Homoleptic complexes [Ru(L-L)3]2+ (L-L=diphosphine,diarsine)

Homoleptic Ru(II)–diphosphine and Ru(II)–diarsine complexes [Ru(L-L)₃](OTf)₂ (L-L=Me₂P(CH₂)_nPMe₂; n=1, dmpm; n=2, dmpe) and 1,2-C₆H₄(AsMe₂)₂ (diars) have been isolated, in which the Ru(II) state is stabilised to an unprecedented degree, and the crystal structure of [Ru(diars)₃]Cl₂ has been determined.     

Electropolymerization and characterization of terpyridinyl iron (II) and ruthenium (II) complexes

Electroactive 2,2′: 6,2″-terpyridinyl ligands ( 3, 5, 6 ) and their iron(II) ( 7a–9a ) and ruthenium(II) complexes ( 7b–9b ) were synthesized. Bis[3-(aminophenyl)-2,2′ :6,2″-terpyridinyl]metal(II) complexes ( 7a, 7b ) and bis[2-(hydroxyphenyl)-2,2′ :6,2″-terpyridinyl]metal(II) complexes ( 8a, 8b ) were electropolymerized on to the surface of Pt or In-SnO₂ (ITO) electrodes in acetonitrile containing Bu₄NCIO₄ by scanning the potential between O and + 1.6V (for 7a and 7b ), and ?0.8 and +1.6V (for 8a and 8b ) versus saturated calomel electrode. The electrodes obtained by electropolymerization exhibited reversible electrochromism based on Fe(II)/Fe(III) or Ru(II)/Ru(III) redox couple. Photoresponses to visible light were found in the modified electrode obtained by electropolymerization of ruthenium complex 7b in an aqueous LiClO₄ solution containing methylviologen (cation MV²⁺) under an O₂ atmosphere. The mechanism for the photoresponded cathodic current was explained in terms of an excitation of bis(terpyridinyl)ruthenium(II) complex [Ru(terpy)²₂⁺] by visible light, an electron transfer from the excited state [Ru(terpy)^2+*₂] to MV²⁺, reduction of Ru(terpy)³⁺₂ at an electrode, and oxidation of MV^+* with O₂.     

Polymer Complexes XLV. Spectral Studies on Metal-Ligand Bonding in Novel Poly-Schiff Base Complexes

Polymer complexes derived from cinnamaldehyde and 2-substituted aniline with Cu(II), Pd(II), Pt(II), UO₂(II), Rh(III), Ru(III), and Pd(IV) have been synthesized and characterized by IR, electronic, EPR, ¹H-NMR, and ¹³C-NMR spectra, as well as by elemental analysis, thermogravimetry, and magnetic susceptibility measurements. The important bands in the IR spectra and the main ¹H- and ¹³C-NMR signals are assigned and discussed in relation to molecular structure. The wavelengths of the principal electronic absorption peaks have been accounted for quantitatively in terms of crystal field theory and various parameters were evaluated. The complexes, [Ru(HL _n )Cl₃] _n , are penta-coordinate; and, a trigonal-bipyramidal environment is commensurate for the Ru(III) ion. The presence of a coordinated water molecule in complex the Cu(II) complex (20) was demonstrated by thermogravimetry. The compounds, [N-(3-phenylacrylidene)-2-mercaptoaniline] (HL₁) and cinnamaldehyde-2-aminophenol (HL₂), act as monobasic and neutral bidentate ligands. The B-value suggests a strong covalency in the metal-ligand -bond. Tentative structures of the polymer complexes are proposed.     

Synthesis, characterization and crystal structure of a novel thiocyanate–ruthenium(II) complex

The cis-[Ru(dppb)(Me-bipy)(NCS)₂], dppb = 1,4-bis (diphenylphosphino)butane, Me-bipy = 4,4′-dimethyl-2,2′-bipyridine, and NCS = thiocyanate, was synthesized and characterized by spectroscopic and electrochemical techniques and its structure was determined by crystal X-ray analysis. The crystal structure reveals that the coordination geometry around the Ru(II) center is distorted octahedron where two molecules of thiocyanate are bonded to the ruthenium through nitrogen atom in cis orientation. The half-wave formal potential value E_1/2 = 0.8 V (versus Ag/AgCl) observed is considerable higher than that for the cis-[RuCl₂(dppb)(Me-bipy)] complex, E_1/2 = 0.6 V (versus Ag/AgCl), well illustrating the strong π-acceptor effect the NCS ligand toward the backbonding interaction with the Ru(II) metal center. The MLCT absorption bands of the thiocyanate complex present a higher molar absorptivity (about 12%) compared with the cis-[RuCl₂(dppb)(Me-bipy)] complex, in the same experimental conditions. These properties make the complex potentially promising for the photosensitization process.     

