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New Complexes (new + complex)
Selected AbstractsSynthesis, Structure and Characterization of Two New Complexes [Cu2(C3H2O4)2(C4H4N2)]·2H2O and [Zn2(OH2)2(C3H2O4)2(C4H4N2)]EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 6 2003Xiutang Zhang Abstract Two new complexes with three-dimensional extended frameworks linked by pyrazine and malonate ligands, namely [Cu2(C3H2O4)2(C4H4N2)]·2H2O and [Zn2(OH2)2(C3H2O4)2(C4H4N2)], have been prepared and characterized by X-ray crystallography, IR, EPR and UV/Vis spectroscopy, their magnetic properties and electrical conductivity. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Coordination complexes of functionalized pyrazines with metal ions: reagents for the controlled release of flavourant molecules at elevated temperaturesFLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2006Colin Baillie Abstract The potential for stabilization of volatile flavourant molecules such as functionalized pyrazines by coordination to metal ions, and the application of the resultant coordination complexes as controlled release agents at elevated temperatures were explored. New complexes containing the flavourant molecules 2,3,5-trimethylpyrazine (TMP), 2-ethyl-3-methylpyrazine (EMP) and 2-acetylpyrazine (ACP) with copper(II) and copper(I) salts were prepared and structurally characterized. Representative examples of known copper(II) and calcium(II) complexes containing pyrazine carboxylic acids were also prepared. The complexes were examined by thermal analysis techniques and demonstrated, by a combination of thermogravimetric (TGA) and pyrolysis GC,MS analyses, to act as convenient reagents for the release of the parent pyrazine at elevated temperatures. Thus, pyrolysis GC,MS revealed that the complex [Cu3Cl3(EMP)2]n cleanly releases EMP in 96.5% selectivity at 200 °C. Of particular significance is that the calcium complex [Ca(3-aminopyrazine-2-carboxylate)2·H2O], under ramped pyrolysis conditions, was shown to undergo decarboxylation prior to the release of 2-aminopyrazine (AMP), as essentially the only volatile component, in the temperature range 600,800 °C. This finding provides a precedent for the application of complexes of pyrazinecarboxylate salts with metal ions (of which an almost infinite number of combinations is potentially available) as controlled release agents of the parent pyrazine molecule at elevated temperatures, suitable for exploitation by the foodstuffs, flavour and fragrance industries. Copyright © 2006 John Wiley & Sons, Ltd. [source] Neptunium uptake by serum transferrinFEBS JOURNAL, Issue 7 2005Isabelle Llorens Although of major impact in terms of biological and environmental hazards, interactions of actinide cations with biological molecules are only partially understood. Human serum transferrin (Tf) is one of the major iron carriers in charge of iron regulation in the cell cycle and consequently contamination by actinide cations is a critical issue of nuclear toxicology. Combined X-ray absorption spectroscopy (XAS) and near infrared absorption spectrometry were used to characterize a new complex between Tf and Np (IV) with the synergistic nitrilotriacetic acid (NTA) anion. Description of the neptunium polyhedron within the iron coordination site is given. [source] Structure investigation of Maltacine C1a, C1b, C2a and C2b,cyclic peptide lactones of the Maltacine complex from Bacillus subtilisJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 10 2005Gunnar Hagelin Abstract A new complex of cyclic peptide lactone antibiotics from Bacillus subtilis, which we named Maltacines, has recently been described. The structure elucidation of four of them is reported in this paper. The amino acid sequences and structures of the peptides were found by MSn of the ring-opened linear peptides, which gave uninterrupted sequences of Bn and Y,n ions. The identities of three unknown residues in the sequences were solved by a combination of derivatisation with phenylisothiocyanate (PITC), high-resolution mass spectrometry and H/D exchange. The nature and position of the cyclic structure was disclosed by a chemo-selective ring opening with Na18OH and was found to be a lactone formed between a hydroxyl of residue number 4 and the C -terminal amino acid number 12. For verification of the structure of the B2+ ion, peptides with different combinations of P/Q and P/K at the N -terminus were synthesised. The structure of the four peptides were found to be: C1a and C2a: cyclo-4,12(P-Q-Y-Adip-V-E-T-Y-Orn-103-Y-I-OH) and C1b/C2b: cyclo-4,12(P-Q-Y-Adip-V-E-T-Y-K-103-Y-I-OH). Adip = aminodihydroxy pentanoic acid. Copyright © 2005 John Wiley & Sons, Ltd. [source] Structure investigation of Maltacine D1a, D1b and D1c,cyclic peptide lactones of the Maltacine complex from