Polynuclear rhodium complexes of phenothiazines: synthesis and characterization

Polynuclear complexes of RH^II and RH^III with fiveN-alkylphenothiazines as principal ligands have been prepared. The complexes were characterized by their elemental analyses, molar conductivities, and spectral data. The molecular formulae of the new complexes are as follows: [Rh₃(PTZ)₂(OH₂)₂Cl₈]Cl, where PTZ=chlorpromazine or promethazine; [Rh₃(EP)₂(OH₂)₂Cl₈][Rh(OH₂)₂Cl₄], where EP=ethopropazine; [Rh₄(TF)₂(OH₂)₅Cl₉]Cl·H₂O, where TF=trifluoperazine; and [Rh₂(TC)₃(OH₂)Cl₆]. H₂O, where TC=2-chlorophenothiazine. A tentative structure for each of the complexes is proposed. TMC 2627     

Synthesis and characterization of rhenium(VII) oxide complexes of phenothiazines

Summary Five complexes of rhenium(VII) oxide with N-alkylphenothiazines have been synthesized and characterized on the basis of elemental analyses, molar conductances, and u.v.-vis., i.r. and n.m.r. spectral data. The molecular formulas of the new ionic complexes are: [ReO₃(PTZ)₂(H₂O)][ReO₄], PTZ = chlorpromazine, promethazine or ethopropazine; [ReO₃(TF)(H₂O)][ReO₄], TF = trifluoperazine; and [ReO₃(TR)₃][ReO₄(H₂O)₂]·H₂O, TR = thioridazine. Tentative structures have been proposed.     

Binuclear molybdenum(V) complexes with morpholin carbamate

Summary Novel oxo-and sulphido-bridged molybdenum(V) complexes with morpholin carbamate as ligand, have been prepared, identified by i.r., electronic spectra, magnetic susceptibility and analytical data and assigned the formulae [Mo₂O₃(LL)₄], [Mo₂O₄(LL)₂], [Mo₂O₂S₂(LL)₂] and [Mo₂O₃S(LL)₂]. The spectra are modified by introduction of sulphur atoms into the bridge system. The low magnetic moments are thought be due, at least in part, to intramolecular metal-metal interactions. A comparison of the spectra of these complexes with those of analogous morpholin dithiocarbamate compounds has been made.     

Synthesis and characterization of iridium chloride complexes: I. Use of N-alkylphenothiazine drugs as ligands

Summary Iridium complexes of N-alkylphenothiazines have been prepared in MeOH. The polynuclear complexes obtained have been characterized by elemental analyses, magnetic susceptibilities, molar conductivities, thermogravimetric analysis and spectral data. The molecular formulae of the new complexes are as follows: [Ir₃(LH)₄Cl₁₀]Cl₂·xMeOH, where L = chlorpromazine (CP), promethazine (PM) or ethopropazine (EP), and x = 1 for CP and 2 for PM or EP; [Ir(TFH₂)₂Cl₄][IrCl₆]·MeOH, where TF = trifluoperazine; and [Ir₂(TRH)₂Cl₁₁(MeOH)]Cl·MeOH and [Ir₄(TRH)₃Cl₁₅], where TR = thioridazine. The complexes are diamagnetic in nature. Tentative structures are proposed for the complexes.     

Molybdenum(VI) and molybdenum(V) mononuclear and dinuclear complexes with 1,3-diphenyl-1,3-propanedione

Summary The synthesis and the dinuclear or mononuclear nature of several molybdenum(VI) and molybdenum(V) oxocomplexes derived from 1,3-diphenyl-1,3-propanedione (HLL) are described. These complexes were identified by i.r. and electronic spectra, magnetic susceptibility and analytical data, and are assigned the following formulae: [MoO₂(LL)₂], [Mo₂O₅(LL)₂], [Mo₂O₄(LL)₂], [MoOCl(LL)₂], [MoCl₂(LL)] and [MoO(OH)(LL)₂)]. The low magnetic moments of the dinuclear complexes are due, in part, to intramolecular interactions. The i.r. data show that the dionate is bound by two oxygen atoms forming a chelate six-membered ring.     

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.     

Potassium,rubidium and ammonium salts of μ‐(formato‐κ2O:O′)‐μ‐oxido‐bis[oxidobis(peroxido‐κ2O,O′)molybdate(VI)]

The unit‐cell parameters of the three title salts, namely, tripotassium, K₃[Mo₂(CHO₂)O₃(O₂)₄], trirubidium, Rb₃[Mo₂(CHO₂)O₃(O₂)₄], and triammonium μ‐(formato‐κ²O:O′)‐μ‐oxido‐bis[oxidobis(peroxido‐κ²O,O′)molybdate(VI)], (NH₄)₃[Mo₂(CHO₂)O₃(O₂)₄], which were all crystallized at pH 3, are quite similar, but the potassium and rubidium salt structures are noncentrosymmetric, whereas that of the ammonium salt is centrosymmetric. Formate acts as an O:O′‐bridging ligand in the complex anion and is bound to a μ‐oxido‐bis(oxidodiperoxidomolybdate) unit.     

