Synthesis and structural characterization of a polar Os(II,III) complex,Os2(fhp)4Cl

The title compound was prepared by prolonged reaction of Os₂(CH₃COO)₄Cl₂ with Hfhp (Hfhp = 6-fluoro-2-hydroxypyridine) in refluxing toluene in the presence of LiCl. The product, Os₂(fhp)₄Cl (1), is a result of ligand displacement with a concomitant core reduction of Os₂⁶⁺ to Os₂⁵⁺. Crystals were grown by slow diffusion of hexane into a dichloromethane solution of 1. Crystallographic data are as follows: tetragonal crystal system, space group I4mm (No. 107), a = b = 11.000(3) Å, c = 13.142(2) Å, V= 1590(1) ų, Z = 2. The molecule possesses crystallographic 4mm symmetry, with the OsOs bonds lying along the four-fold axes. The four fhp ligands are arranged in a polar fashion around the diosmium core, blocking one axial site. The second axial position is occupied by a chloride ion. The principal distances in 1 are: Os(1)Os(2) = 2.341(1) Å, Os(1)N = 2.027(12) Å, Os(2)O = 2.014(5) Å, Os(2)Cl = 2.487(7) Å. The title compound was also investigated by several physical methods. The electrochemistry as determined by cyclic voltammetry revealed two processes: a reversible, one-electron reduction at E_ox = −0.63 V in dichloromethane and an irreversible oxidation at E_ox = +0.95 V in dichloromethane vs Ag-AgCl at room temperature. The electronic spectrum shows strong bands at 413 nm (ε = 4290 M⁻¹ cm⁻¹), 309 nm (ε = 23,560 M⁻¹ cm⁻¹) and at 294 nm (ε = 26,500 M⁻¹ cm⁻¹) as well as shoulders at 334 and 261 nm.     

Ruthenium(II) and iron(II) complexes of N-pyridyl substituted imidazolin-2-ylidenes

N-mesityl-N′-pyridyl-imidazolium chloride 1a and the corresponding bromide salt 1b have been deprotonated with NaH in THF giving the free N-heterocyclic carbene N-mesityl-N′-pyridyl-imidazolin-2-ylidene 2 in 80% yield (starting from 1a). Imidazolium salt 1a reacts with RuCl₃ · xH₂O to give a racemic mixture of dinuclear di-μ-chloro bridged ruthenium complexes [(κ²-2)₂Ru(μ-Cl)₂Ru(κ²-2)₂]²⁺ [3a]²⁺. The carbene carbon atoms as well as the halides are arranged in cis-positions to each other whereas the nitrogen atoms adopt a trans-configuration. The di-μ-bromo bridged derivative [(κ²-2)₂Ru(μ-Br)₂Ru(κ²-2)₂]²⁺ [3b]²⁺ was obtained from RuCl₃ · xH₂O and 1b. The bridging halide ligands can be removed by the reaction with silver or sodium salts of bidentate Lewis acids. Complex [3a]²⁺ reacts with silver pyridylcarboxylate to give a racemic mixture of the mononuclear complex [4]⁺. Reaction of [3a]²⁺ with the sodium salt of l-proline resulted in a diastereomeric mixture of complexes [5]⁺. The free N-heterocyclic carbene 2 reacts with [FeCl₂(PPh₃)₂] to give after anion exchange with NaBPh₄ cis/cis/trans coordinated [Fe(κ²-2)₂(MeCN)₂](BPh₄)₂ [6](BPh₄)₂. The molecular structures of [3b](PF₆)₂, [4]PF₆ and [6](BPh₄)₂ · H₂O are reported.     

Hexacoordinate triphenylantimony(V) complex with tridentate bis-(3,5-di-tert-butyl-phenolate-2-yl)-amine ligand: Synthesis,NMR and X-ray study

The oxidative addition reaction of 4,6-di-tert-butyl-N-(2-hydroxy-3,5-di-tert-butyl-phenyl)-o-iminobenzoquinone (IBQ) to triphenylantimony(III) proceeds with the migration of hydroxyl-proton to a nitrogen atom to form tridentate O,N,O′-coordinated bis-(3,5-di-tert-butyl-phenolate-2-yl)-amine ligand. In accordance with ¹H, ¹³C, DEPT NMR data, the new hexacoordinate complex [bis-(3,5-di-tert-butyl-phenolate-2-yl)-amine]triphenylantimony(V), [(AP-AP)H]SbPh₃ (1) in solution has a C_s symmetry plane leading to the equivalence of two O,N-chelate o-aminophenolato moieties. The molecular structure of 1 · acetone was studied by a single-crystal X-ray. Compound 1 was found to be air-stable both in solid and in solution. Its oxidation by PbO₂ leads to paramagnetic [4,6-di-tert-butyl-N-(3,5-di-tert-butyl-phenolate-2-yl)-o-iminobenzosemiquinolato]triphenylantimony(V), [(AP-ISQ)]SbPh₃ (2).     