Construction of two photoluminescent sulfur-containing cadmium(II) coordination polymers with 4-connected topology based on a methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate ligand

Two new Sulfur-containing Cadmium(II) coordination polymers {[Cd(HL)₂](2H₂O)}_n (1) and {[Cd(L)(bmie)(H₂O)](H₂O)}_n (2) (H₂L = methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate, and bmie = 1,2-bis(imidazol-1′-yl)ethane) have been successfully constructed and structurally characterized by the single-crystal X-ray diffraction and other characterization techniques, such as elemental analysis, IR spectroscopy and thermogravimetric analysis. Structural analyses reveal that complex 1 exhibits a hydrogen bonded-extended 3D supramolecular structure based upon 4-connected sql layers assembled from single Cd(II) centers as nodes. Complex 2 features a 3D network which can be rationalized as a rare 4-connected cdl topology. It is shown that the H₂L ligand is a suitable building block in constructing coordination polymers with structural diversities. Moreover, solid photoluminescent properties have been investigated.     

Polymetallic complexes. part iii. schiff base complexes of cobalt(ii), copper(ii), cadmium(ii) and mercury(ii)

Eight polymetallic complexes have been synthesised of the composition M₂L₂._nB [M = Co(II), n = 4, B=H₂O, M = Cu(II), Cd(II) and Hg(II), n = 0] M₂L_2'.nB [M = Co(II), n = 4, B = H₂O; M = Cu(II), Cd(II) and Hg(II), n = 0], LH₂ = bi-bidentate Schiff base derived from benzoin with m-phenylenediamine; L'Hz = tridentate Schiff base derived from benzoin with o-aminophenol. Elemental analysis, conductance, magnetic susceptibility, i.r. and electronic spectral measurements have been done to characterise the complex compounds. A dinuclear octahedral configuration has been assigned to the cobalt(II) complexes and a dinuclear square planar structure to the copper(II) complexes. A tetrahedral configuration has been attributed to the cadmiurn(II) and mercury(II) complexes.     

Synthesis of New Polyimides from Ru (II) Complex of 2,6-bis [1-(p-dimethylaminophenylimino) Ethyl] Pyridine

Pyridine-based tridentate ligand containing pendant NMe₂ unit was used to prepare novel polyimides via one-stage solution polycondensation due to their stability under a variety of oxidative and reductive conditions. Ru (II) complex of the pydim ligand was synthesized starting from [RuCl₂ (p-cymene)]₂ and 2,6-bis [1-(p-dimethylaminophenylimino) ethyl] pyridine. A series of stable polyimides were synthesized from Ru (II) complex of 2,6-bis [1-(p-dimethylaminophenylimino) ethyl] pyridine (2) and various aromatic dianhyrides had inherent viscosities ranging from 1.31 to 1.55 dL/g and were soluble in polar solvents. The glass transition temperatures were 245–308°C, and the 10% weight loss temperatures were above 482–548°C.     

Sonochemical Syntheses of Nano-Scale Mixed-Ligand Lead(II) Coordination Polymers; Different Nano-Structures with Different Anions

Nano-structures of three new Pb(II) coordination polymers, [Pb(3-pyc)(N₃)(H₂O)] _n (1), [Pb(3-pyc)I] _n (2), and [Pb(3-pyc)Br] _n (3), {3-Hpyc =3-pyridinecarboxylic acid}, were synthesized by a sonochemical method. The new nano-structures were characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. Compound 1 and 2 were structurally characterized by single-crystal X-ray diffraction and consists of two and three-dimensional coordination polymers, respectively. The thermal stability of compounds 1–3 were studied by thermal gravimetric and differential thermal analyses and compared. This study demonstrates the sonochemical may be suitable method for the preparation of nanoscale coordination polymers and dependent on their packing they may produce different and interesting morphologies.     