Synthesis,characterization and anticancer activity of 3-aminopyrazine-2-carboxylic acid transition metal complexes

Synthetic procedures are described that allow access to the new complexes cis-[Mo₂O₅(apc)₂], cis-[WO₂(apc)₂], trans-[UO₂(apc)₂], [Ru(apc)₂(H₂O)₂], [Ru(PPh₃)₂(apc)₂], [Rh(apc)₃], [Rh(PPh₃)₂(apc)₂]ClO₄, [M(apc)₂], [M(PPh₃)₂(apc)]Cl, [M(bpy)(apc)]Cl (M(II) = Pd, Pt), [Pd(bpy)(apc)Cl], [Ag(apc)(H₂O)₂] and [Ir(bpy)(Hapc)₂]Cl₃, where Hapc, is 3-aminopyrazine-2-carboxylic acid. These complexes were characterized by physico-chemical and spectroscopic techniques. Both Hapc and several of its complexes display significant anticancer activity against Ehrlich ascites tumour cells (EAC) in albino mice.     

Structural studies of new group 6 complexes of salicylidene-2-aminopyridine

Interaction of salicylidene-2-aminopyridine (Hsap) with [M(CO)₆], M = Cr, Mo and W, in THF under sunlight resulted in formation of dinuclear complexes [Cr₂O₄(sap)], 1, [Mo₂O₄(sap)], 2, and [W₂O₅(sap)₂], 3. Elemental analysis, spectroscopic and magnetic studies of the reported complexes revealed the proposed structures. Magnetic studies of 1 and 2 suggested that the two metal centers have +3 and +6 formal oxidation states, while the tungsten complex 3 has +6 formal oxidation state with d⁰ electron configuration. The thermal properties of the complexes were investigated by thermogravimetry.     

[Mo4O4(μ-S)4(μ-OH)2(μ-H2O)(H2O)2(pba)]2−: An Original Coordination Mode for the Ligand 1,3-Propylenebis(Oxamate)

The novel polyoxothioanion [Mo₄S₄O₄(OH)₂(OH₂)₃pba]^2? where pba^4? ligand is the 1,3-propylenebis(oxamate), was prepared by reacting Mo₁₂S₁₂O₁₂(OH)₁₂(OH₂)₆ ring with [Cu-pba]^2? in aqueous medium. NaK[Mo₄O₄(μ-S)₄(μ-OH)₂(μ-H₂O)(H₂O)₂(pba)] ·7H₂O was isolated in the solid state and fully characterized by X-ray diffraction study (tetragonal, P4(2)/m [a=20.4962(4) Å; b=20.4962(4) Å; c=14.7013(5) Å). The molecular structure consists of an arc cycle shape tetranuclear enchainment {Mo₄S₄O₄(OH)₂ (OH₂)₃} closed by a pba^4? ligand. The 3-D packing, resulting from the connection between K⁺ and Na⁺ and the coordination complex {Mo₄-pba]^2? is described. The ¹H-NMR characterization of the complex in aqueous solution is given. The ¹H-NMR spectrum exhibits four signals assigned to four enantiotopic protons of the alkyl chain of the pba^4? ligand and is in agreement with crystal structure of the complex [Mo₄-pba]^2?. The compound was also characterized by infrared spectroscopy.     

The thiocyanato adduct of chromium(II) acetate

The first dichromium complex with axially bonded anions, [NEt₄]₂[Cr₂(O₂CCH₃)₄(NCS)₂], was obtained by reactions of [NEt₄]NCS with [Cr₂(O₂CCH₃)₄(OH₂)₂] in ethanol.     

Preparation of sodium dimolybdate by the pyrolysis of sodium oxomolybdenum (VI) oxalate

Thermal studies on various oxalato complexes have been of immense interest as they yield finely divided, highly reactive oxides which are usually obtained at a much lower temperature than that required in the conventional method of preparation, i.e., heating a mixture of two or more constituents [1]. A survey of the literature reveals that the compounds having the general formula A₂[Mo₂O₅(C₂O₄)₂(H₂O)₂], where A = K⁺, NH⁺₄[2] and A = Cs⁺ [3], have been prepared and their thermal decomposition is studied, but no such information is available regarding the preparation and characterisation of Na₂[Mo₂O₅(C₂O₄)₂(H₂O)₂] (SMO), which forms the subject of study of this paper. Sodium dimolybdate (Na₂Mo₂O₇), the decomposition product of SMO, is obtained at 280°C, a temperature much lower than that required in the conventional method of preparation of heating a mixture of Na₂MoO₄ and MoO₃ [4].     