Osmium dimethyl sulfoxide complexes: Synthesis and properties of [H(dmso)2][OsIII(dmso)2Br4]

The reaction of H₂[OsBr₆] with DMSO in ethanol solution resulted in DMSO complex [H(dmso-O)₂][Os^III(dmso-S)₂Br₄] (1) described previously as an intermediate product in the reaction of K₂[OsBr₆] with DMSO and characterized by EAS and ESR spectra. The coordination of DMSO molecules was established by IR and ¹H and ¹³C NMR spectroscopy. The oxidation state of osmium and trans arrangement of DMSO molecules in the anion were established by ESR. The behavior of complex 1 in solutions was studied by EAS, ESR, and mass-spectrometry: a displacement of Br^? ions accompanied by the reduction of osmium to oxidation state +2 occurs in DMSO, a solvation with displacement of DMSO molecules is observed at the first stage in water and methanol (rate constants 2.3 × 10^?4 and 1.7 × 10^?3 s^?1, respectively), the sequential substitution of DMSO molecules and osmium oxidation to form [Os^IVBr₆]_2? ions takes place in 4 mol/L HBr.     

Synthese und strukturuntersuchungen von zwei stannylwolframpentacarbonylen R2Sn-W(CO)5 (R = (o-dimethylaminomethyl)phenyl bzw. (o-diphenylphosphinomethyl)phenyl)

The compounds [o-C₆-H₄CH₂E]₂Sn-W(CO)₅, (E = NMe₂ (1) or PPh₂ (2)) have been prepared by reaction of o-LiC₆H₄CH₂E with pentacarbonyltungsten tin(II) chloride (CO)₅WSnCl₂. The complexes were characterized by ¹³C, ³¹P, and ¹¹⁹Sn NMR spectroscopy and by X-ray diffraction analyses. 1 crystallizes monoclinically in the space group C/c (no. 15) with a 1310.2(4), b 1552.1(4), c 1202.9(4) pm, β 90.11(4)°, and Z = 4. 2 crystallizes monoclinically in the space goup P2₁/n (no. 14) with a 2108.1(4), b 1707.7(4), c 1283.7(3) pm, β 97.47(2)° and Z = 4. The structures were refined to final R values of 0.029 and 0.039, respectively.The SnW bond distances of 274.9 and 276.2 pm are very similar in both complexes. The Sn atoms are penta-coordinated by 2C, 2N and W in 1 and by 2C, 2P and W in 2. The penta-coordination comprises one SnW and two SnC single bonds, and either a SnN (in 1) or a SnP bond (in 2) of bond order 0.45. In the stannyl group of 1 the SnN bond distances both are identical by symmetry (256.4 pm), whereas the two SnP bond lengths of 2 differ to some extent (283.1 and 301.2 pm).     

New hydrogen-bonded dimeric and polymeric gold(I) complexes of the heterodifunctional ligand Ph2PNHP(O)Ph2

The preparation of several new gold(I) complexes by chloride metathesis of [AuCl(HL)] [HL=Ph₂PNHP(O)Ph₂] with either HL or K[Ph₂P(E)NP(E)Ph₂] (E=S or Se) is described. All compounds were characterised by a combination of ³¹P{¹H}, ¹H and IR spectroscopy, microanalysis and X-ray crystallography. X-ray structural studies reveal that [Au(HL)₂]Cl [monoclinic, space group P2₁/c, a=9.0726(3) Å, b=21.0847(6) Å, c=12.0131(3) Å, β=105.1090(10)°, V=2219 ų, Z=2, final R=3.97] forms a one dimensional polymeric structure in which alternating [Au(HL)₂]⁺ and Cl⁻ ions are linked through intermolecular N–H⋯Cl hydrogen-bonding. In contrast the three-co-ordinate compound [Au{Ph₂P(Se)NP(Se)Ph₂-Se,Se′}(HL)] [monoclinic, space group P2₁/a, a=21.6752(5) Å, b=9.1200(10) Å, c=24.0742(7) Å, β=106.080(2)°, V=4573 ų, Z=4, final R=8.94] forms hydrogen-bonded dimer pairs analogous to that previously observed in non-complexed HL. The X-ray crystal structure of the gold(I) precursor [AuCl(HL)] has also been determined: monoclinic, space group P2₁/c, a=10.217(8) Å, b=23.256(5) Å, c=20.086(5) Å, β=101.15(4)°, V=4683 ų, Z=8, final R=5.2. The X-ray crystal structure reveals intermolecular N–H⋯OP hydrogen-bonding between adjacent [AuCl(HL)] molecules forming infinite chains.     

