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1.
S. Hussain I. U. Khan M. Akkurt S. Ahmad M. N. Tahir 《Russian Journal of Coordination Chemistry》2014,40(9):686-694
Two novel homobinuclear ytterbium(III) complexes, [Yb2(2AMB)6(H2O)4] · 2C2H6O (I) and Yb2(3AMB)6(H2O)4] · 3H2O (II) (2AMB = 2-aminobenzoic acid, 3AMB = 3-aminobenzoic acid) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis and X-ray crystallography (CIF files CCDC nos. 950103 (I), 921652 (II)). Complex I crystallizes in triclinic space group \(P\bar 1\) and complex II crystallizes in monoclinic space group P21/n. X-ray analysis shows that both complexes (I, II) have the dinuclear structure. The central Yb3+ ions in both complexes are eight-coordinated adopting distorted YbO8 dodecahedral geometry. Each Yb3+ ion is coordinated to two O atoms from bridging carboxylate, four O atoms from the chelating carboxylate ligands and two O atoms of water molecules. The crystal structure of I and II are stabilized by N-H…O, O-H…O, O-H…N, and C-H…O hydrogen bonds, C-H…π interactions and weak π-π stacking interactions. 相似文献
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Sudhir Burman Dixit N. Sathyanarayana Augostinos Anagnostopoulos 《Transition Metal Chemistry》1980,5(1):52-55
Summary Ferrous and ferric complexes of 2,4-dithiobiuret (Dtb) of the type Fe(Dtb)m Xn where m, n = 1-3, and X = CI–, Br–, I– and SO
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2–
, and a neutral Fe(Dtb-H)2 complex have been synthesized and characterised by elemental analyses, magnetic susceptibility, i.r., electronic and Mössbauer spectroscopic studies. From its i.r. spectrum Dtb was found to act as a S,S-coordinating bidentate chelate. The magnetic moment, electronic and Massbauer spectra are consistent with a low spin distorted octahedral structure for the ferric complexes and a high spin form for ferrous complexes. 相似文献
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Aleksanyan DV Kozlov VA Nelyubina YV Lyssenko KA Puntus LN Gutsul EI Shepel NE Vasil'ev AA Petrovskii PV Odinets IL 《Dalton transactions (Cambridge, England : 2003)》2011,40(7):1535-1546
Novel unsymmetrical SCS'-pincer ligands, 1-[PhNHC(S)]-3-[Ph(2)P(S)NH]-C(6)H(4) (3) and 1-[PhNHC(S)]-3-[Ph(2)P(S)O]C(6)H(4) (7), bearing a thiocarbamoyl moiety in combination with thiophosphorylamino- and thiophosphoryloxy-donating groups, respectively, were obtained via thiophosphorylation of 3-amino- and 3-hydroxy-benzoic acid (thio)anilides 1 and 6. Direct cyclometallation of the central benzene ring in the ligands 3 and 7 in reaction with (PhCN)(2)MCl(2) (M = Pd, Pt) as a metal precursor afforded κ(3)-SCS'-hybrid pincer complexes 8, 9 with 5- and 6-membered fused metallacycles in good to high yields (67-95%). The complexes 8 and 9 were characterized by multinuclear NMR ((31)P, (1)H, (13)C) and IR spectroscopy as well as single-crystal X-ray crystallography. Palladium complexes 8a and 9a were shown to be active catalysts for the Suzuki-Miyaura cross-coupling reaction. In the solid state the ligands 3 and 7 as well as their Pt(II) and Pd(II) complexes 8 and 9 are luminescent at 300 K. The emission of the complexes has the different origin depending on the metal nature. 相似文献
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Bis(tertiaryphosphine/arsine oxides), Ph2E(O) (CH2)nE(O)Ph2 react with iron(II) iodide and iron(II) tetracarbonyliodide forming com 相似文献
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Séverine Roué 《Journal of organometallic chemistry》2005,690(3):594-604