Bacillus subtilisJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 10 2005Gunnar Hagelin Abstract A new complex of cyclic peptide lactone antibiotics from Bacillus subtilis, which we named Maltacines has recently been described. The structure elucidation of three of them is reported in this paper. The amino acid sequences and structures of the peptides were found by MSn of the ring-opened linear peptides that gave uninterrupted sequences of Bn and Y,n ions. The identities of four unknown residues in the sequences were solved by a combination of derivatisation with phenylisothiocyanate (PITC), high-resolution mass spectrometry and H/D exchange. The nature and position of the cyclic structure was disclosed by a chemo-selective ring opening with Na18OH and was found to be a lactone formed between a hydroxyl of residue number 4 and the C -terminal amino acid number 12. For verification of the structure of the B2+ ion, peptides with different combinations of P/Q and P/K at the N -terminus were synthesized. The structures of the four peptides is tentatively suggested to be: D1a: cyclo(4,12)-P-Q-Y-Adip-A-E-T-Y-Orn-HGly-Y-I-OH, D1b: cyclo(4,12)-P-Q-Y-Adip-A-E-T-Y-Orn-S-Y-I-OH and D1c: cyclo(4,12)-P-Q-Y-Adip-A-E-T-Y-K-S-Y-I-OH. Adip = aminodihydroxy pentanoic acid and HGly = hydroxyglycine. Copyright © 2005 John Wiley & Sons, Ltd. [source] Synthesis, crystal structure and magnetic property of a two-dimensional herringbone-like network with praseodymium(III) nitrate and 1-bromo- 3,5-bis(imidazol-1-ylmethyl)benzene (bib)APPLIED ORGANOMETALLIC CHEMISTRY, Issue 6 2006Wen-Li Meng Abstract A new complex [Pr(bib)2(NO3)3] (1) was synthesized by reaction of bidentate imidazole-containing ligand 1-bromo-3,5-bis(imidazol-1-ylmethyl)benzene (bib) with Pr(NO3)·6H2O and characterized by X-ray crystallography. Complex 1 has a two-dimensional herringbone-like structure with the ligand bib serving as a bridging ligand using its two imidazolyl nitrogen atoms. Ligand bib adopts cis and trans two different conformations, and the Pr(III) atoms are bridged by bib in two different ways. Thermogravimetric analysis for complex 1 was carried out and the result shows that the complex is stable up to 180 °C. Variable-temperature magnetic susceptibility of complex 1 was measured between 1.8 and 300 K and the result shows that the ,MT value decreases continuously over the whole temperature range. Copyright © 2005 John Wiley & Sons, Ltd. [source] A Nonanuclear Copper(II) Polyoxometalate Assembled Around a ,-1,1,1,3,3,3-Azido Ligand and Its Parent Tetranuclear ComplexCHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2005Pierre Mialane Dr. Abstract Reaction of CuII, [,-SiW10O36]8,, and N3, affords three azido polyoxotungstate complexes. Two of them have been characterized by single-crystal X-ray diffraction. Complex KNaCs10[{,-SiW10O36Cu2(H2O)(N3)2}2],26,H2O (1) is obtained as crystals in few hours after addition of CsCl. This linear tetranuclear CuII complex consists in two [,-SiW10O36Cu2(H2O)(N3)2]6, units connected through two WO bridges. When the filtrate is left to stand for one night, a new complex is obtained. From both elemental analysis and IR spectroscopy, it has been postulated that this compound could be formulated K1.5Cs5.5[SiW10O37Cu2(H2O)2(N3)],14,H2O (1,a), showing the loss of one azido ligand per polyoxometalate unit. Finally, when no cesium salt is added to the reaction medium, the nonanuclear complex K12Na7[{SiW8O31Cu3(OH)(H2O)2(N3)}3(N3)],24,H2O (2) is obtained after three days. Compound 2 crystallizes in the R3c space group and consists in three {Cu3} units related by a C3 axis passing through the exceptional ,-1,1,1,3,3,3-azido bridging ligand. Each trinuclear CuII unit is embedded in the [,-SiW8O31]10, ligand, an unprecedented tetravacant polyoxometalate, showing that partial decomposition of the [,-SiW10O36]8, precursor occurs with time in such experimental conditions. Magnetically, complex 1 behaves as two isolated {Cu2(,1,1 -N3)2} pairs in which the metal centers are strongly ferromagnetically coupled (J=+224 cm,1, g=2.20), the coupling through the WO bridges being negligible. The magnetic behavior of complex 2 has also been studied. Relatively weak ferromagnetic couplings (J1=+1.0 cm,1, J2= +20.0 cm,1, g=2.17) have been found inside the {Cu3} units, while the intertrimeric magnetic interactions occurring through the hexadentate azido ligand have been found to be antiferromagnetic (J3=,5.4 cm,1) and ferromagnetic (J4=+1.3 cm,1) with respect to the end-to-end and end-on azido-bridged CuII pairs, respectively. [source] Synthesis, Crystal Structure of Co(II)(6-methoxybenzothiazole- 2-carboxylate)2(DMF)2 and Its Application to Carbonylation of Benzyl ChlorideCHINESE JOURNAL OF CHEMISTRY, Issue 1 2010Bin Zhang Abstract A new complex, Co(MBTC)2(DMF)2 (MBTC=6-methoxybenzothiazole-2-carboxylate, DMF=N,N -dime- thylformamide), was synthesized in DMF solution and characterized by single crystal X-ray diffraction analysis. Using the cobalt complex as catalyst, phenylacetic acid was prepared by the carbonylation of benzyl chloride with carbon monoxide (0.1 MPa). The effects of solvents, phase transfer catalysts and temperature on the reactions were investigated. The yield of phenylacetic acid was higher than 90% in optimized condition. [source] Studies in Solution and the Solid State of Coordination Compounds Derived from LiBH4, NaBH4, and Bidentate Aromatic AminesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2010Milagros Aguilar-Martínez Abstract The mixture of 2,2,-bipyridylamine, 2,2,-bipyridine, 1,10-phenanthroline, 1,2-phenylendiamine, and 1,4-phenylendiamine each with LiBH4 and NaBH4 in a 1:1 molar ratio in THF yields seven new complexes of the type MBH4·L-THF and one complex of the type MBH4·L. These compounds were characterized by IR and NMR spectroscopy and X-ray single-crystal structure determinations. In the solid state, the [BH4], group is bidentate, as deduced from the stretching patterns observed in IR spectra and confirmed by X-ray single-crystal structure analysis. NMR spectroscopy showed that all amines act as bidentate ligands and are symmetrically coordinated to the metal cation. Complexes LiBH4 -2,2,-bipyridine-THF (1), NaBH4 -2,2,-bipyridine-THF (2), LiBH4 -1,10-phenanthroline-THF (3), and NaBH4 -1,10-phenanthroline-THF (4) have a discrete molecular structure, whereas the complexes LiBH4 -1,2-phenylendiamine-THF (5), NaBH4 -1,2-phenylendiamine-THF (6), LiBH4 -2,2,-dipyridilamine (7), and LiBH4 -1,4-phenylendiamine-THF (8) have polymeric structures in the solid state. N -borane-dipyridylamine adduct 9 was isolated from an aged solution of 7. IR spectroscopy of the new complexes showed that the structures of complexes 1, 3, 4, and 6 are maintained in the solid state and in solution. A rotational barrier for the [BH4], group of less than 38 KJ,mol,1 was estimated for some of the new complexes. [source] Synthesis, Crystal Structure, and Catalytic Properties of Novel Dioxidomolybdenum(VI) Complexes with Tridentate Schiff Base Ligands in the Biomimetic and Highly Selective Oxygenation of Alkenes and SulfidesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 5 2010Abdolreza Rezaeifard Abstract Four novel dioxidomolybdenum(VI) complexes [MoO2(Lx)(CH3OH)] have been synthesized, using 2[(E)-(2-hydroxy-2-phenylethylimino)methyl]phenol derivatives as tridentate ONO donor Schiff base ligands (H2Lx) and MoO2(acac)2. A monoclinic space group was determined by X-ray crystallography from single-crystal data of a sample of these new complexes. The epoxidation of alkenes by using tert -butyl hydroperoxide and oxidation of sulfides to sulfoxides by urea hydrogen peroxide were efficiently enhanced with excellent selectivity under the catalytic influence these new MoVI complexes. The high efficiency and relative stability of the catalysts have been observed by turnover numbers and UV/Vis investigations. The electron-poor and bulky ligands promoted the effectiveness of the catalysts. [source] Spontaneous Reduction of High-Spin FeIII Complexes Supported by Benzoic Hydrazide Derivative LigandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 25 2009Nouri Bouslimani Abstract We report herein experimental evidence for the spontaneous reduction of new high-spin iron(III) FeIII(L(n))2Cl, L complexes to new high-spin iron(II) FeII(HL(n))2Cl2 mononuclear complexes. These processes were checked by EPR, cyclovoltammetric, and pseudo-steady voltammetric studies. Crystal structures of three new complexes (one FeIII and two FeII) were obtained from RX single-crystal diffraction.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] One-Dimensional Coordination Polymers of MnII, CuII, and ZnII Supported by Carboxylate-Appended (2-Pyridyl)alkylamine Ligands , Structure and MagnetismEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2009Himanshu Arora Abstract Four new complexes [MnII(L1OO)(H2O)][ClO4]·2H2O (1), [ZnII(L1OO)][ClO4]·2H2O (2), [CuII(L3OO)][CF3SO3]·H2O (3), and [ZnII(L3OO)][ClO4] (4) (L1OO, = 3-[(2-(pyridine-2-yl)ethyl){2-(pyridine-2-yl)methyl}amino]propionate; L3OO, = 3-[(2-(pyridine-2-yl)ethyl){(dimethylamino)ethyl}amino]propionate) have been synthesized and characterized by elemental analysis, IR, and UV/Vis spectroscopy. Structural analysis revealed that 1, 3, and 4 are one-dimensional chain-like coordination polymers. In 1 distorted octahedral MnN3O3 and in 3 square-pyramidal CuN3O2 coordination is satisfied by three nitrogen atoms and an appended carboxylate oxygen atom of the ligand, and an oxygen atom belonging to the carboxylate group of an adjacent molecule. In 4 trigonal bipyramidal ZnN3O2 coordination