Catalytic oxidation of diorganotin(IV) carboxylates to mixed-ligand monoalkyltin(IV) carboxylates by Ag and structure characterization of the mixed-ligand monoalkyltin(IV) 2-pyridinecarboxylate (2-ClPhCH2)Sn(2-ClPhCO2)(O2CC5H4N-2)2

The complexes of the type (ArCH₂)₂SnO were catalytic-oxygenated by Ag⁺ and yielded mixed-ligand organotin(IV) complexes (ArCH₂)(2-C₅H₄NCO₂)₂(ArCOO)tin(IV) (Ar = C₆H₅ (1), 2-ClC₆H₄ (2), 2-CNC₆H₄ (3), 4-ClC₆H₄ (4), 4-CNC₆H₄ (5), 2-FC₆H₄ (6)). The complexes 1-6 are characterized by elemental analyses, IR and NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopies. Single X-ray crystal structure analysis has been determined, which reveals that the center tin atom of complex 2 is seven-coordinated geometry.     

Kinetics and mechanism of oxidation of dimethyl sulfide with molecular oxygen catalysed by K[RuIII(EDTA-H)Cl] complex in water-dioxan medium

Oxidation of dimethyl sulfide (Me₂S) with molecular oxygen catalysed by [Ru^III(EDTA)(H₂O)]⁻1a (EDTA = ethylenediaminetetraacetate anion) was studied spectrophotometrically in water-dioxan medium at constant pH 5.0 (acetic acid-acetate buffer) and ionic strength 0.2 M (KCl). The reaction proceeds through the formation of a [Ru^III(EDTA)(Me₂S)]⁻2 intermediate which undergoes oxidation with molecular oxygen to give dimethyl sulfoxide (Me₂SO) as the oxidation product. The rate of formation of 2 and its decomposition was followed spectrophotometrically by monitoring the reactions at 528 nm the characteristic peak of 2. The rate of formation of 2 was found to be first order in the concentrations of 1a and Me₂S. The rate of decomposition of 2 is independent of the concentration of Me₂S and is half-order with respect to oxygen concentration. Both the formation and decomposition reactions of 2 were studied at different temperatures, and the activation parameters ΔH≠ and ΔS≠ were determined. A suitable mechanism was proposed for the catalytic oxidation of dimethyl sulfide to dimethyl sulfoxide with molecular oxygen.     

Silver(I) complexes of bis[2-(diphenylphosphino)phenyl] ether

The reaction of AgOTf in dichloromethane with bis(2-(diphenylphosphino)phenyl) ether (DPEphos) in an equimolar ratio afforded a dinuclear complex [Ag₂(κ²-P,P′-DPEphos)₂(μ-OTf)₂] (1), whereas the similar reaction in a 1:2 molar ratio resulted in the formation of a bis-chelating complex [Ag(κ²-P,P′-DPEphos)₂][OTf] (2). The silver(I) complex 1 was obtained as a dimer, in which two silver atoms are bridged by two triflate groups to form three adjacent eight-membered spirocyclic rings. The mixed-ligand complex [Ag(κ²-P,P′-DPEphos)(2,2′-bpy)][OTf] (3) was obtained in the reaction of 1 in dichloromethane with 2,2′-bipyridine. The crystal structures of complexes 1–3 were determined by single crystal X-ray analyses.     