Polyimides from a Novel Monomer 3,6-Bis(dimethylamino)acridine(p-cymene)dichlororuthenium(II) for a Catalytic Application

Tricyclic heteroaraomatic dye-based monomer containing NMe₂ units, 6-bis(dimethylamino)acridine(p-cymene)dichlororuthenium (II), was used to prepare novel polyimides via a one-stage solution polycondensation due to their stability under a variety of oxidative and reductive conditions. The Ru(II) complex monomer was synthesized starting from [RuCl₂(p-cymene)]₂ and 3,6-bis(dimethylamino)acridine. A series of stable polyimides was synthesized from the Ru(II) complex of 3,6-bis(dimethylamino)acridine and various aromatic dianhyrides. The polymers had inherent viscosities ranging from 1.72 to 2.11 dL/g and were soluble in polar solvents. The glass transition temperatures were 192–278 °C, and the 10% weight loss temperatures were above 503–635 °C. Ruthenium-substituted polyimides were tested for catalytic activity in the furan formation reaction of (Z)-3-methylpent-2-en-4-yn-1-ol. The polymeric catalyst was added to (Z)-3-methylpent-2-en-4-yn-l-ol without a solvent and the pure furan was isolated by distillation under reduced pressure. The conversion of the starting, enynol, was determined by gas chromatography (GC).     

Synthesis and Characterization of Zinc(II) Oxide Nanoparticles by Thermal Decomposition of Two Zinc(II) Nitrite Coordination Polymer Precursors

Two zinc(II) coordination polymers, {[Zn(3-bpdb)(NO₂)]·0.5H₂O} _n (1) and [Zn(4-bpdb)(NO₂)₂] _n (2), 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene and 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene}, have been synthesized and characterized by elemental analyses and IR spectroscopy. Nanoparticles of zinc(II) oxide have been prepared by thermolyses of two different zinc(II) coordination polymers, 1–2. The nano-materials were characterized by scanning electron microscopy, X-ray powder diffraction and IR spectroscopy. The thermal stability of ZnO nano-particles was studied by thermal gravimetric and differential thermal analysis and showed that there is no loss of weight, which indicates that the products were zinc(II) oxide. This study demonstrates the coordination polymers may be suitable precursors for the preparation of nanoscale materials.     

Enantiopreferential DNA-binding of a novel dinuclear complex [(bpy)2Ru(bdptb)Ru(bpy)2]4+

A novel dinuclear ruthenium(II) complex [(bpy)₂Ru(bdptb)Ru(bpy)₂]⁴⁺ (bpy=2,2^′-bipyridyl; bdptb=2,2^′-bis(5,6-diphenyl-1,2,4-triazin-3-yl)-4,4^′-bipyridine) has been synthesized and characterized. The DNA-binding behaviors of this complex have been studied by viscosity, absorption and circular dichroism (CD) spectra. It has firstly been found that the dinuclear ruthenium(II) complex display the enantiopreferential DNA-binding after equilibrium dialysis.     

Search for Optimum Conditions of Extraction of Transition Metal Complexes with Alkylimidazoles. I. Extraction of the Co(II), Ni(II), and Zn(II) Complexes of 1-Methylimidazole and of the Co(II) and Zn(II) Complexes of 2-Methylimidazole

Abstract

It has been shown that for the Co(II), Zn(II), and Ni(II) complexes of 1-methylimidazole and for the Co(II) and Zn(II) complexes of 2-methylimidazole, the partition coefficient D between the aqueous and organic phases is proportional to the degree of formation α _n of a definite complex. Tetrahedral species have been found to be extracted with the Co(II) and Zn(II) complexes of 2-methylimidazole and with the Zn(II) complexes of 1-methylimidazole.     

Photochemistry of trichloro(phenylazo)bis(triphenylphosphine)ruthenium(II) induced by Ru to phenyldiazonium MLCT excitation

The complex trichloro(phenylazo)bis(triphenylphosphine)ruthenium(II) shows a longest-wavelength absorption at λ_max = 520 nm which is assigned to a Ru(II) → phenyldiazonium⁺ MLCT transition. MLCT excitation leads to the oxidation of the metal and reduction of the diazonium cation which decays to nitrogen and phenyl radical.     

