Synthesis and characterization of dinuclear p-, m- and o-xylyl bridged complexes of molybdenum and tungsten. The crystal structures of μ-p-xylyl- bis(η-pentamethyl-cyclopentadienyltri- carbonylmolybdenum) and μ-m-xylyl-bis(η- pentamethylcyclopentadienyltricarbonyltungsten)

The reactions of (M = Mo, W) with α,α′-p-, m- and o-dichloro-xylenes yielded p-, m- and o-xylyl bridged dinuclear complexes of in high yields. All of such new complexes are stable to air and water, even stable in dilute acids and bases.     

Synthesis and X-ray structural characterization of mono(aminophosphine) derivatives of molybdenum hexacarbonyl, Mo(CO)5L {L?=?P(NC5H10)3, P(Ph)(NC4H8O)2 or P(Ph){N(i-C3H7)2}(NC4H8O)}

Equimolar reactions of molybdenum hexacarbonyl with tris(piperidino)phosphine (L1), bis(morpholino)(phenyl)phosphine (L2), and (Di-isopropylamino)(morpholino)(phenyl) phosphine (L3), which are examples of symmetrically and unsymmetrically substituted tertiary(amino)phosphines, afford the corresponding mono derivatives, Mo[P(NC₅H₁₀)₃)](CO)₅ (1), Mo[P(Ph)(NC₄H₈O)₂](CO)₅ (2), and Mo[P(Ph){N(i-C₃H₇)₂}(NC₄H₈O)](CO)₅ (3) in moderate yields as air stable crystalline solids. In the case of L1, some amount of trans-bis derivative, Mo[P(NC₅H₁₀)₃)]₂(CO)₄ (4), was also isolated. X-ray structures of 1, 2, and 3 have been determined. Compounds 1 and 2 crystallize in the monoclinic system with space group P21/c, while 3 crystallizes in the triclinic system with space group Pī. While the Mo-P and Mo-C_ax bond distances in these complexes are comparable with those of other P-C bonded phosphines, the presence of chiral phosphine seems to induce a relatively weaker interaction with the molybdenum center. Intermolecular hydrogen bonding is seen in compound 1.     

Synthesis,characterization and crystal structure determination of iron(III) complexes containing 4,4′-dimethyl-2,2′-bipyridine,dimethyl sulfoxide and chloride, [Fe(dmbipy)Cl4][dmbipyH] and [Fe(dmbipy)Cl3(DMSO)]

[Fe(dmbipy)Cl₄][dmbipyH], 1 (dmbipy is 4,4′-dimethyl-2,2′-bipyridine), was prepared from reaction of FeCl₃ · 6H₂O with 4,4′-dimethyl-2,2′-bipyridine in 0.1 molar aqueous HCl. Treatment of 1 with dimethyl sulfoxide in methanol produced [Fe(dmbipy)Cl₃(DMSO)], 2 (DMSO is dimethyl sulfoxide). Both complexes were characterized by IR, UV-vis, and ¹H-NMR spectroscopies and their structures were studied by single crystal diffraction. Compounds 1 and 2 are high-spin with spin multiplicity of six.     

Synthesis and characterization of binuclear μ-oxo and μ-telluro molybdenum(V) complexes, [CpMo(O)(μ-Te)]2

Pyrolysis of an in-situ generated intermediate, produced in the reaction of [Cp^∗MoCl₄], 1, (Cp^∗ = η⁵-C₅Me₅) with [LiBH₄·THF], with an excess of difuryl ditelluride in toluene at 90 °C yielded syn and anti isomers of [Cp^∗Mo(O)(μ-Te)]₂ (2, 3) and [Cp^∗₂Mo₂O₂(μ-O)(μ-Te)] (4, 5). In a similar fashion, dibenzyl diselenide yielded syn and anti isomers of [Cp^∗Mo(O)(μ-Se)]₂ (6, 7), along with the known nido-[(Cp^∗Mo)₂B₄H₈Se₂]. Note that in parallel with 2-7, [(Cp^∗Mo)₂B₅H₉] was isolated as the major product in both cases. Compounds 2-7 have been isolated in modest yield as orange to brown crystalline solids. All the new compounds have been characterized in solution by mass, IR, ¹H, ¹³C, ⁷⁷Se and ¹²⁵Te NMR spectroscopy, and the structural types were unequivocally established by crystallographic analysis of 2-4 and 7.     

