands, 7 hydroxycarboxylic acids, 4 dicarboxylic acids, 4 aminocarboxylic acids, 3 pyridinecarboxylic acids, 8-hydroxyquinoline-5-sulfonic acid, IDA, NTA and EDTA, have been determined in 1M NaClO₄ at 25°C by using the solvent extraction method with TTA and 1, 10-phenanthroline. The factors influencing the stabilities of Np(V) complexes are discussed in connection with the linear structure of NpO₂⁺.     

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.     

Fluorinated barrelene-ruthenium(II) complexes with anionic chelating ligands

Reaction of ruthenium(III) chloride with the barrelene diolefins (tetrafluoro-benzobarrelene (TFB) or (trimethyltetrafluorobenzobarrelene) (Me₃ TFB) leads to the formation of the polymeric complexes [RuCl₂(barrelene)]_n. These compounds react with anionic chelating ligands with formation of new hexacoordinated neutral complexes of the general formulae [Rh(chelate)₂(barrelene)], where chelate = acetylacetonate, tropolonate, salicylal-dehydate and 8-oxyquinolinate. The IR and ¹H NMR spectra of the complexes are given and discussed.     

Palladium(II) malonato complexes with some heterocyclic ligands

Palladium(II) malonato complexes with heterocyclic ligands have been synthesized and characterized by spectroscopic and biological studies. The compoun     

Complex formation of peroxouranyl (and uranyl) with polyaminocarboxylate ligands

Complexation of the uranyl ion (UO₂²⁺) and of the peroxouranyl species (UO₄) by some polyaminocarboxylate ligands has been investigated in solution (3M NaClO₄) at 25°C. The logarithms of the cumulative formation constants of the UO₂²⁺ chelates formed are: UO₂edta^2? (15.65), UO₂Hedta^? (18.59), (UO₂)₂edta (20.24); UO₂edda (16.02); UO₂Hnta (12.19); UO₂ida (9.63), UO₂H₂(ida)₂ (23.80). The equilibrium UO₂²⁺ + H₂O₂ ? UO₄ + 2H⁺ has a stability log K = ?3.99. The peroxocomplexes formed are UO₄Hedda^? (14.81, expressed from UO₂²⁺ and H₂O₂) and UO₄Hnta^2? (8.50). Solution structures of the chelates are proposed.     

Dinitrogen complexes of iron(II) with chelating agents as ligands

Two new dinitrogen compounds of formulae Na₂[Fe(EDTA)N₂].2H₂O and Na₂[Fe(CDTA)N₂].2H₂O have been synthesized from [Fe(H-EDTA)H₂O] and [Fe(H-CDTA)-H₂O], respectively, and NaN₃. Both complexes have been characterized by IR and electronic spectra. The thermal behaviour has been studied by TG and DTA techniques.     

Alkyl complexes of palladium(II) with trimethylphosphine and 1,2-bis-(dimethylphosphino)ethane ligands

A number of neutral, mononuclear dialkylpalladium(II) tertiary phosphine complexes of geneal formula cis or trans-PdR₂(PMe₃)₂ and cis-PdR₂ (dmpe) [dmpe = 1,2-bis(dimethylphosphino)ethane], R = Me, CH₂Ph, CH₂CMe₂Ph, CH₂SiMe₃ have been obtained by interaction of magnesium reagents with palladium(II) acetate or trans-Pd(O₂CMe)₂(PMe₃)₂.     

Isolation of dithiocarbamate anions as salts of biscyclopentadienyl titanium(IV) chelates

A series of [Cp₂TiL]⁺[RR′NCS₂]^? complexes, where L is the conjugate base of acetylacetone, benzoylacetone or 8-hydroxyquinoline and R = CH₃, R′ = C₆H₅CH₂; R = C₂H₅, R′ = C₆H₄CH₃; R = H, R′ = C₅H₉; RR′ = C₆H₁₂, have been synthesised in aqueous medium by the reaction of [Cp₂TiL]⁺Cl^? with RR′NCS^?₂Na⁺. Conductivity measurements in nitrobenzene solution indicate that these complexes are electrolytes. Both the IR and NMR studies demonstrate that the ligand L is chelating in all these complexes. Consequently, tetrahedral coordination about the titanium atom is proposed. In addition to these studies, elemental analyses and magnetic susceptibility have been carried out for these complexes.     

Ruthenium(II) complexes with triphenylphosphine or triphenylarsine and other monodentate ligands

Synthesis and studies on some five-coordinate ruthenium(II) complexes, viz. [Ru(MPh₃)(C₆H₅CHO)₂Cl₂] and [Ru(MPh₃)₂(CO)Cl₂] (where M = P or As) have been described. Reactions of [Ru(MPh3)(C₆H₅CHO)₂Cl₂] with N,N-dimethylformamide, dimethylsulphoxide and pyridine and of [Ru(MPh₃)₂(CO)Cl₂] with pyridine are described.     