environment is provided by two nitrogen atoms and an appended carboxylate oxygen atom of the ligand in the equatorial plane, and the two axial positions are satisfied by a tertiary amine nitrogen and an oxygen atom belonging to the carboxylate group of an adjacent molecule. In 1 the MnII center is coordinated by an additional water molecule. In these complexes each monomeric unit is sequentially connected by syn - anti carboxylate bridges. Temperature-dependent magnetic susceptibilities for 1 and 3 are measured, revealing antiferromagnetic interactions through syn - anti carboxylate bridges between the MII centers. Analysis of the crystal packing diagram reveals that in 1 extensive ,,, stacking involving alternate pyridine rings of adjacent 1D chain exists, which eventually lead to the formation of a 2D network structure. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] A Simple Building-Block Route to (Phosphanyl-carbene)palladium Complexes via Intermolecular Addition of Functionalised Phosphanes to IsocyanidesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2009Michael R. Eberhard Abstract We present a straightforward protocol for making (phosphanyl-carbene)PdII complexes. These complexes have bidentate ligands containing an acyclic diamino- or aminooxy-carbene and a phosphane. The synthesis gives good yields (typically 70,90,%) for a variety of complexes (22 compounds). Moreover, it does not require the synthesis of imidazolium salts nor the a priori generation of free carbenes. Three of the new complexes were tested as catalysts for Sonogashira and Hay coupling reactions, with good yields and selectivities. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Pyrazole and Pyrazolyl Complexes of cis -Bis(2,2,-bipyridine)chlororuthenium(II): Synthesis, Structural and Electronic Characterization, and Acid-Base ChemistryEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 5 2009Hershel Jude Abstract Complexes of the type cis -[Ru(bpy)2(Cl)(L)]+ [bpy = 2,2,-bipyridine; with L = pyrazole (1H), 4-methylpyrazole (2H), and 3,5-dimethylpyrazole (3H)] were synthesized and isolated as hexafluorophosphate salts. The molecular structures of these new complexes were fully characterized by 1H NMR spectroscopy and ESI mass spectrometry, and the crystal structure of 3H·PF6 was determined by X-ray crystallography. Compound 3H·PF6 (C25H24ClF6N6PRu) crystallizes in the monoclinic space group P21/n with a = 12.102(2) Å, b = 16.826(3) Å, c = 13.016(2) Å, , = 92.606(2)°, V = 2647.6(8) Å3, and Z = 4. The crystal structure of 3H reveals the formation of an intramolecular hydrogen bond (2.562 Å) between the pyrazole N(2),H site and the chloride ligand. The redox and electronic absorption properties of 1H, 2H, and 3H, as well as their deprotonated counterparts [L = pyrazolate (1), 4-methylpyrazolate (2), and 3,5-dimethylpyrazolate (3)], were investigated by cyclic voltammetry and UV/Vis spectroscopy. For detailed analysis of the electronic nature of this series of pyrazolyl ligands, the results are discussed along with other relevant cis -[Ru(bpy)2(X)(Y)]n+ complexes. From spectrophotometric pH titrations, the basicity associated with the coordinated pyrazole/pyrazolate couple in water was found in all three cases to be unusually high, partly owing to the N,H···Cl hydrogen bond that stabilizes the protonated, azole state. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Reactivity and X-ray Structural Studies in Ligand Substitution of [Cp/(Ind)Ru(dppf)Cl] , Epimerisation in [Cp/(Ind)Ru(Josiphos)Cl] {Cp = ,5 -C5H5, Ind = ,5 -C7H9, dppf = 1,1,-Bis(diphenylphosphanyl)ferrocene, Josiphos = (R)-(,)-1-[(S)-2-(Diphenylphosphanyl)ferrocenyl]ethyldicyclohexylphosphane}EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2007Sin Yee Ng Abstract Ligand substitution of [(Ind)Ru(PPh3)2Cl] (1) led to the isolation of [(Ind)Ru(PPh3){Ph2P(CH2)2C9H7}Cl] (2), [(Ind)Ru(dppf)Cl] (3) and [(Ind)Ru{(Ph2PCH2)3CMe}]PF6 ([4]PF6), and diastereoisomers [(R)- and (S)-(Ind)Ru(Josiphos)Cl] [(R)- 5 and (S)- 5], where (R)-(S)-Josiphos is the ferrocene-based chiral diphosphane ligand (R)-(,)-1-[(S)-2-(diphenylphosphanyl)ferrocenyl] ethyldicyclohexylphosphane. The Cp analogues of 5, viz. (R)- 6 and (S)- 6, were also obtained from [CpRu(PPh3)2Cl] (1a). Josiphos-dependent epimerisation was observed, with conversion of the (S) isomer to the (R) isomer in both cases. Chloride abstraction of 3 with NaPF6 in CH3CN and NaN3 in EtOH gave [(Ind)Ru(dppf)(CH3CN)]PF6 ([7]PF6) and [(Ind)Ru(dppf)(N3)] (8), respectively. The azido ligand in 8 underwent [3+2] dipolar cycloaddition with dimethyl acetylenedicarboxylate to give a N -bound bis(methoxycarbonyl)-1,2,3-triazolato complex, 9. X-ray crystal structures of the new complexes, except (R)- 5, (S)- 5 and (S)- 6, have been determined. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Designed Assembly and Structures and Photoluminescence of a New Class of Discrete ZnII Complexes of 1H -1,10-Phenanthroline-2-oneEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2006Jie-Peng Zhang Abstract The hydrothermal reaction of 1H -1,10-phenanthroline-2-one (Hophen), zinc acetate, benzoic acid (Hba), and triethylamine (3.0 mL) yields the tetranuclear complex [Zn4(,3 -OH)2(ophen)4(ba)2] (2), which features a chair-like Zn4(,3 -OH)2 cluster with two ba ligands centrosymmetrically oriented. [(OAc){Zn3(,3 -OH)(ophen)3}(ox){Zn3(,3 -OH)(ophen)3}(OAc)] (3; ox = oxalate) was isolated when less triethylamine (1.0 mL) was used. Two Zn3(,3 -OH)(ophen)3 clusters in 3 are linked together by an oxalate to form a dumbbell-like structure in which the acetate and oxalate ligands point outward from the Zn3(,3 -OH)(ophen)3 cluster with an acute bending angle. A geometric analysis reveals that Zn3(,3 -OH)(ophen)3 and dicarboxylate with an obtuse bending angle cannot form an infinite zigzag chain, whereas the ring isomer can. With isophthalate (ipa), thiophene-2,5-dicarboxylate (tda), and 4,4,-oxybis(benzoate) (oba) instead of the acetate of 3 three new complexes, namely [{Zn3(,3 -OH)(ophen)3}(ipa)2{Zn3(,3 -OH)(ophen)3}]·0.5H2O (4), [{Zn3(,3 -OH)(ophen)3}(tda)2{Zn3(,3 -OH)(ophen)3}] (5), and [{Zn3(,3 -OH)(ophen)3}(oba)2{Zn3(,3 -OH)(ophen)3}] (6), were obtained in which two Zn3(,3 -OH)(ophen)3 clusters are linked by a pair of ipa, tda, or oba ligands to form isostructural, cluster-based 2:2 metallomacrocycles. Photoluminescence studies of 2,6 revealed that their luminescent properties are derived from ophen-based ,-,* excited states. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Synthesis, Characterization, and Properties of Some Copper(II) Complexes of 2-Pyridineformamide Thiosemicarbazone (HAm4DH)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 6 2006María del Carmen Aguirre Abstract Reactions between different copper(II) salts and 2-pyridineformamide thiosemicarbazone (HAm4DH) in neutral ethanolic media led to the formation of complexes with the formulae [Cu(HAm4DH)X2] (X = Cl or Br) (1, 2) and [Cu(HAm4DH)2]X2 (X = NO3 or ClO4) (3, 4). The same reactions carried out in the presence of triethylamine gave rise to new complexes with the general formulae [Cu(Am4DH)X] (X = Cl, Br, AcO, or NO3) (5,8), [Cu(H2O)(Am4DH)](ClO4) (9), and [Cu(Am4DH)2] (10), many of which were isolated with different molecules of crystallization and contain a deprotonated thiosemicarbazone (Am4DH). These complexes were characterized by elemental analysis, and different spectroscopic and magnetic techniques. The thermal and redox behavior of the complexes was also evaluated. Complexes 1, 2, 5, and 6 show better nuclease activity than [Cu(phen)2]2+. Inaddition, crystals were isolated in the cases of [Cu(HAm4DH)Cl2]2 (5a), 1,[Cu(Am4DH)Cl] (5b), 1,[Cu(Am4DH)Br] (6a), and [Cu(HAm4DH)(H2O)(ClO4)2]·MeOH·H2O (9a) and these structures were analyzed by X-ray diffraction. Compound 5a has a dimeric structure with chlorine bridges and shows weak antiferromagnetism (J = ,12.2 cm,1). Complexes 5b and 6a are one-dimensional polymers formed through halogen bridges and the deprotonated thiosemicarbazone in the thiolate form. In compound 9a the copper(II) is in a distorted octahedral environment with two ClO4 units coordinated to the metal center. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Tris(pyrazolyl)methane Ligands: Syntheses and Structures of Monometallic and Metallodendritic ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 16 2004Alberto Sánchez-Méndez Abstract The substituted ligands Me3SiC(pz)3 (1) and Me3SiOCH2C(pz)3 (2) have been prepared starting from HC(pz)3 and HOCH2C(pz)3. The molecular structure of compound 1 has been determined by X-ray diffraction studies, which show a propeller-like conformation of the pyrazolyl rings. Compound 2 has been found to be useful for the synthesis of [Mo(CO)3{Me3SiOCH2C(pz)3}] (3), [TiCl2(NtBu){Me3SiOCH2C(pz)3}] (4), and [PdCl2{Me3SiOCH2C(pz)3}] (5), through ligand exchange reactions. The characterization of the new complexes is compatible with a tridentate coordination of the ligands in complexes 3 and 4, and a bidentate coordination in 5 as confirmed by an X-ray analysis carried out with the palladium complex. The procedure has been extended for the synthesis of the carbosilane G1,[OCH2C(pz)3]4 (6) and the tetrametallic compound G1,[OCH2C(pz)3Mo(CO)3]4 (7) (G1 = Si(CH2CH2CH2Me2Si)4,). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Synthesis and Characterization of [OsCl2(=C=CHR)(PPh3)2] and Related ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2004Ting Bin Wen Abstract Treatment of [OsCl2(PPh3)3] with HC,CR (R = Ph, p -tolyl, CMe3) in the presence of HCl gives the corresponding trichloro(carbyne) complexes [OsCl3(,CCH2R)(PPh3)2] in good yields. The vinylidene complexes [OsCl2(=C=CHR)(PPh3)2] (R = Ph, p -tolyl, CMe3) are, in turn, prepared from the reactions of the carbyne complexes [OsCl3(,CCH2R)(PPh3)2] with NEt3. These new vinylidene complexes are hygroscopic and react with H2O to give (aqua)(vinylidene) complexes [OsCl2(H2O)(=C=CHR)(PPh3)2]. The structures of several of these new complexes have been determined by X-ray diffraction studies. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Synthesis, Characterization and Reactivity of New (,-Aminocarbyne)diruthenium Complexes Containing Alkynylimino LigandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 7 2004Luigi Busetto Abstract Addition of acetylides R,C,CLi [R, = Tol, Ph, Me3Si, nBu, C(Me)=CH2] to the diruthenium complexes [Ru2{,-CN(Me)(R)}(,-CO)(CO)(NCCMe3)(Cp)2]+ (R = Xy, 2a; Bz, 2b; Me, 2c) results in the formation of [Ru2{,-CN(Me)(R)}(,-CO)(CO){N(H)=C(CMe3)(C,CR,)}(Cp)2]+ (R = Xy, R, = Tol, 3a; R = Bz, R, = Tol, 3b; R = Me, R, = Tol, 3c; R = Xy, R, = Ph, 4a; R = Bz, R, = Ph, 4b; R = Me, R, = Ph, 4c; R = Bz R, = H, 5; R = Xy, R, = nBu, 6; R = Xy, R, = [C(Me)=CH2], 7), which contain an alkynylimino ligand, formed from addition of the acetylide to the Me3CCN ligand. Structural and spectroscopic studies show that all these complexes contain the two Cp ligands in a relative cis arrangement, whereas two isomers arise from the different orientation of the substituents on the bridging aminocarbyne ,-CN(Me)(R) when R , Me. Addition of secondary amines to 3,7 results in a stereo- and regioselective cis amination of the C,C triple bond to give the new complexes [Ru2{,-CN(Me)(R)}(,-CO)(CO){N(H)=C(CMe3)C(H)=C(NMe2)(Tol)}(Cp)2]+ (R = Xy, 8a; Bz, 8b; Me, 8c), [Ru2{,-CN(Me)(Xy)}(,-CO)(CO){N(H)=C(CMe3)C(H)=C(NC5H10)(Tol)}(Cp)2]+(9) and [Ru2{,-CN(Me)(Xy)}(,CO)(CO){N(H)=C(CMe3)C(H)=C(NMe2)C(Me)=CH2)}(Cp)2]+ (10) containing the hitherto unknown new imino-2-en-3-amine ligand. The solid-state structures of these products have been analyzed by X-ray analysis and, in solution, by NOE spectroscopic studies. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] (Neocuproin)zinc Thiolates: Attempts at Modeling Cobalamin-Independent Methionine SynthaseEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2004Jan Seebacher Abstract Several new complexes [(neo)Zn(SR)2] [neo = neocuproin (2,9-dimethylphenanthroline)] have been synthesized and structurally characterised. They react in a stepwise fashion with the alkylating agents CH3I and (CH3)2SO4 to afford the thioethers CH3SR and first the mixed complexes [(neo)Zn(SR)X] (X = I, CH3SO4) and then [(neo)ZnX2]. Similar alkylations occur with benzyl iodide, but not with trimethyl phosphate in nonpolar media. Under these conditions, thiolate exchange with [PPN]SR does not occur which indicates that the alkylations take place at the zinc-bound thiolates. In polar solvents (methanol, DMSO), thiolate exchange occurs readily, and at higher temperatures (CH3)3PO4 also acts as an alkylating agent which indicates that under these conditions free thiolate is available in solution. Qualitative kinetic data support the associative alkylation mechanism in nonpolar media and the change of mechanism in polar media. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Synthesis, Structure and Characterization of Two New Complexes [Cu2(C3H2O4)2(C4H4N2)]·2H2O and [Zn2(OH2)2(C3H2O4)2(C4H4N2)]EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 6 2003Xiutang Zhang Abstract Two new complexes with three-dimensional extended frameworks linked by pyrazine and malonate ligands, namely [Cu2(C3H2O4)2(C4H4N2)]·2H2O and [Zn2(OH2)2(C3H2O4)2(C4H4N2)], have been prepared and characterized by X-ray crystallography, IR, EPR and UV/Vis spectroscopy, their magnetic properties and electrical conductivity. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Synthesis, DNA-Binding and Photocleavage Studies of the Ruthenium(II) Complexes [Ru(phen)2(ppd)]2+ and [Ru(phen)(ppd)2]2+ (ppd=Pteridino[6,7- f],[1,10]phenanthroline-11,13(10H,12H)-dione, phen=1,10-Phenanthroline)HELVETICA CHIMICA ACTA, Issue 3 2008Feng Gao Abstract Two new complexes, [Ru(phen)2(ppd)]2+ (1) and [Ru(phen)(ppd)2]2+ (2) (ppd=pteridino[6,7- f],[1,10]phenanthroline-11,13(10H,12H)-dione, phen=1,10-phenanthroline) were synthesized and characterized by ES-MS, 1H-NMR spectroscopy, and elemental analysis. The intercalative DNA-binding properties of 1 and 2 were investigated by absorption-spectroscopy titration, luminescence-spectroscopy studies, thermal denaturation, and viscosity measurements. The theoretical aspects were further discussed by comparative studies of 1 and 2 by means of DFT calculations and molecular-orbital theory. Photoactivated cleavage of pBR322 DNA by the two complexes were also studied, and 2 was found to be a