The synthesis of the new complexes Cp*(dppe)FeCC2,5-C4H2SR (Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl; dppe = 1,2-bis(diphenylphosphino)ethane; 2a, R = CCH; 2b, R = CCSi(CH3)3; 2c, R = CCSi(CH(CH3)2)3; 3a, R = CC2,5-C4H2SCCH; 3c, R = CC2,5-C4H2SCCSi(CH(CH3)2)3) is described. The 13C NMR and FTIR spectroscopic data indicate that the π-back donation from the metal to the carbon rich ligand increases with the size of the organic π-electron systems. The new complexes were also analyzed by CV and the chemical oxidation of 2a and 3c was carried out using 1 equiv of [Cp2Fe][PF6]. The corresponding complexes 2a[PF6] and 3c[PF6] are thermally stable, but 2a[PF6] was too reactive to be isolated as a pure compound. The spectroscopic data revealed that the coordination of large organic π-electron systems to the iron nucleus produces only a weak increase of the carbon character of the SOMO for these new organoiron(III) derivatives. 相似文献
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Yasuo Kikuchi Naoji Kubota Hirofumi Fukuma Hiroshi Mitsuishi 《Macromolecular rapid communications》1996,17(2):131-136
Glycol chitosan (GC) and methyl glycol chitosan (MGC) were separately reacted with poly(potassium vinyl sulfate) (PVSK) in the presence of iron(III) hydroxide sulfate (IHS) to form water-insoluble macromolecular complexes (MC's). The chemical compositions and properties of MC's obtained were compared with each other. The solubility of MC in the MGC-IHS-PVSK system was lower than that in the GC-IHS-PVSK system, and it was suggested that MGC contributes to the properties of MC. 相似文献
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Tanase S Marqués Gallego P Bouwman E Long GJ Rebbouh L Grandjean F de Gelder R Mutikainen I Turpeinen U Reedijk J 《Dalton transactions (Cambridge, England : 2003)》2006,(13):1675-1684
The synthesis and characterization of two new iron(II) complexes, [Fe(pca)2(py)2].py (1) and {[Fe(pca)2(H2O)].H2O}n (2) and one new iron(III) complex, Na2{[Fe(pca)()]2O}.2H2O.2CH3CN (3) (pca- stands for 2-pyrazinecarboxylate), are reported. Complex 1 is obtained from the reaction of iron powder with 2-pyrazinecarboxylic acid. The reaction of Fe(ClO4)3.10H2O with Hpca in the presence of 3 equiv. of Bu4NOH yields 2, whereas the presence of NaOH yields 3. The molecular structure of 1 contains an iron(II) ion with a pseudo-octahedral environment resulting from the coordination of two pca- ligands in a bidentate chelating fashion and two pyridine molecules; pi-pi stacking interactions between pyridine and pyrazine rings lead to a one-dimensional chain. Complex 2 is an iron(II) coordination polymer with an infinite zig-zag motif and an Fe...Fe separation of 7.1 A. In 2, the pi-pi stacking interactions involving the pyrazine rings and the strong hydrogen bonds between the coordinated water molecule and the carboxylate oxygens of two pca- ligands result in a three-dimensional network structure. Complex 3 consists of an anionic micro-oxo-bridged diiron(III) core with two crystallographically distinct iron(iii) ions; the negative charge is compensated by two sodium cations. Complex 3 is assembled in a three dimensional network structure through coordination of Na(I) and hydrogen bond interactions. Temperature dependent magnetic susceptibility and M?ssbauer spectroscopic studies indicate that 1 and 2 have similar magnetic properties. Both complexes are paramagnetic above 12 K, whereas antiferromagnetic ordering is observed below 12 K. The magnetic properties of reveal strong intramolecular antiferromagnetic interactions between the two iron(III) ions with a J value of -221 cm(-1); no long range intermolecular magnetic coupling is observed between 295 and 4.2 K. 相似文献
10.