Synthesis and reactions of phenylimidotrimethyl-bis(trimethylphosphine)-rhenium(V). Synthesis and X-ray crystal structure of bis(trimethylsilylmethyl)oxo-rhenium(V)-μ-oxo-tetrakis(trimethylphosphine)rhenium (I)-(trimethylsilylmethyl)dioxorhenium(V), (ReRe)

The interaction of phenylimidotrichloro bis(trimethylphosphine) with dimethylmagnesium gives the trimethyl compound, Re(NPh)Me₃(PMe₃)₂. Exchange reactions between the trichloro and trimethyl compounds are studied by ¹H nuclear magnetic resonance and the intermediates Re(NPh)Me₂Cl(PMe₃)₂ and Re(NPh)MeCl₂(PMe₃)₂ isolated.The trimethyl reacts with fluoroboric acid to give a phenylamido complex [Re(NHPh)Me₂F(PMe₃)₂]BF₄, with acetic acid to give Re(NPh)Me(CO₂Me₃)₂, and with trityltetrafluoroborate to give [Re(NPh)Me₂(PMe₃)₂]BF₄.The interaction of Re(NPh)Cl₃(PMe₃)₂ with excess of bis(trimethylsilylmethyl)magnesium and of trimethyl-phosphine in tetrahydrofuran gives an unusual tri-rhenium compound, (Me₃SiCH₂)₃(O)Re-μ-O-Re(PMe₃)₄Re(O)₂(CH₂SiMe₃) whose structure as a thf solvate, has been determined by X-ray crystallography. Crystals of the latter are monoclinic, space group P2₁/n with a = 15.512(3), b = 15.392(2), c = 21.506(4) Å, β = 100.19(2)°, Z = 4. The structure has been refined to an R of 0.07 for 5028 observed diffractometer data. The molecule is tri-nuclear with the central rhenium carrying four PMe₃ groups being bound to the second rhenium by a short ReRe bond and to the third by an asymmetric oxygen bridge. The end rhenium bound to the bridge oxygen carries two CH₂SiMe₃ groups and an oxygen atom, while the other has one CH₂SiMe₃ group and two oxygen atoms.     

The reactions of some organotin(IV) chlorides with antimony(V) chloride and boron(III) chloride

The reactions of the organotin chlorides R_nSnCl_4?n(R = Me or Ph; ? n ? 4) with the Lewis acids SbCl₅ and BCl₃ have been investigated by ¹¹⁹Sn and (where appropriate) ¹¹B NMR spectroscopy. The results show that transfer of organo-groups to antimony or boron usually takes place rather than chloride abstraction to give cationic tin(IV) species, and this process is more facile for phenyl than methyl groups. These conclusions have been confirmed in some instances by isolation of the non-volatile reaction products.     

Rhodium(I) and rhodium(III) arene complexes with N-carbazolyltriphenylphosphinegold(I) and other polycyclic arene ligands

The new heteronuclear arene complexes [(COD)Rh(μ-cbz)AuPPh₃]ClO₄, [{(COD)Rh}₂(μ-cbz)AuPPh₃](ClO₄)₂, [(C₅Me₅)Rh(μ-cbz)AuPPh₃](ClO₄)₂ and [{C₅Me₅) Rh}₂(μ-cbz)AuPPh₃](ClO₄)₄ (COD = 1,5-cyclooctadiene, cbz = carbazolyl), and the mononuclear arene complexes [(COD)Rh(arene)]ClO₄ (arene = tetralin, biphenyl, fluorene, indene, 9,10-dihydroanthracene or carbazole) have been prepared by reaction of the acetone solvated complexes [(COD)Rh(Me₂CO)_x]ClO₄ or [(C₅Me₅)Rh(Me₂CO)₃](ClO₄)₂ with (cbz)AuPPh₃ or the appropriate polycyclic arene ligand.     

Structure of a diruthenium(II,III) complex with benzamidato bridging ligands

The compound Ru₂Cl(C₆H₅CONH)₄ has now been obtained in crystalline form and the crystal and molecular structure determined by X-ray met     

Fluorooxoperoxo complexes of vanadium(V)

Substances crystallizing under various conditions from the MVO₃(MF, HF)H₂O₂H₂O (M = NH₄, K) systems have been characterized by elemental analysis, infrared and Raman spectra and X-ray powder patterns. Besides the known M₂[VO(O₂)₂F] complexes, complexes of two new types have been obtained: M₃[HV₂O₂(O₂)₃F₄·2H₂O and (NH₄)₃[V₂O₂(O₂)₄F]·nH₂O (n≈2). Vibrational spectra of new complexes are consistent with the presence of dimeric anions containing V(μ₂O₂)V and VFV bridges, respectively.