Charge density studies on [(NO)Fe(S2C6H4)2][PPN] and [(NO)3Fe(S2C6H4)3] complexes

Charge density studies of chemical bonds for two iron complexes, [(NO)Fe(S,S-C₆H₄)₂] [PPN] (1), where PPN = N(Pph₃)₂ and Fe₃(NO)₃(S,S-C₆H₄)₃ (2) are investigated in terms of the topological properties at bond critical points based on the ‘atoms in molecule’ theory. The one electron reduction form (1R) of complex 1 and the one electron oxidation form (2O) of complex 2 are also included for comparison. The X-ray absorption spectroscopy of Fe K- and L_III,II-edges, as well as the N/S K-edge are applied to verify the illustration in the variation of the electronic structures. Based on the ρ_c, ?²ρ_c, and H_b values among the compound studied, Fe-S/N can be regarded as polarized covalent bond, and Fe-N bonds show stronger covalent character than that of the Fe–S bond, which is believed to be a highly polarized covalent bond.     

Self-assembly of extended Schiff base amino acetate skeletons, 2-{[(2Z)-(3-hydroxy-1-methyl-2-butenylidene)]amino}phenylpropionate and 2-{[(E)-1-(2-hydroxyaryl)alkylidene]amino}phenylpropionate skeletons incorporating organotin(IV) moieties: Synthesis,spectroscopic characterization,crystal structures,and in vitro cytotoxic activity

The organotin(IV) compounds, [Ph₃SnL¹H]_n · nCCl₄ (1), [Me₂SnL²(OH₂)] (2), [ⁿBu₂SnL²] (3), [Ph₂SnL²]_n (4), [Ph₃SnL²H]_n (5) and [Ph₃SnL³H]_n (7) (L¹ = 2-{[(2Z)-(3-hydroxy-1-methyl-2-butenylidene)]amino}phenylpropionate and L²⁻³ = 2-{[(E)-1-(2-hydroxyaryl)alkylidene]amino}phenylpropionate), were synthesized by treating the appropriate organotin(IV) chloride(s) with the potassium salt of the ligand in a suitable solvent, while [ⁿBu₂SnL³(OH₂)] (6) was obtained by reacting the acid form of L³ (generated in situ) with ⁿBu₂SnO. These complexes have been characterized by ¹H, ¹³C, ¹¹⁹Sn NMR, ESI-MS, IR and ^119mSn Mössbauer spectroscopic techniques in combination with elemental analyses. The crystal structures of 1 and 4–7 were determined. The crystal structures of complexes 1, 5 and 7 reveal that the complexes exist as polymeric chains in which the L-bridged Sn-atoms adopt a trans-R₃SnO₂ trigonal bipyramidal configuration with R groups in the equatorial positions and the axial locations occupied by a carboxylate oxygen from the carboxylate ligand and the alcoholic or phenolic oxygen of the next carboxylate ligand in the chain. The carboxylate ligands coordinate in the zwitterionic form with the alcoholic/phenolic proton moved to the nearby nitrogen atom. A polymeric zig-zag cis-bridged chain structure is observed for 4, without considering the weak Sn⋯O interaction, the Sn-atom having a slightly distorted trigonal bipyramidal coordination geometry with the two O atoms of the tridentate amino propionate ligand in axial positions. On the other hand, the structure of 6 reveals a monomeric molecule in which the Sn-atom has a distorted octahedral coordination geometry involving the tridentate carboxylate ligand, two n-butyl ligands occupying trans-positions and one water ligand. The in vitro cytotoxic activity of triphenyltin(IV) compounds, viz., 1, 5 and 7 against WIDR, M19 MEL, A498, IGROV, H226, MCF7 and EVSA-T human tumor cell lines are also reported.     

Monomeric five-coordinate rhenium diazenido and hydrazido complexes with aromatic thiolate ligands: X-ray structures of [Re(NNC6H4-Br)2(SC6H3-2,5-Me2)(PPh3)2] and [ReO(NNMePh)(SPh)3], and of the synthetic precursor [Re(NNC6H4-4-Br)2Cl(PPh3)2]