Syntheses and characterization of η-cyclopentadienyl and η-indenyl ruthenium(II) complexes of arylazoimidazoles: The molecular structure of the complex [(η-C5H5)Ru(PPh3)(C6H5-NN-C3H3N2)]

The complex [(η⁵-C₅H₅)Ru(PPh₃)₂Cl] (1) reacts with several arylazoimidazole (RaaiR′) ligands, viz., 2-(phenylazo)imidazole (Phai-H), 1-methyl-2-(phenylazo)imidazole (Phai-Me), 1-ethyl-2-(phenylazo)imidazole (Phai-Et), 2-(tolylazo)imidazole (Tai-H), 1-methyl-2-(tolylazo)imidazole (Tai-Me) and 1-ethyl-2-(tolylazo)imidazole (Tai-Et), gave complexes of the type [(η⁵-C₅H₅)Ru(PPh₃)(RaaiR′)]⁺ {where R, R′ = H (2), R = H, R′ = CH₃ (3), R = H, R′ = C₂H₅ (4), R = CH₃, R′ = H (5), R, R′ = CH₃ (6), R = CH₃, R′ = C₂H₅ (7)}. The complex [(η⁵-C₉H₇)Ru(PPh₃)₂(CH₃CN)]⁺ (8) undergoes reactions with a series of N,N-donor azo ligands in methanol yielding complexes of the type [(η⁵-C₉H₇) Ru(PPh₃)(RaaiR′)]⁺ {where R, R′ = H (9), R = H, R′ = CH₃ (10), R = CH₃, R′ = H (11), R = CH₃, R′ = C₂H₅ (12)}, respectively. These complexes were characterized by FT IR and FT NMR spectroscopy as well as by analytical data. The molecular structure of the complex [(η⁵-C₅H₅)Ru(PPh₃)(C₆H₅-NN-C₃H₃N₂)]⁺ (2) was established by single crystal X-ray diffraction study.     

Synthesis, characterization, and DNA binding of the biologically relevant novel cationic molybdenum(VI)–glutathione complex [Mo(GS)(Cl)(H2O)]Cl2

Abstract  

The complex [Mo(GS)(Cl)(H₂O)]Cl₂ (MoG) was synthesized in aqueous medium and its composition has been determined by elemental and thermogravimetric analysis. Binding modes were determined by ¹H NMR, ¹³C NMR, mass, and FT-IR spectrometry. The molecular formula was confirmed by mass spectral analysis. The molecular weight of the complex determined by the Rast camphor method also supports the formulation M _r = 525. This molecular formula demands the compound to be a 1:2 electrolyte, which is also supported by the conductance measurement, its value being 210 Ω⁻¹ cm². The compound is found to be diamagnetic, indicating that the molybdenum is in the +6 oxidation state (d⁰). The binding of MoG with calf thymus DNA was studied by spectroscopic titration. The interaction ratio was determined by monitoring the DNA 260 nm band as well as the S → Mo LMCT band of the complex observed at 225 nm. The interaction ratio calculated from the above studies was found to be 1:0.70 (DNA:MoG) in both cases, while the binding constant of DNA–MoG was found to be (4.8 ± 0.5) × 10⁵ M⁻¹. The binding constant data indicate that the binding nature is intercalative.     

Synthesis and reactivity of new mono- and dinuclear niobium and tantalum imido complexes: X-ray crystal structure of [Ta(η-C5H4SiMe3)Cl2{NC6Me4-4-(N(SiMe3)2)}]