2,4′-Bipyridyl complexes with cobalt(II) and nickel(II)

Summary Complexes of empirical formulae [ML₂Cl₂(OH₂)₂], [CoL₂Br₂(OH₂)₂]L·4H₂O, [NiL₂Br₂(OH₂)₂]L₂·2H₂O, [ML₂(OH₂)₄]L₂(NO₃)₂ and [ML₄(OH₂)₂](ClO₄)₂·2H₂O (M = Co^II, Ni^II, L = 2,4-bipyridyl) were synthesized and characterized by elemental and spectral analyses. The thermal decomposition of the complexes was also investigated.Author to whom all correspondence should be directed.     

Preparation,characterization and catalytic oxidation properties of bis‐quaternary ammonium peroxotungstates and peroxomolybdates complexes

Several novel kinds of bis‐quaternary ammonium peroxotungstates and peroxomolybdates, such as PhCH₂N(CH₂CH₂)₃NCH₂Ph[W₂O₃(O₂)₄], PhCH₂N(CH₂CH₂)₃NCH₂Ph [Mo₂O₃(O₂)₄], [PhCH₂(CH₃)₂NCH₂]₂[W₂O₃(O₂)₄] and [PhCH₂(CH₃)₂NCH₂]₂[Mo₂O₃(O₂)₄], have been synthesized and characterized by elemental analysis, IR and Raman spectroscopy. Their catalytic properties in mild oxidation of benzyl alcohol and ring‐substituted benzyl alcohols were investigated with aqueous 30% H₂O₂ under halide‐ and organic solvent‐free conditions. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis,characterization and antineoplastic activity of 5-chloro-2,3-dihydroxypyridine transition metal complexes

Synthetic procedures are described that allow access to cis-[Mo₂O₅(cdhp)₂]^2?, cis-[W₂O₅(Hcdhp)₂], trans-[OsO₂(cdhp)₂]^2?, trans-[UO₂(Hcdhp)₂], [ReO(PPh₃)(Hcdhp)₂]X (X =?Cl, I), [ReO₂(cdhp)₂]^?, [M(PPh₃)₂(cdhp)], [M(bpy)(cdhp)] (M(II) =?Pd, Pt), [Ru(YPh₃)₂(Hcdhp)₂] (Y =?P, As), [Rh(Hcdhp)₂Cl(H₂O)], [Rh(PPh₃)₂(Hcdhp)₂]ClO₄ and [Ir(bpy)(cdhp)Cl₂], where Hcdhp, cdhp are the deprotonated monoanion of 5-chloro-3-hydroxypyrid-2-one and dianion of 5-chloro-2,3-dihydroxypyridine, respectively. These complexes were characterized by their Raman, IR, ¹H NMR, electronic and mass spectra, conductivity, magnetic and thermal measurements. H₂cdhp, cis-K₂[Mo₂O₅(cdhp)₂], [Pd(bpy)(cdhp)] display a significant antineoplastic activity against Ehrlich ascites tumor cells (EAC).     

Di‐μ‐methoxy‐bis[(η5‐cyclopentadienyl)(nitrosyl‐κN)(trimethylsilylmethyl)molybdenum(II)]

The title complex, [Mo₂(C₅H₅)₂(CH₃O)₂(C₄H₁₁Si)₂(NO)₂], is formed in high yield by treating [CpMo(NO)(CH₂SiMe₃)₂] (Cp is cyclo­penta­dienyl) with methanol. The nitro­syl ligands are nearly linear [O—N—Mo 170.1 (4) and 170.1 (5)°], with short Mo—N bonds [1.769 (4) and 1.776 (4) Å] and long N—O bonds [1.216 (5) and 1.201 (4) Å]. The central four‐membered Mo₂O₂ ring exhibits an average Mo—O bond length of 2.15 Å.     

Structural Study and Solution Integrity of Dioxomolybdenum(VI) Complexes with Tridentate Schiff Base and Azole Ligands