Mechanism of cytotoxicity and cellular uptake of lipophilic inert dinuclear polypyridylruthenium(II) complexes

The accumulation, uptake mechanism, cytotoxicity, cellular localisation of—and mode of cell death induced by—dinuclear ruthenium(II) complexes ΔΔ/ΛΛ‐[{Ru(phen)₂}₂{μ‐bb_n}]⁴⁺ (Rubb_n), where phen is 1,10‐phenanthroline, bb_n is bis[4(4′‐methyl‐2,2′‐bipyridyl)]‐1,n‐alkane (n=2, 5, 7, 10, 12 or 16), and the corresponding mononuclear complexes containing the bb_n ligands, were studied in L1210 murine leukaemia cells. Cytotoxicity increased with linker chain length, and the ΔΔ‐Rubb₁₆ complex displayed the highest cytotoxicity of the series, with an IC₅₀ value of 5 μM , similar to that of carboplatin in the L1210 murine leukaemia cell line. Confocal microscopy and flow cytometry studies indicated that the complexes accumulate in the mitochondria of L1210 cells, with the magnitude of cellular uptake and accumulation increasing with linking chain length in the bb_n bridge of the metal complex. ΔΔ‐Rubb₁₆ entered the L1210 cells by passive diffusion (with a minor contribution from protein‐mediated active transport), inducing cell death via apoptosis. Additionally, metal‐complex uptake in leukaemia cells was approximately 16‐times that observed in healthy B cells highlighting that the bb_n series of complexes may have potential as selective anticancer drugs.     

Adsorption Behaviors of Platinum Group Metals in Simulated High Level Liquid Waste Using Macroporous (MOTDGA-TOA)/SiO2-P Silica-based Absorbent

As fundamental research for separation of platinum group metals (PGMs) from high level liquid waste (HLLW) by macroporous silica-based adsorbent, (MOTDGA-TOA)/SiO₂-P adsorbent was prepared by impregnation of N,N′-dimethyl-N,N′-di-n-octyl-thiodiglycolamide (MOTDGA) and Tri-n-octylamine (TOA) into silica/polymer composite support (SiO₂-P). The adsorption behavior of Ru(III), Rh(III), and Pd(II) in simulated HLLW onto the adsorbent were investigated by the batch method to obtain their corresponding equilibrium and kinetic data. The adsorbent showed strong adsorption for Pd(II) and the adsorption reached equilibrium within 2 hr. High distribution coefficient (K _d) values for Pd(II) were obtained in 0.1–1 M HNO₃ concentration. In addition, the use of both MOTDGA and TOA improved adsorption of Ru(III) and Rh(III) better than individual use of them. Especially, the K _d value for Ru(III) towards (MOTDGA-TOA)/SiO₂-P adsorbent was three times larger than that in the adsorption using only with MOTDGA or TOA as extractant. The adsorptions of Ru(III), Rh(III), and Pd(II) followed the Langmuir adsorption model, and were found to be controlled by the chemisorption mechanism.     

Synthesis and Gas Permeability of Novel Poly(diphenylacetylenes) Having Polyethylene Glycol Moieties

4-Trimethylsilyldiphenylacetylenes with methyl group or bromine atom (Me₃SiC₆H₄C≡CC₆H₄R, R = m-CH₃, p-CH₃, m-Br, p-Br, 1a–d, respectively) were polymerized with TaCl₅/ n-Bu₄Sn to afford poly(diphenylacetylene) derivatives (2a–d). The polymers (2a–d) had high molecular weight over 5×10⁵, and gave free-standing membranes by solution casting method. Chlorination of the obtained poly[1-(3-methylphenyl)-2-(4-trimethylsilyl)phenylacetylene] was carried out by using sulfuryl chloride, and then substitution of polyethylene glycol was performed to give poly(diphenylacetylene) possessing polyethylene glycol moieties. Its carbon dioxide permeability (P_{CO 2}) and permselectivity (P_{CO 2}/P_{N 2}) were 2,970 barrers and 9.0, respectively.     

Redox-induced linkage isomerization detected in [Ru(NH3)5(NVF)](PF6)2(NVF = N-vinylformamide)

A new ruthenium (II) complex, of formula [Ru(NH₃)₅(NVF)](PF₆)₂, 1 (with NVF = N-vinylformamide) was synthesized and characterized by chemical analyses, spectroscopic and electrochemical techniques. The presence of two coordination sites within NVF makes complex 1 capable of showing a redox-dependent linkage isomerization process, which was detected by cyclic voltammetry and spectroelectrochemical measurements. Upon oxidation of the metallic center from Ru (II) to Ru (III) of complex 1 in N,N-dimethylformamide, linkage isomerization takes place from a vinyl-coordinated Ru(II) to an amide-coordinated Ru(III). This is an additional example of a system that can be applied in molecular memory devices or engines of a molecular machine.     