The reaction of [1,4-{SiMe₃(H)N}₂C₆Me₄] (1) with 2 equivalents of LiBuⁿ followed by the addition of SiMe₃Cl gave the diamine compound [1,4-{(SiMe₃)₂N}₂C₆Me₄] (2). [Ta(η⁵-C₅H₄SiMe₃)Cl₄] reacts with 2, in a 2:1 stoichiometric ratio, to initially yield a mixture of the dinuclear, [{Ta(η⁵-C₅H₄SiMe₃)Cl₂}₂(μ-1,4-NC₆Me₄N)] (3), and mononuclear, [Ta(η⁵-C₅H₄SiMe₃)Cl₂{NC₆Me₄-4-(N(SiMe₃)₂)}] (4), imido complexes. 3 can be obtained exclusively by submitting the reaction mixture to repeated cycles of evacuation, to remove volatiles, followed by addition of solvent and subsequent heating. The mononuclear imido complex 4 was isolated from the reaction of [Ta(η⁵-C₅H₄SiMe₃)Cl₄] with 2 in a 1:1 stoichiometric ratio. The molecular structure of 4 was determined by X-ray diffraction studies. [TaCl₃(CH₃CN)₂{NC₆Me₄-4-(N(SiMe₃)₂)}] (5) has been prepared by the reaction of one molar equivalent of TaCl₅ with 2 in a CH₃CN/CH₂Cl₂ solvent mixture. The synthesis of the niobium complexes, [{Nb(η⁵-C₅H₄SiMe₃)Cl₂}₂(μ-1,4-NC₆Me₄N)] (6) and [Nb(η⁵-C₅H₄SiMe₃)Cl₂{NC₆Me₄-4-(N(SiMe₃)₂)}] (7), was achieved in a similar manner to their tantalum analogues. The reactivity of 7 towards nucleophilic reagents, namely lithium benzamidinate, lithium (trimethylsilyl)cyclopentadienyl or lithium dimethylamide, has been studied and the following compounds prepared:[Nb(η⁵-C₅H₄SiMe₃)RCl{NC₆Me₄-4-(N(SiMe₃)₂)}] (R = η⁵-C₅H₄SiMe₃ (8), PhC(NSiMe₃)₂ (9), NMe₂ (10)). In an attempt to form the hetero bimetallic complex, [{Nb(η⁵-C₅H₄SiMe₃)Cl₂}(μ-1,4-NC₆Me₄N){Ta(η⁵-C₅H₄SiMe₃)Cl₂}] (11), the reaction of 7 with [Ta(η⁵-C₅H₄SiMe₃)Cl₄] has been studied. Analysis of the reaction products showed that 11 may exist in equilibrium with the homo bimetallic complexes 3 and 6.     

Cyclopentadienyl chromium complexes with halide, methyl, isothiocyanate and isoselenocyanate ligands: Structures of [η-(C5H4-COOCH3)]Cr(NO)2(Br) and [η-(C5H4-COOCH3)]Cr(NO)2(NCS)

Bromination/nitrosylation of [η⁵-(carbomethoxy)cyclopentadienyl]dicarbonylnitrosylchromium (8) (hereafter called carbomethoxycynichrodene) with hydrogen bromide/isoamyl nitrite gives bromo [η⁵-(carboxymethoxy)cyclopentadienyl]dinitrosylchromium (10) in 84%. Compounds 15 in 74% and 16 in 90% were obtained from the corresponding cynichrodene derivatives via the same method. Compounds [η⁵-(carbomethoxy)cyclopentadienyl](isothiocyanato)dinitrosylchromium (13) and [η⁵-(carbomethoxy)cyclopentadienyl](isoselenocyanato)dinitrosylchromium (14) were prepared from [η⁵-(carbomethoxy)cyclopentadienyl]chlorodinitrosylchromium (9) with excess potassium thiocyanate and selenocyanate, respectively, after detaching the chloride by the action of silver nitrate. One of the nitrosyl groups in each compound is located at the site away from the exocyclic carbonyl carbon of the Cp(Cr) ring with twist angles of 168.5° and 172.3°, respectively. The chemical shifts of C(2)-C(5) carbon atoms of a series of substituted-cyclopentadienyldinitrosylchromium derivatives, [η⁵-(C₅H₄-sub)]Cr(NO)₂X, have been assigned using two-dimensional HetCOR NMR spectroscopy. The assigned chemical shifts were compared with the NMR data of their analogues of ferrocene, and the opposite correlation on the assignments was observed. The electron density distribution in the cyclopentadienyl ring is discussed on the basis of ¹³C NMR data and those of 10 and 13 are compared with the calculations via density functional B3LYP correlation-exchange method.     