Four new molybdenum complexes [Mo^VIO₂(L¹)(Him)] ( 1 ), [Mo^VIO₂(L¹)(3‐MepzH] ( 2 ), [Mo^VIO₂(L²)(3‐MepzH)] ( 3 ), and [(Mo^VIO₂)₂(μ‐L³)(MeOH)₂] ( 4 ) were synthesized and characterized by IR, NMR, ESI‐MS, and single‐crystal structure analysis [H₂L¹ = 2‐(salicylideneamino)‐2‐methyl‐1‐propanol, H₂L² = 2‐(3‐methoxysalicylideneamino)‐2‐methyl‐1‐propanol, H₄L³ = 1, 7‐bis(salicylidene)dihydrazide malonic acid, Him = imidazole and 3‐MepzH = 3‐methylpyrazole]. In all four structures the molybdenum atom has a distorted octahedral coordination with the three meridional donor atoms from the Schiff base di‐ or tetraanion (L^{1, 2})^2—/(L³)^4— and one oxo group occupying the sites of the equatorial plane. The other oxo group and the azole or methanol molecule occupy the apical sites. In 1—3 two centrosymmetrically related molecules form a hydrogen‐bonded pair through the (azole)N‐H···O(alkoxo) interaction. Additional crystal packing appears to be controlled mostly by π stacking between the aromatic rings of the salicyl moiety. ESI‐MS investigations reveal that the integrity of complexes 1—4 is largely retained in methanol solution. At the same time evidence is provided that di‐ to tetranuclear oligomers of formula [{Mo^VIO₂(L)}_x] and [{Mo^VIO₂(L)}_x(3‐MepzH)] with L = L¹, L², x = 2, 3, 4 are present simultaneously with 2 and 3 in methanol solution, respectively the tetranuclear species [{(Mo^VIO₂)₂(L³)}₂] with 4 .     

Urate complexes of dipositive first row transition metal ions

Summary The following complexes were prepared by reacting uric acid (uaH₂) with 3d metal(II) perchlorates in non-aqueous media: trans-[Mn(uaH)₂(OH₂)₄], octahedral, and [Co-(uaH)₂(OH₂)₂] tetrahedral, both involving O(8)-bound hydrogenurate; [Cu(ua)(OH₂)₃], tetrahedral, with the urate dianion binding via a ring nitrogen; and [Ni₂(uaH)₂-(uaH₂)(ClO₄)₂(H₂O)₃] formulated as a pentacoordinated linear polymetric species, involving bidentate bridging hydrogenurate, binding through O(8) and a ring nitrogen.Presented in part at the 4th Chemical Congress of North America (Ref. 1).     

4′-(2-Methylphenyl)-2,2′:6′,2″-terpyridine: coordination chemistry with Ni(II), Cu(II), Zn(II) and Ag(I)

The synthesis of 4′-(2-methylphenyl)-2,2′:6′,2″-terpyridine (L) has been improved. The coordination chemistry of the ligand was explored using Ni(II), Cu(II), Zn(II), and Ag(I) ions. X-ray crystallography, elemental analysis, NMR, and mass spectrometry were used to characterize the 13 new compounds that have been synthesized. Under different reaction conditions, Ni(II), Cu(II), and Zn(II) produced discrete complexes, sometimes containing more than one metal ion, while Ag(I) furnished a polymeric spiral complex in which the central pyridine nitrogen of each terpyridine ligand bridges two Ag(I) ions. Crystallographically characterized complexes are [Ni(L)₂]Cl₂, [Ni₂Cl₄(L)₂], [Ni(L)(OH₂)₃]Cl₂, [Ni(L)₂]Br₂, [Cu(L)(OH₂)(OSO₃)], [Cu₃Cl₆(L)₂], [Cu(L)(OH)(OH₂)₂]PF₆, [Cu(L)₂](OTf)₂, [Cu(L)(OAc)₂], [Zn(L)(OAc)₂], [Zn(L)Cl₂], [Zn(L)₂](NO₃)₂, [{Ag₂(μ-L)₂(μ-NO₃)}_n](NO₃)_n.     

New NQR and electrochemical observations on a series of quadruply bonded dimolybdenum complexes of arsines

Summary New coordination complexes of the type Mo₂X₄(AsEt₃)₄ and Mo₂(O₂CCF₃)₄(AsR₃)₂ where X=Cl, Br, NCS and R= Et or Ph, have been prepared. These compounds, identified and characterized by their Raman, infrared, u.v.-visible, and1 H n.m.r. have been studied by⁷⁵As n.q.r. spectroscopy. In the case of the two fluoroacetate complexes, n.q.r. and other spectroscopic data indicate that the two arsenic ligands are weakly coordinated at the axial position of the Mo ₂ ⁴⁺ unit. Rotating-disk electrode polarography and voltammetry show that Mo₂Cl₄(AsEt₃)₄ and Mo₂Br₄(AsEt₃)₄ can be oxidized through a reversible transfer of a single electron while interestingly Mo₂(NCS)₄(AsEt₃)₄ exhibits a two-step oxidation which leads successively to a paramagnetic cation [Mo₂(NCS)₄(AsEt₃)₄]⁺ and to a diamagnetic one [Mo₂(NCS)₄(AsEt₃)₄]²⁺.On leave from: Departamento de Química Inorgánica, Facultad de Quimica, Universidad de Barcelona, Diagonal, 647 Barcelona, Spain.