Reaction of [ReOCl₃(PPh₃)₂] with bromophenylhydrazine in methanol yields [ReCl(N₂C₆H₄Br)₂(PPh₃)₂] (1). Complex 1 reacts with arylthiolates to give mixtures of [Re(SAr)(N₂C₆H₄Br)₂(PPh₃)₂] (2) and [Re₂(SAr)₇(NNR)₂]⁻. Complexes 1 and 2 display trigonal bipyramidal geometries with the phosphine ligands occupying the axial sites. A significant feature of the structures is the nonequivalence of the rhenium-diazenido moieties, such that for 1 the ReN(1) and N(1)N(2) distances are 1.80(2) and 1.24(3) Å, while ReN(3) and N(3)N(4) are 1.73(2) and 1.32(3) Å, and for 2 the ReN distances are 1.73(1) and 1.80(2)° with corresponding NN distances of 1.32(2) and 1.25(2) Å. Reaction of (PPh₄)[ReO(SPh)₄] (3) with unsymmetrically disubstituted hydrazines affords complexes of the type [ReO(SPh)₃(NMRR′)] (R = Me, R′ = Ph for 4). Complexes 3 and 4 display distorted square pyramidal geometries with the oxo groups apical. The significant feature of the structure of 4 is the nonlinear ReN(1)N(2) linkage, exhibiting an angle of 145.6(10)°. The angle does not appear to correlate with a significant contribution from a valence form with sp² hybridization at the α-nitrogen. Crystal data: 1: monoclinic space group, P2₁/n, a = 12.216(2) Å, b = 19.098(2) Å, c = 20.257(4) Å, β = 106.20(1)°, V = 4538.3(8) ų to give Z = 4; structure solution and refinement based on 1905 reflections converged at R = 0.070. 2: monoclinic space group P2₁/n, a = 14.393(2) Å, b = 18.842(3) Å, c = 20.717(4)Å, β = 110.26(1)°, V = 5270.5(8) ų to give Z = 4 for D = 1.53 g cm⁻¹; structure solution and refinement based on 4249 reflections to give R = 0.070. 3: monoclinic space group P2₁/n, a = 12.531(2) Å, b = 24.577(4) Å, c = 16.922(3) Å, β = 99.06(1)°, V = 5146.2(9) ų, D = 1.36 g cm⁻³ for Z = 4, 2912 reflections, R = 0.050. 4: monoclinic space group p2₁/n, a = 16.137(2) Å, b = 9.863(2) Å, c = 16.668(2) Å, β = 111.12(1)°, V = 2474.7(6) ų, D = 1.74 g cm⁻³ for Z = 4, 2940 reflections, R = 0.066.     

The solution constitution of the roussin ester Fe2(SBu-t)2(NO)4

The¹H and¹⁵N NMR spectra of the Roussin ester Fe₂(SBu-t)₂(NO)₄ show that in solution it exists as a mixture of two isomeric forms (I andII), of C_2h- and C_2v- symmetry, respectively. Unlike other similar esters, Fe₂(SR)₂(NO)₄, the isomers are present in non-equal proportions: the equilibrium constant K = [II]/[I] is unchanged in the temperature range 220–298 K, indicating that entropy factors are primarily responsible for the unequal abundance ofI andII.     

Tricarbonylrhenium(I) and manganese(I) complexes of 2-(pyrazolyl)-4-toluidine

A series of tricarbonyl rhenium(I) and manganese(I) complexes of the electroactive 2-(pyrazolyl)-4-toluidine ligand, H(pzAn^Me), has been prepared and characterized including by single crystal X-ray diffraction studies. The reactions between H(pzAn^Me) and M(CO)₅Br afford fac-MBr(CO)₃[H(pzAn^Me)] (M = Mn, 1a; Re, 1b) complexes. The ionic species {fac-M(CH₃CN)(CO)₃[H(pzAn^Me)]}(PF₆) (M = Mn, 2a; Re, 2b) were prepared by metathesis of 1a or 1b with TlPF₆ in acetonitrile. Complexes 1a and 1b partly ionize to {M(CH₃CN)(CO)₃[H(pzAn^Me)]⁺}(Br⁻) in CH₃CN but retain their integrity in less donating solvents such as acetone or CH₂Cl₂. Each of the four metal complexes reacts with (NEt₄)(OH) in CH₃CN to give poorly-soluble crystalline [fac-M(CO)₃(μ-pzAn^Me)]₂ (M = Mn, 3a; Re, 3b). The solid state structures of 3a and 3b are of centrosymmetric dimeric species with bridging amido nitrogens and with pyrazolyls disposed trans- to the central planar M₂N₂ metallacycle. In stark contrast to the diphenylboryl derivatives, Ph₂B(pzAn^Me), none of the tricarbonyl group 7 metal complexes are luminescent.     