Synthesis and crystal structure of π-complex of copper(I) with 1-allylbenzimidazolium cation [C7H5N2H(C3H5)]+ [Cu3Cl4]?

Single crystals of [C₇H₅N₂H(C₃H₅)]⁺[Cu₃Cl₄]^– were obtained for the first time by ac electrochemical synthesis from 1-allylbenzimidazolium and copper(II) chlorides in ethanol and structurally characterized. The unit cell parameters are a=8.6755(9) , b=8.846(1) , c=10.4540(7) , =85.36(1)°, =70.529(7)°, =83.29(1)° , V=750.5(3) ³, space group P , R(F)=0.0551. In the -complex, the copper and chlorine atoms form complicated infinite chains along the x axis. The 1-allylbenzimidazolium cation functions as an original bridge: it is coordinated by the Cu atom of one cuprous-chloride chain through the C=C bond of the allyl group and forms a N-HCl hydrogen bond with another inorganic chain through the N atom of the imidazole ring. The trigonal pyramidal environment of the Cu(1) atom includes three Cl atoms and the C=C bond; the environments of the Cu(2), Cu(3), and Cu(3a) are composed only of chlorine atoms. The positions of the Cu(2) and Cu(3a) atoms are partially disordered, which is manifested by the high thermal parameters for the Cu(2) atom and by the splitting of another copper atom into two equally occupied positions Cu(3) and Cu(3a).Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 3, 2005, pp. 199–203.Original Russian Text Copyright © 2005 by Goreshnik, Schollmeyer, Myskiv.This revised version was published online in April 2005 with a corrected cover date.This revised version was published online in April 2005 with a corrected cover date.     

Dimeric and polymeric copper(I) complexes. Synthesis and characterization of copper(I) complexes of di-2-pyridyl ketone oxime (DPKox) and crystal structures of [Cu(DPKox)Cl]2·2H2O and [Cu(DPKox)(NCS)]n

Copper(I) complexes with di-2-pyridylketone oxime (DPKox) of the type CuLX·nH₂O, n=1 for X=Cl and Br, and n=0 for X=I and SCN, have been synthesized and characterized. The overall physical results suggest tridentate and bidentate DPKox ligand in the Cl, Br and I, SCN complexes, respectively, and terminal X in the former but bridging X in the later. These complexes display MLCT bands in the visible region, but they do not fluoresce at room temperature. The structure determination has shown the chloride complex (1) to have a centro-symmetrically related dimeric unit, in which each copper atom is coordinated by Cl(1), N(1), N(2) and N(3) (of the second ligand molecule) in a distorted tetrahedral environment. Hydrogen bonds are formed by the O(1) of the oxime group and a lattice water molecule, and between different lattice water molecules and Cl(1). The structure of the thiocyanate complex (2) features tetrahedral geometry around copper atoms, a chelating bidentate DPKox ligand coordinating via one of the two pyridyl nitrogens, N(1), and N(oxime) only and μ-1,3-thiocyanate group forming zigzag chains along the c-axis of the unit cell.     

Synthesis and crystal structures of [UO2(C6H4NO2)2(C6H5NO2)] and [UO2SO4(C6H5NO2)(H2O)] · H2O

The complexes [UO₂(C₆H₄NO₂)₂(C₆H₅NO₂) (I) and [UO₂SO₄(C₆H₅NO₂)(H₂O)] · H₂O (II) were synthesized and studied by X-ray diffraction analysis. Crystals I are monoclinic: a = 7.0081(3), b = 14.9624(7), c = 9.1837(5) ?, β = 96.594(2)°, Z = 2, space group P2₁/m. Crystals II are triclinic: a = 6.8097(6), b = 9.3837(8), c = 10.4556(10) ?, α = 85.279(3), β = 75.434(3), γ = 69.180(3)°, Z = 2, space group . The main structural unit of crystal I is a mononuclear fragment, which belongs to the crystal chemical group AB ₂ ⁰¹ M¹ (A = UO ₂ ²⁺ , B⁰¹ are ions of pyridine-2-carboxylic (picolinic) acid, M¹ are molecules of picolinic acid) of the uranyl complexes. The main structural unit of crystal II is a chain, which belongs to the crystal chemical group AT³M ₂ ¹ (where T³-SO ₄ ²⁻ , M¹ are water and picolinic acid molecules) of the uranyl complexes. Picolinic acid in complexes I, II was found to have a zwitterion structure. Original Russian Text ? E.V. Grechishnikova, E.V. Peresypkina, A.V. Virovets, Yu.N. Mikhailov, L.B. Serezhkina, 2007, published in Koordinatsionnaya Khimiya, 2007, Vol. 33, No. 6, pp. 468–475.     