Synthesis and Characterization of ZnO Nanoparticles via Thermal Decomposition of Two Zinc(II) Supramolecular Compounds

A new nano-sized Zn(II) complex, [Zn(5,5′-dtbu-2,2′-bipy)Cl₂] _n (1) was synthesized and its structure determined by X-ray crystallography. The new nano-sized complex was prepared at oleic acid as a surfactant at 280 °C and characterized by scanning electron microscopy, elemental analyses and IR spectroscopy. The ZnO nano-particles were synthesized from thermolysis of nano-compound 1 at 600 °C and similar compound, [Zn(5,5′-dimethyl-2,2′-bipy)Cl₂] _n (2), at two different methods. SEM images show the average size of ZnO nano-particles are 78 and 50 nm for the compounds 1 and 2, respectively.     

Homonuclear tris-dithiocarbamato ruthenium(III) complexes as single-molecule precursors for the synthesis of ruthenium(III) sulfide nanoparticles

Tris(N-phenyldithiocarbamato) ruthenium(III) complexes, [Ru(L¹)₃] (1); tris(N-(4-methylphenyl)dithiocarbamato)) ruthenium(III), [Ru(L²)₃] (2); and tris(N-(4-methoxyphenyl)dithiocarbamato)) ruthenium(III), [Ru(L³)₃] (3) were synthesized and characterized by elemental analysis, thermogravimetric analysis, FTIR, UV–VIS and NMR spectroscopy. TGA analyses show major degradation of all complexes in the range 120–350°C, leading to the formation of residual weight corresponding to ruthenium (III) sulfides. The ¹H-NMR spectra of the ligands and complexes are in agreement with the proposed structures. FTIR studies confirmed that the ligands coordinate the Ru³⁺ ion in a bidentate chelating mode. The complexes were thermolysed at 180°C to prepare hexadecylamine-capped Ru₂S₃ nanoparticles. Powder X-ray diffraction patterns revealed the formation of hexagonal-phase Ru₂S₃ nanoparticles with average crystallite sizes ranging from 8.3 to 9.5?nm. TEM images showed the crystalline clusters with shapes ranging from square to hexagonal, while SEM images elucidated that the particles were agglomerated. Energy-dispersive X-ray spectra confirmed the presents of Ru₂S₃ nanoparticles.     

Synthesis,characterization, and thermotropic properties of side-chain liquid crystalline polysiloxane polymers with an oligo(ethylene oxide) unit in the side chain

A series of new alkene and octenyloxy monomers containing 4′-[oligo(ethylene oxide)] n monomethyl ether 4-biphenyl ether carboxyl benzoate [MS3BDBE_n] (n = to 3) and 1- (p-methoxydiphenyl)–(carboxyl benzoate) [oligo(ethylene oxide)]n [MS_m+2BEnDB] (m = 1, 6; n = 1 to 3) as end groups were synthesized. The molecular structure of the monomers was charaterized using nuclear magnetic resonance (NMR) spectroscopy. These monomers were grafted onto poly(methylhydrosiloxane)s (PMHS) by the platinun-catalyzed hydrosilylation process. The thermal transition temeratures and mesophase textures of the monomers and the polysiloxane polymers have been determined by diffential scanning calorimetry (DSC) and by polarized optical microscopy. The effect of changes in chemical structure on the mesophase properties, glass transition temperature, isotropic temperature, and mesophase texture of the monomers and the polysiloxane polymers is discussed. Polymers PS3BDBEn showed smectic and nematic phases which were not analogous to their precursor nematic monomers MS3BDBEn. Both monomers MS_m+2BE_nDB and their polymeric homologous PS_m+2BE_nDB did not exhibit mesophase properties. This demonstrated that the polymer effect could not stabilize the mesophase obtained from mesogenic core which contained a flexible oligo(ethylene oxide) unit interconnecting aromatic group. © 1995 John Wiley & Sons, Inc.