Syntheses and structures of iron carbonyl complexes derived from N-(5-methyl-2-thienylmethylidene)-2-thiolethylamine and N-(6-methyl-2-pyridylmethylidene)-2-thiolethylamine

The reaction of N-(5-methyl-2-thienylmethylidene)-2-thiolethylamine (1) with Fe₂(CO)₉ in refluxing acetonitrile yielded di-(μ₃-thia)nonacarbonyltriiron (2), μ-[N-(5-methyl-2-thienylmethyl)-η¹:η¹(N);η¹:η¹(S)-2-thiolatoethylamido]hexacarbonyldiiron (3), and N-(5-methyl-2-thienylmethylidene)amine (4). If the reaction was carried out at 45 °C, di-μ-[N-(5-methyl-2-thienylmethylidene)-η¹(N);η¹(S)-2-thiolethylamino]-μ-carbonyl-tetracarbonyldiiron (5) and trace amount of 4 were obtained. Stirring 5 in refluxing acetonitrile led to the thermal decomposition of 5, and ligand 1 was recovered quantitatively. However, in the presence of excess amount of Fe₂(CO)₉ in refluxing acetonitrile, complex 5 was converted into 2-4. On the other hand, the reaction of N-(6-methyl-2-pyridylmethylidene)-2-thiolethylamine (6) with Fe₂(CO)₉ in refluxing acetonitrile produced 2, μ-[N-(6-methyl-2-pyridylmethyl)-η¹ (N_py);η¹:η¹(N); η¹:η¹(S)-2-thiolatoethylamido]pentacarbonyldiiron (7), and μ-[N-(6-methyl-2-pyridylmethylidene)-η²(C,N);η¹:η¹(S)-2- thiolethylamino]hexacarbonyldiiron (8). Reactions of both complex 7 and 8 with NOBF₄ gave μ-[(6-methyl-2-pyridylmethyl)-η¹(N_py);η¹:η¹(N);η¹:η¹(S)-2-thiolatoethylamido](acetonitrile)tricarbonylnitrosyldiiron (9). These reaction products were well characterized spectrally. The molecular structures of complexes 3, 7-9 have been determined by means of X-ray diffraction. Intramolecular 1,5-hydrogen shift from the thiol to the methine carbon was observed in complexes 3, 7, and 9.     

Peculiarities of the reaction of (SPY-5-34)-dichloro-(κ2(C,O)-2-formylbenzylidene)(1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene)ruthenium with potassium hydridotris(pyrazolyl)borate

The reaction of (SPY-5-34)-dichloro-(κ²(C,O)-2-formylbenzylidene)(H₂IMes)ruthenium (H₂IMes=1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene) with potassium hydridotris(pyrazolyl)borate (KTp) in dichloromethane yielded an unusual ruthenium complex chloro(κ³(N,N,N)-chlorotris(pyrazolyl)borate)(κ²(C,C)-1-(2,4,6-trimethylphenyl)-3-(4,6-dimethylphenyl-2-methylidene)-4,5-dihydroimidazol-2-ylidene)ruthenium (2). In 2, a chlorotris(pyrazolyl)borate ligand, which had been created during this reaction, binds in κ³(N,N,N)-mode to the central ruthenium atom. Additionally, a double C–H activation of a methyl group of the H₂IMes resulted in the formation of a chelating N-heterocyclic biscarbene ligand and liberation of the former 2-formylbenzylidene as 2-methylbenzaldehyde. Formally, a double hydrogen transfer from a methyl group of the H₂IMes to the initial carbene carbon occurred. 2 was characterized by NMR spectroscopy, elemental analysis and single crystal X-ray structure determination. The reaction of KTp with (SPY-5-34)-dichloro(κ²(C,O)-2-ethoxycarbonylbenzylidene)(H₂IMes)ruthenium, on the other hand, gave the expected product chloro(κ³(N,N,N)-hydridotris(pyrazolyl)borate)(H₂IMes)(2-ethoxycarbonylbenzylidene)ruthenium (6). Compound 6 was characterized by NMR spectroscopy, elemental analysis and single crystal X-ray structure determination. Investigations of the relative activities of these complexes in model ring opening metathesis polymerizations showed a pronounced thermal latency. Polymerizations proceeded at temperatures above 100 °C in case of 6 and 130 °C in case of 2.     