Synthesis,spectral characterization,and anticancer activity of 6-methylpyridine-2-carbaldehdyethiosemicarbazone and its complexes; crystal structure and DFT calculations of [Pd(mpyptsc)Cl]·DMSO

Synthesis and characterization of new complexes of 6-methylpyridine-2-carbaldehydethiosemicarbazone (Hmpytsc) and 6-methylpyridine-2-carbaldehyde-N(4)-phenylthiosemicarbazone (Hmpyptsc) with [VO₂L], [Zn(HL)Cl₂], [Ru(PPh₃)₂L₂], and [MLCl] (M(II)?=?Pd, Pt; HL?=?Hmpytsc, Hmpyptsc) are reported. Their structures are discussed on the basis of IR, Raman, UV–vis, NMR (¹H, ¹³C, and ³¹P), and mass spectroscopic data, as well as elemental analysis and molar conductivity. In the X-ray crystal structure of the square-planar [Pd(mpyptsc)Cl]·DMSO, mpyptsc^? is coordinated to Pd(II) in a tridentate manner through pyridyl N, azomethine N, and thiol S, and the fourth coordination site is occupied by a chloride. A theoretical study on [Pd(mpyptsc)Cl]·DMSO was undertaken through DFT conformational analysis. The in vitro cytotoxic activity has been evaluated against human colon cancer (HCT116) and prostate cancer (DU145) cell lines. Hmpyptsc and [Zn(Hmpyptsc)Cl₂] were most active with mean IC₅₀ values of 3.32 and 2.60 (HCT116), and 3.60 and 3.10 (DU145)?μM, respectively.     

Role of π-acceptor effects in controlling the lability of novel monofunctional Pt(II) and Pd(II) complexes: crystal structure of [Pt(tripyridinedimethane)Cl]Cl

The kinetics and mechanism of substitution reactions of novel monofunctional [Pt(tpdm)Cl](+) and [Pd(tpdm)Cl](+) complexes (where tpdm = tripyridinedimethane) and their aqua analogues with thiourea (tu), L-methionine (L-met), glutathione (GSH), and guanosine-5'-monophosphate (5'-GMP) were studied in 0.1 M NaClO(4) at pH = 2.5 (in the presence of 10 mM NaCl for reactions of the chlorido complexes). The reactivity of the investigated nucleophiles follows the order tu > l-met > GSH > 5'-GMP. The reported rate constants showed the higher reactivity of the Pd(II) complexes as well as the higher reactivity of the aqua complex than the corresponding chlorido complex. The negative values reported for the activation entropy as well as the activation volume confirmed an associative substitution mode. In addition, the molecular and crystal structure of [Pt(tpdm)Cl]Cl was determined by X-ray crystallography. The compound crystallizes in a monoclinic space group C2/c with two independent molecules of the complex and unit cell dimensions of a = 38.303(2) ?, b = 9.2555(5) ?, c = 27.586(2) ?, β = 133.573(1)°, and V = 7058.3(8) ?(3). The cationic complex [Pt(tpdm)Cl](+) exhibits square-planar coordination around the Pt(II) center. The lability of the [Pt(tpdm)Cl](+) complex is orders of magnitude lower than that of [Pt(terpyridine)Cl](+). Quantum chemical calculations were performed on the [Pt(tpdm)Cl](+) and [Pt(terpyridine)Cl](+) complexes and their reactions with thiourea. Theoretical computations for the corresponding Ni(II) complexes clearly demonstrated that π-back-bonding properties of the terpyridine chelate can account for acceleration of the nucleophilic substitution process as compared to the tpdm chelate, where introduction of two methylene groups prevents such an effective π-back bonding.     