much better photocleavage reagent than 1. The mechanism studies revealed that singlet oxygen and the excited-states redox potentials of the complex may play an important role in the DNA photocleavage. [source] Theoretical study in [C2H4,Tl]+ and [C2H2,Tl]+ complexesINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 1 2007Fernando Mendizabal Abstract We studied the attraction between [C2Hn] and Tl(I) in the hypothetical [C2Hn,Tl]+ complexes (n = 2,4) using ab initio methodology. We found that the changes around the equilibrium distance C,Tl and in the interaction energies are sensitive to the electron correlation potential. We evaluated these effects using several levels of theory, including Hartree,Fock (HF), second-order Møller,Plesset (MP2), MP4, coupled cluster singles and doubles CCSD(T), and local density approximation augmented by nonlocal corrections for exchange and correlation due to Becke and Perdew (LDA/BP). The obtained interaction energies differences at the equilibrium distance Re (C,Tl) range from 33 and 46 kJ/mol at the different levels used. These results indicate that the interaction between olefinic systems and Tl(I) are a real minimum on the potential energy surfaces (PES). We can predict that these new complexes are viable for synthesizing. At long distances, the behavior of the [C2Hn],Tl+ interaction may be related mainly to charge-induced dipole and dispersion terms, both involving the individual properties of the olefinic ,-system and thallium ion. However, the charge-induced dipole term (R,4) is found as the principal contribution in the stability at long and short distances. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 [source] New Indenylidene-Schiff Base-Ruthenium Complexes for Cross-Metathesis and Ring-Closing MetathesisADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009Abstract We here report on the stability and catalytic activity of new indenylidene-Schiff base-ruthenium complexes 3a,f through representative cross-metathesis (CM) and ring-closing metathesis (RCM) reactions. Excellent activity of the new complexes was found for the two selected RCM reactions; prominent conversion was obtained compared to the commercial Hoveyda,Grubbs catalyst 2. Moreover, excellent results were obtained for a standard CM reaction. Higher conversions were achieved with one of the indenylidene catalysts compared with Hoveyda,Grubbs catalyst. Unexpectedly, an isomerization reaction was observed during the CM reaction of allylbenzene. To the best of our knowledge, isomerization reactions in this model CM reaction in closed systems have never been described using first generation catalysts, including the Hoveyda,Grubbs catalyst. The first model CM reactions as well as the RCM reactions have been monitored using 1H,NMR. The course of the CM reaction of 3-phenylprop-1-ene (8) and cis -1,4-diacetoxybut-2-ene (9) was monitored by GC. The isomerization reaction was studied by means of GC-mass spectrometry and in situ IR spectroscopy. All catalysts were structurally characterized by means of 1H, 13C, and 31P,NMR spectroscopy. [source] The role of the cyclometallated moiety on the second order nonlinear optical properties of cationic Ir(III) organometallic NLO-phoresPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue S1 2009Claudia Dragonetti Abstract The second order nonlinear optical (NLO) response of the new complexes [Ir(bzq)2(5-R-1,10-phen)][Y] (bzq = cyclometallated benzo[h]quinoline; phen = phenanthroline, R = Me, NO2; Y = PF6, C12H25SO3) and [Ir(bzq)2(4-R,7-R-1,10-phen)][Y] (R = Me, Ph) have been investigated experimentally by the Electric Field Induced Second Harmonic generation (EFISH) technique in CH2Cl2 solution and compared with that of [Ir(ppy)2(5-R-1,10-phen)][PF6] (ppy = cyclometallated 2-phenylpyridine, R = Me, NO2) and [Ir(ppy)2(4-R,7-R-1,10-phen)][PF6] (R = Me, Ph). It appeared that substitution of ppy with the more ,-delocalized bzq does not affect significantly the large second-order NLO response of this class of complexes. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The Interactorium: Visualising proteins, complexes and interaction networks in a virtual 3-D cellPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 23 2009Yose Y. Widjaja Abstract Here, we describe the Interactorium, a tool in which a Virtual Cell is used as the context for the seamless visualisation of the yeast protein interaction network, protein complexes and protein 3-D structures. The tool has been designed to display very complex networks of up to 40,000 proteins or 6000 multiprotein complexes and has a series of toolboxes and menus to allow real-time data manipulation and control the manner in which data are displayed. It incorporates new algorithms that reduce the complexity of the visualisation by the generation of putative