Mostafa Kamal Hassan 《Transition Metal Chemistry》1991,16(6):618-621
Summary Mixed ligand complexes of general formula [UO2L1L2-(H2O)n], where L1 iso-hydroxy-,o-mercapto- oro-aminobenzoic acid and L2 is glycine, L-alanine, or L-valine, have been prepared and characterized. The uranium atom in these complexes is 6- or 8-coordinate. Both acid ligands are bidentate, bonding through the ionized –COO–– group and either O, N or S atoms. 相似文献
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Interaction of iron ions with a six-amino acid model of the ferroxidase center of human H chain ferritin has been examined in density functional theory calculations. The model, based on experimental studies of oxidation of Fe2+ at the center, consists of Glu27, Glu62, His65, Glu107, Gln141, and Ala144. Reasonable structures are obtained in a survey of types of iron complexes inferred to occur in the ferroxidase reaction. Structures of complexes of the model center with one and two Fe2+ ions, with diiron(III) bridged by peroxide and bridged by oxide-peroxide combinations, have been optimized. Calculations on diiron(III) complexes confirm that stable peroxide-bridged complexes can form and that the Fe-Fe distance in at least one is consistent with the experimental Fe-Fe distance observed in the blue peroxodiferric complex of ferritin. 相似文献
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Heimei Yuki Yoshio Okamoto Yutaka Taketani Tetsuo Tsubota Yoshizo Marubayashi 《Journal of polymer science. Part A, Polymer chemistry》1978,16(9):2237-2251
Poly(α-isobutyl-L -aspartate) was prepared by the polycondensation reaction of p-nitrophenyl ester of α-isobutyl-L -aspartate and the conformation of the poly(β-amino acid) was investigated by X-ray diffraction, polarized infrared, circular dichroism (CD), optical rotatory dispersion (ORD), and NMR spectroscopy. α-Isobutyl β-p-nitrophenyl-L -aspartate hydrochloride and hydrobromide were used as monomers and dimethylformamide, chloroform, and chlorobenzene, as solvents. A high-molecular-weight polymer with [η] 1.0 dl/g (dichloroacetic acid, 25°C) was formed in the polymerization of the hydrochloride in chloroform at 25°C. The X-ray diagram and polarized infrared spectrum of the stretched polymer film obtained from a chloroform solution suggested a cross-β-form as the most probable structure in the solid state. The CD spectra of the polymer in a 2,2,2-trifluoroethanol (TFE) solution and its film cast from the solution showed a peak at 205 nm and a trough at 190 nm which were assigned to a β-structure. The polymer was associated in chloroform. The NMR and ORD spectra in chloroform were similar to those in TFE, which suggests that the polymer also exists in the β-structure in chloroform. The addition of small amounts of dichloroacetic acid and sulfuric acid to chloroform and TFE solutions, respectively, destroyed the β-structure. A random copolymer of α-isobutyl-L -aspartate with β-alanine was also prepared by polycondensation reaction. The copolymer apparently did not form an ordered structure in the solid state or in solution. 相似文献
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Munenori Sakamoto Yoshimitsu Kuroyanagi Ryuichi Sakamoto 《Journal of polymer science. Part A, Polymer chemistry》1978,16(8):2001-2017
A number of multi-N?-poly(γ-benzyl-L -glutamyl)copoly(L -lysine γ-methyl-L -glutamate)s with branches having various degrees of polymerization and with various intervals of the grafting sites in the core molecule were prepared in N,N-dimethylformamide containing dimethyl sulfoxide by the reaction of N-carboxy anhydride of γ-benzyl L -glutamate with random copoly(L -lysine γ-methyl-L -glutamate)s of different composition with various anhydride-initiator ratios. The relationship between the intrinsic viscosity measured in a coil solvent, dichloroacetic acid (DCA), and the number-average molecular weight determined by osmometry was found to be expressed by the Mark–Houwink–Sakurada equation for the multichain copoly(α-amino acid)s which were made from the same polymeric initiator. The observed α values of the multichain copoly(α-amino acid)s in the equation were lower than that of linear poly(γ-benzyl-L -glutamate). The solvent induced helix–coil transition of the multichain copolymer was investigated in the chloroform?DCA system by the ORD technique. Two kinds of transition regions were clearly distinguished: The α-helices of the core molecules underwent the transition at lower DCA concentration and those of the branch chains at higher DCA concentration. The reduced viscosity of the multichain copoly-(α-amino acid) increased slightly between the two transition regions, in contrast to the large decrease in the reduced viscosity of linear poly(γ-benzyl-L -glutamate) during the helix–coil transition. 相似文献