Syntheses and crystal structures of nine-coordinate K2[EuIII(dtpa)(H2O)]·5H2O and Na2[TbIII(Httha)]·6H2O complexes

The title complexes, K₂[Eu^III(dtpa)(H₂O)]·5H₂O (H₅dtpa = diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid), Na₂[Tb^III(Httha)]·6H₂O (H₆ttha = triethylenetetramine-N,N,N′,N′,N″,N″-hexaacetic acid), were prepared, and their compositions and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques. The crystal of K₂[Eu^III(dtpa)(H₂O)]·5H₂O belongs to triclinic crystal system and $ P\bar 1 $ P\bar 1 space group. The crystal data are as follows: a = 8.3540(17), b = 10.147(2), c = 15.059(3) α = 84.63(3)?, β = 82.02(3)°, γ = 83.96(3)°, V = 1253.1(4)?³, Z = 2, R = 0.0325 and wR = 0.1013 for 4407 observed reflections with I ≥ 2σ(I). The [Eu^III(dtpa)(H₂O)]²⁻ has a nine-coordinate pseudo-monocapped square antiprismatic structure, in which the nine coordinate atoms, three N and six O are from one dtpa ligand and one water molecule. The crystal of the Na2[Tb^III(Httha)]·6H₂O belongs to monoclinic system and P2₁/c space group. The crystal data are as follows: a = 10.3976(10), b = 12.7908(13), c = 23.199(2) ? = 90.914(2)°, V = 3084.9(5)?³, Z = 4, R = 0.0309 and wR = 0.0704 for 5429 observed reflections with I ≥ 2σ(I). In the [Tb^III(Httha)]²⁻, the Tb³⁺ ion is nine-coordinated yielding a pseudo-monocapped square antiprismatic conformation, in which the ttha ligand coordinates to the central Tb³⁺ ion with four N atoms and five O atoms. There is a free non-coordinate carboxyl group (−CH₂COOH) that can be modified by some biological molecules having target function.     

Synthesis and reactions of cycloheptadienyl and cyclooctadienyl tungsten complexes: X-ray crystal structure of [W(CO)2(PPh3)2(η-C7H9)][BF4]

Protonation of the cycloheptatriene complex [W(CO)₃(η⁶-C₇H₈)] with H[BF₄] · Et₂O in CH₂Cl₂ affords the cycloheptadienyl system [W(CO)₃(η⁵-C₇H₉)][BF₄] (1). Complex 1 reacts with NaI to yield [WI(CO)₃(η⁵-C₇H₉)], which is a precursor to [W(CO)₂(NCMe)₃(η³-C₇H₉)][BF₄], albeit in very low yield. The dicarbonyl derivatives [W(CO)₂L₂(η⁵-C₇H₉)]⁺ (L₂=2PPh₃, 4, or dppm, 5) were obtained, respectively, by H[BF₄] · Et₂O protonation of [W(CO)₂(PPh₃)(η⁶-C₇H₈)] in the presence of PPh₃ and reaction of 1 with dppm. The X-ray crystal structure of 4 (as a 1/2 CH₂Cl₂ solvate) reveals that the two PPh₃ ligands are mutually trans and are located beneath the central dienyl carbon and the centre of the edge bridge. The first examples of cyclooctadienyl tungsten complexes [WBr(CO)₂(NCMe)₂(1-3-η:5,6-C₈H₁₁)] (6) and [WBr(CO)₂(NCMe)₂(1-3-η:4,5-C₈H₁₁)] (7) were synthesised by reaction of [W(CO)₃(NCR)₃] (R=Me or Prⁿ) with 3-Br-1,5-cod/6-Br-1,4-cod or 5-Br-1,3-cod/3-Br-1,4-cod (cod=cyclooctadiene), respectively. Complexes 6 and 7 are precursors to the pentahapto-bonded cyclooctadienyl tungsten species [W(CO)₂(dppm)(1-3:5,6-η-C₈H₁₁)][BF₄] and [W(CO)₂(dppe)(1-5-η-C₈H₁₁)][BF₄] · CH₂Cl₂.     