new complexes from existing data and by the reduction of edges through the use of protein "twins" when they occur in multiple locations. Since the Interactorium permits multi-level viewing of the molecular biology of the cell, it is a considerable advance over existing approaches. We illustrate its use for Saccharomyces cerevisiae but note that it will also be useful for the analysis of data from simpler prokaryotes and higher eukaryotes, including humans. The Interactorium is available for download at http://www.interactorium.net. [source] Preparation and structures of a series of phosphorus-free Nickel(II) diamine complexes and their applications in hydrogenation of acetophenoneAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 9 2010Zilu Chen Abstract To develop economical and phosphorus-free catalysts for hydrogenation of ketones, three new complexes, [Ni(1R,2R -dpen)2(H2O)Cl]2Cl2· 2Et2O (1), [Ni(1R,2R -dpen)(phen)(CH3OH)2]Cl2·2CH3OH (2) and [Ni(1,8-dan)2(DMF)Cl]2Cl2· 3H2O (3), and three reported compounds, [Ni(opda)(phen)Cl2]·CH3OH (4), [Ni(opda)2Cl2] (5) and [Ni(1,2-dach)2]Cl2 (6), were prepared and the structures of new compounds were determined by single crystal X-ray diffraction analysis, in which 1R,2R -dpen, phen, 1,8-dan, opda and 1,2-dach denote 1R,2R -1,2-diphenylethylenediamine, 1,10-phenanthroline, 1,8-diaminonaphthalene, o -phenylenediamine and 1,2-diaminocyclohexane, respectively. The catalytic effects for hydrogenation of acetophenone of these compounds were tested. This revealed very poor or no catalytic effects of these complexes in transfer hydrogenation of acetophenone using isopropanol or HCOOHNEt3 as hydrogen source. However, they presented much better catalytic effects in ionic hydrogenation of acetophenone using H2 gas as hydrogen source with a dependence of the catalytic effects on the base used in the hydrogenation reactions. The complexes represent a kind of green hydrogenation catalyst, although the conversion in the hydrogenation reactions is not as high as expected. Copyright © 2010 John Wiley & Sons, Ltd. [source] Synthesis, characterization and single crystal structure determination of aluminum alkoxydisilanolates: precursors for silica,alumina compositeAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 6 2010Mostafa M. Amini Abstract Several novel aluminum alkoxydisilanolate complexes were prepared by reaction of triphenylsilanol with aluminum 2-methoxyethoxide, aluminum 2-ethoxyethoxide, aluminum sec -butoxide and aluminum iso -propoxide. All new complexes, [(Ph3SiO)2Al(OR)]2 [where R = CH2CH2OCH3 (1), CH2CH2OC2H5 (2), CH(CH3)CH2CH3 (3) and CH(CH3)2 (4)] were characterized by elemental analysis, mass spectrometry and infrared spectroscopy (IR), as well as 1H, 13C, 29Si and 27Al NMR spectroscopies. The solid-state structures of the representative compound 2 and 4 were also verified by single-crystal X-ray analyses. Complexes 2 and 4 are dimers having distorted trigonal bipyramidal and tetrahedral coordination at the aluminum center, respectively. The 27Al NMR spectrum of compound 2 showed that the solid-state structure of the complex was not retained in solution, and tetracoordinated aluminum was found in solution in contrast to the pentacoordinated geometry in the solid state. The hydrothermal treatment of 1 and 4 at 200 °C and the subsequent calcination at 1000 °C resulted in the formation of alumina,silica composite (4SiO2·Al2O3) with ,-alumina in the silica matrix. Copyright © 2010 John Wiley & Sons, Ltd. [source] Synthesis and characterization of transition metal complexes of thiophene-2-methylamine: X-ray crystal structure of palladium (II) and platinum (II) complexes and use of palladium(II) complexes as pre-catalyst in Heck and Suzuki cross-coupling reactionsAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2009Murat Aydemir Abstract The reactions of thiophene-2-(N -diphenylphosphino)methylamine, Ph2PNHCH2 -C4H3S, 1 and thiophene-2-[N,N -bis(diphenylphosphino)methylamine], (Ph2P)2NCH2 -C4H3S, 2, with MCl2(cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) or [Cu(CH3CN)4]PF6 yields the new complexes [M(Ph2PNHCH2 -C4H3S)2Cl2], M = Pd 1a, Pt 1b, [Cu(Ph2PNHCH2 -C4H3S)4]PF6, 1c, and [M(Ph2P)2NCH2 -C4H3S)Cl2], M = Pd 2a, Pt 2b, {Cu[(Ph2P)2NCH2 -C4H3S]2}PF6, 2c, respectively. The new compounds were isolated as analytically pure crystalline solids and characterized by 31P-, 13C-, 1H-NMR and IR spectroscopy and elemental analysis. Furthermore, the solid-state molecular structures of representative palladium and platinum complexes of bis(phosphine)amine, 2a and 2b, respectively, were determined using single crystal X-ray diffraction analysis. The palladium complexes were tested as potential catalysts in the Heck and Suzuki cross-coupling reactions. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||