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Dean RK Fowler CI Hasan K Kerman K Kwong P Trudel S Leznoff DB Kraatz HB Dawe LN Kozak CM 《Dalton transactions (Cambridge, England : 2003)》2012,41(16):4806-4816
Eight new iron(III) amine-bis(phenolate) complexes are reported. The reaction of anhydrous FeX(3) salts (where X = Cl or Br) with the diprotonated tripodal tetradentate ligands 2-tetrahydrofurfurylamino-N,N-bis(2-methylene-4,6-di-tert-butylphenol), H(2)L1, 2-tetrahydrofurfurylamino-N,N-bis(2-methylene-4-methyl-6-tert-butylphenol), H(2)L2, and 2-methoxyethylamino-N,N-bis(2-methylene-4,6-di-tert-butylphenol), H(2)L3, 2-methoxyethylamino-N,N-bis(2-methylene-4-methyl-6-tert-butylphenol), H(2)L4 produces the trigonal bipyramidal iron(III) complexes, L1FeCl (1a), L1FeBr (1b), L2FeCl (2a), L2FeBr (2b), L3FeCl (3a), L3FeBr (3b), L4FeCl (4a), and L4FeBr (4b). All complexes have been characterized using electronic absorption spectroscopy, cyclic voltammetry and room temperature magnetic measurements. Variable temperature magnetic data were acquired for complexes 2b, 3a and 4b. Variable temperature M?ssbauer spectra were obtained for 2b, 3a and 4b. Single crystal X-ray molecular structures have been determined for proligand H(2)L4 and complexes 1b, 2b, and 4b. 相似文献
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I. Labádi G. Liptay A. Horváth L. Korecz S. Papp K. Burger 《Journal of Thermal Analysis and Calorimetry》1987,32(5):1575-1584
Nine iron(II) ethylene glycol sulphate complexes were prepared. Their compositions were determined by standard analytical methods. They were characterized by means of temperature-dependent magnetic susceptibility and Mössbauer spectroscopic measurements. On the basis of the patterns of their thermal decompositions, the complexes could be classified into three groups.
Zusammenfassung Neun Eisen(II)-ethylenglykol-sulfat-Komplexe wurden dargestellt. Die Zusammensetzung dieser Komplexe wurde nach analytischen Standardmethoden bestimmt. Die Verbindungen wurden durch Messungen der temperaturabhängigen magnetischen Susceptibilität sowie mittels Mössbauer-Spektroskopie charakterisiert. Nach dem Verhalten bei der thermischen Zersetzung konnten diese Komplexe in drei Gruppen klassifiziert werden.
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Journal of Thermal Analysis and Calorimetry - Solid complexes of RE(NO3)3(Sm, Tb) and aspartic acid were prepared for the first time in aqueous solution. Based on chemical analysis, elemental... 相似文献
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Valeriu Mereacre Denis Prodius Ayuk M. Ako Sergiu Shova Constantin Turta Klaus Wurst Peter Jaitner Annie K. Powell 《Polyhedron》2009,28(16):3551-3555
The reaction of [Fe3EuO2(O2CCCl3)8(H2O)(THF)3] or [Fe2CaO(O2CCCl3)6(THF)4] and [Fe3O(O2CCMe3)6(H2O)3]NO3 with 1,1′-ferrocenedicarboxylic acid (fcdcH2) yielded penta- and hepta-nuclear [Fe4O2(O2CCCl3)6(fcdc)(THF)2(H2O)2] and [Fe6O2(OH)2(O2CCMe3)10(fcdc)(H2O)2], respectively, which are the first X-ray structurally characterized clusters comprising Fe(III) and the ferrocenedicarboxylic organometallic ligand. Variable-temperature solid-state magnetic susceptibility measurements in the temperature range 1.8–300 K were carried out, and for both complexes a predominantly antiferromagnetic exchange interaction between the metal centres was observed. Mössbauer investigations show the presence of different environments for the Fe(III) atoms and confirm that no electron-transfer from Fe(II) of the ferrocene unit to Fe(III) of the central core occurs. 相似文献
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Summary The formation equilibria of the binary and ternary complexes of CuII withN-(acetamido)-iminodiacetic acid (ADA) and amino acids or their esters were investigated potentiometrically. The chelation mode was ascertained by conductivity measurements. The kinetics of the base hydrolysis of amino acid esters in the presence of the copper(II)-ADA complex were studied. The rate and catalysis constants were estimated. 相似文献