Synthesis and chemistry of tris(2-pyridyl)phosphine and bis(2-pyridyl)phenylphosphine complexes of mercury(II) X (X = Br,Cl) and X-ray crystal structural determination of [HgBr2(PPh(2-py)2)2]

Mercury(II) halide complexes [HgX₂(P(2-py)₃)₂] (X?=?Br (1), Cl (2)) and [HgX₂(PPh(2-py)₂)₂] (X?=?Br (3), Cl (4)) containing P(2-py)₃ and PPh(2-py)₂ ligands (P(2-py)₃ is tris(2-pyridyl)phosphine and PPh(2-py)₂ is bis(2-pyridyl)phenylphosphine) were synthesized in nearly quantitative yield by reaction of corresponding mercury(II) halide and appropriate ligands. The synthesized complexes are fully characterized by elemental analysis, melting point determination, IR, ¹H, and ³¹P-NMR spectroscopies. Furthermore, the crystal structure of [HgBr₂(PPh(2-py)₂)₂] determined by X-ray diffraction is also reported.     

Synthesis of homo- and heteronuclear ruthenium-gold clusters with diphosphine and thiolato bridged ligands. Single crystal molecular structure of [Ru3(CO)10(μ-AuPPh3)(μ-SC5H4N)] and [Ru3(CO)8(μ-H)(μ-SC5H4N)(μ-dppe)]

The reaction between [Ru₃(CO)₁₀(NCMe)₂] and [AuClPPh₃] gave compound [Ru₃(CO)₁₀(μ-Cl)(μ-AuPPh₃)] (1) in quantitative yield under very mild conditions. The reaction of 1 with 4-mercaptopyridine (4-pyS) using ultrasonic reaction conditions gave the heteronuclear compound [Ru₃(CO)₁₀(μ-AuPPh₃)(μ-SC₅H₄N)] (2) in moderate yield. There was no spectroscopic evidence that indicates the formation of the hydride isolobal analog in this reaction. The homonuclear cluster [Ru₃(CO)₈(μ-H)(μ-SC₅H₄N)(μ-dppe)] (3) was prepared by a selective reaction employing the ruthenium-diphosphine derivative [Ru₃(CO)₁₀(μ-dppe)] (dppe = 1,2-bis(diphenylphosphine)ethane) with 4-pyS in THF solution. The isolobal analog to compound 3, compound [Ru₃(CO)₈(μ-AuPPh₃)(μ-SC₅H₄N)(μ-dppe)] (4) was synthesized by the reaction between compound 2 and dppe in refluxing dichloromethane. Compounds 1-4 were characterized in solution by spectroscopic methods and the molecular structure of compounds 2 and 3 in the solid state was obtained by single crystal X-ray diffraction studies.     

Synthesis,crystal structures and spectral properties of cobalt (Ⅱ) complexes:[ CoL (N_3) ] ·ClO_4 and CoL (N_3)_2 [L=tris ((3,5-dimethylpyrazol-1-yl) methyl) amine

Two monomeric cobalt(Ⅱ)complexes,[CoL(N3)] ClO4(1)and CoL(N3)2(2),where L is tris((3,5-dimethylpyrazol-1-yl)methyl)amine,were synthesized and their crystal structures were determined by X-ray diffraction technique.Complex 1 is five coordinated with one azide nitrogen atom and four nitrogen atoms of the tris((3,5-dimethylpyrazol-l-yl)-methyl)amine ligand,and the metal center is in distorted trigonal bipyramidal environment.Complex 2 is six coordinated distorted octahedron with the two azide nitrogen atoms and four nitrogen donors of the tris((3,5-dimethylpyrazol-1-yl)-methyl)amine ligand.The solution behaviors of the title complexes have been further investigated by UV-Vis,and 1H NMR analysis.It is found that the formation of 1 and 2 depends on the molar ratio of the azide ion to metal salt and ligand Complex 1 attached with one azide group is more stable and easy to generate than complex 2 incorporated with two azide groups,and the reasons were well discussed.     

Synthesis,crystal structures and characterization of iron(III) and cobalt(III) complexes bearing 2,2′-bipyridylcarboxylate ligands

Transition Metal Chemistry - The Fe(III) complex [FeIII(bpdc)(Hbpdc)] (1) (bpdc?=?2,2′-bipyridyl-6,6′-dicarboxylate and...