Synthesis and spectroscopic characterization of [CoIII(salophen)(amine)2]ClO4 (amine=morpholine,pyrrolidine, and piperidine) complexes. The crystal structures of [CoIII(salophen)(morpholine)2]ClO4 and [CoIII(salophen)(pyrrolidine)2]ClO4

Three Co(III) complexes of the type [Co(salophen)(amine)₂]ClO₄, salophen=N,N′-disalicylidene-1,2-phenylendiamine dianion and amine=morpholine (1), pyrrolidine (2), and piperidine (3), have been synthesized and characterized by elemental analysis, IR, UV–Vis, ¹H, and ¹³C NMR spectroscopy. [Co(salophen)(morpholine)₂]ClO₄ (1) and [Co(salophen)(pyrrolidine)₂]ClO₄ (2) have been studied by X-ray diffraction. Compound 1 crystallizes in ribbons of complexes and perchlorates held together by weak NH⋯O and CH⋯O hydrogen bonds between morpholines and perchlorates. The latter also interconnect the chains to a 3D network. Some minor π–π interactions exist. Compound 2 crystallizes as endless chains of complexes linked by weak CH⋯O hydrogen bonds to the disordered perchlorates. The pyrrolidine moiety is turned by 90° with respect to 1 and forms intramolecular NH⋯O hydrogen bonds. The coordination polyhedra of 1 and 2 possess C_s symmetry, and the salophens are not planar in either of them.     

Asymmetric synthesis of 2-alkyl-3-thiazoline carboxylates: stereochemistry of the MnO2-mediated oxidation of cis- and trans-2-alkyl-thiazolidine-(4R)-carboxylates

The asymmetric synthesis of a series of 3-thiazoline carboxylates, 2, was effected by MnO₂ oxidation of the corresponding cis/trans thiazolidines, 1. The stereochemistry of the oxidation reaction was studied using NMR and chiral GC analyses. Compounds 2 were obtained with enantiomeric excesses (e.e.s) in the range of 40–100%.     

Phase diagrams for the [Th(NO3)4(TBP)2]-decane-[UO2(NO3)2(TBP)2] liquid ternary system

We report a phase diagram (on the mole fraction scale) for the [Th(NO₃)₄(TBP)₂]-decane-[UO₂(NO₃)₂(TBP)₂](1-2-3) ternary liquid system, where TBP stands for tributyl phosphate, at T = 298.15 K. This system is characterized by a homogeneous solution field and a two-liquid field (immiscibility field); one phase (phase I) is enriched in [Th(NO₃)₄(TBP)₂] and [UO₂(NO₃)₂(TBP)₂], and the other (phase II) is enriched in decane. Molecular interaction parameters and excess Gibbs energies G ^ex were calculated for the binary systems and the ternary liquid system along the binodal curve proceeding from miscibility in the [Th(NO₃)₄(TBP)₂]-decane system and the ternary system and using equations of the NTRL model. For the ternary system, G ^ex > 0. G ^ex decreases in the following order of pairs of liquids: (1, 2) > (2, 3) > (1, 3).     

Cu(I) cloride complexes with 4,5-(2-pyridylethylene)dithio-1,3-dithiol-2-thione and triphenylphosphine

Heteroligand binuclear complexes of CuCl with triphenylphosphine and 5-pyridine-2-yl-5,6-dihydro-[1,3]dithiolo[4,5-b][1,4]dithiine-2-thione (L¹) of the compositions [CuCl(PPh₃)(L¹)]₂ (I) and [CuCiL¹]₂ (II) are synthesized and studied by X-ray diffraction method. Crystals I are monoclinic; space group P2₁/n, a=8.9520(18) Å, b=18.926(4) Å, c=16.841(3) Å, β=94.96(3)°, Z=2. The Cu(I) atom has a quasi-tetrahedral surrounding involving the tetraphenylphosphine P atom, the pyridyl N atom of the molecule L¹, and two bridging Cl atoms. Crystals II are monoclinic; space group P2₁/c, a=9.3520(19) Å, b=8.1490(16) Å, c=18.660(4) A, β = 104.43(3)°, Z = 2. Both L¹ ligands in complex II act as bridges. The Cu(I) atom also has a quasi-tetrahedral surrounding formed by the Cl atoms, the pyridyl N atoms and thiol S atom of one L¹ ligand, and the thione S atom of the second L¹ ligand. Similar binuclear complexes with the bridging function of the L¹ ligand were also detected in a solution of II by the ESI method.