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Octahedral Structure (octahedral + structure)
Selected AbstractsOptical absorption and EPR spectral studies of vauqueliniteCRYSTAL RESEARCH AND TECHNOLOGY, Issue 8 2006K. Nagamuni Reddy Abstract Vauquelinite - a mineral - was investigated by EPR, NIR and optical spectroscopic techniques. EPR studies on powder sample confirm the presence of Cu(II) and Fe(III) impurity in the mineral. Optical absorption spectrum also indicates that Cu(II) impurity is present in rhombically distorted octahedral structure and Fe(III) in octahedral structure. NIR results are due to water fundamentals and phosphate combination tone. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Crystal structure of a ternary mononuclear copper (II) complex: 4-chloro-3-methyl-6[(N-2-picolyl)-1,-iminomethyl]phenolato copper(II)perchlorateCRYSTAL RESEARCH AND TECHNOLOGY, Issue 5 2006S. M. Malathy Sony Abstract The complex crystallizes in monoclinic space group P21/n with unit cell parameters a = 7.295(4), b = 19.627(5), c = 12.770(4) Å, , = 101.25(4)º, V = 1793.2(12) Å3, Z = 4, , = 1.684 Mg/m3 at T = 293(2)K. The structure was solved by Patterson method and refined by full-matrix least-squares procedures to final R = 0.0387 using 2906 observed reflections. The asymmetric unit of the complex contains a mononuclear tridentate ligand, a perchlorate group and a methanol molecule. The compound crystallizes as parallel layers of polymeric complex bridged through perchloarate groups. The molecular CuN2OO,O,,2 chromophore involves an elongated rhombic octahedral structure and the Cu-ligand bond shows greater disparity. The five-membered chelate ring and the pyridine ring lie in the same plane while the six membered chelate ring assumes sofa conformation. A strong O-H,O inter molecular interaction plays a key role in the formation of dimer along b-axis. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Spectroscopic and crystal structure analysis of diamminebis(2,4,6-triiodophenolato-O) copper(II)CRYSTAL RESEARCH AND TECHNOLOGY, Issue 5 2006Gülsün Göka Abstract The crystal structure of [Cu(C6H2I3O)2(NH3)2] (CCDC 238896) has been determined by x-ray diffraction. This monomeric centrosymmetric Cu(II) complex crystallizes in the monoclinic system. The CuO2N2 coordination sphere is trans -planar, [Cu,O: 1.943(5) Å and Cu-N: 1.972(7)] with the fifth and sixth coordination sites occupied by I atoms from the phenoxide ions [Cu,I1: 3.3552(8) Å] to form a tetragonally elongated octahedral structure for CuO2N2I2 coordination. The complex molecules hold together in a one dimensional chain true [100] direction by intermolecular hydrogen bonds. Differantial scanning calorimeter, FTIR and magnetic susceptibility measurements were also performed in order to identify the title complex. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Coordination Chemistry of N,N,N,,N, -Tetraethylpyridine-2,6-dithiocarboxamide (S -dept) , X-ray Crystal Structures and Magnetic Properties of [Co(S -dept)X2] (X = Br, I, and NCS)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 19 2005Ramesh Kapoor Abstract Mononuclear cobalt(II) complexes [Co(S -dept)X2] [X = Br (1), I (2) and NCS (3)] were synthesized using N,N,N,,N, -tetraethylpyridine-2,6-dithiocarboxamide (S -dept), and characterised by conductivity, spectral and single-crystal X-ray diffraction studies. These studies reveal that the compounds consist of discrete monomeric molecules in which the cobalt atoms are five-coordinate in an environment that is best described as being distorted square-pyramidal. In dimethylformamide the iodo complex shows significant ionic dissociation (1:1 electrolyte) and its crystal field absorption spectrum is interpretable in terms of an octahedral structure [Co(S -dept)(DMF)2I]+. The temperature dependence of the magnetic susceptibility data is indicative of a high-spin compound with an important zero-field splitting. The best fitwas obtained with |D| = 20.5 cm,1 and g = 2.53 for 1, |D| = 14.2 cm,1 and g = 2.38 for 2 and |D| = 17.7 cm,1 and g = 2.35 for 3. The X-band EPR spectra at low temperature is also characteristic of an S = 3/2 state with important zero-field splitting. The most important band appears at low fields (ca. 1200 G). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Synthesis, characterization, electrochemical, catalytic and antimicrobial activity studies of hydrazone Schiff base ruthenium(II) complexesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 4 2010N. Thilagavathi Abstract Four tridentate O, N, O donor Schiff base ligands were prepared by the reaction of substituted benzhydrazide and appropriate salicylaldehyde. The complexes of these ligands were synthesized by refluxing the ligands with ruthenium(II) starting complexes of the formula [RuHCl(CO)(EPh3)2B] in benzene, where E = P or As; B = PPh3 or AsPh3 or pyridine. The newly synthesized complexes were characterized by elemental, spectral (FT-IR, UV and NMR) and electrochemical data. On the basis of the above studies, an octahedral structure has been proposed for all the complexes. The catalytic efficiency of the complexes in aryl,aryl couplings and oxidation of alcohols was examined and their inhibition activity against the growth of the micro-organisms was also examined. Copyright © 2009 John Wiley & Sons, Ltd. [source] Synthesis, characterization and catalytic studies of ruthenium(II) chalconate complexesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 2 2009M. Muthukumar Abstract Stable ruthenium(II) carbonyl complexes of the type [RuCl(CO)(EPh3)(B)(L)] (E = P or As; B = PPh3, AsPh3 or Py; L = 2,-hydroxychalcones) were synthesized from the reaction of [RuHCl(CO)(EPh3)2(B)] (E = P or As; B = PPh3, AsPh3 or Py) with 2,-hydroxychalcones in benzene under reflux. The new complexes were characterized by analytical and spectroscopic (IR, electronic 1H, 31P and 13C NMR) data. They were assigned an octahedral structure. The complexes exhibited catalytic activity for the oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of N -methylmorpholine- N -oxide (NMO) as co-oxidant and were also found to be efficient transfer hydrogenation catalysts. Copyright © 2008 John Wiley & Sons, Ltd. [source] Synthesis, spectral and antimicrobial studies of diorganotin(IV)3(2,-hydroxyphenyl)-5-(4-substituted phenyl) pyrazolinatesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 10 2006U. N. Tripathi Abstract Diorganotin(IV) dipyrazolinates of the type R2Sn(C15H12N2OX)2 [where C15H12N2OX = 3(2,-Hydroxyphenyl)-5(4-X-phenyl)pyrazoline {where X = H (a); CH3 (b); OCH3 (c); Cl (d) and R = Me, Prn and Ph}] have been synthesized by the reaction of R2SnCl2 with sodium salt of pyrazolines in 1:2 molar ratio, in anhydrous benzene. These newly synthesized derivatives have been characterized by elemental analysis (C, H, N, Cl and Sn), molecular weight measurement as well as spectral [IR and multinuclear NMR (1H, 13C and 119Sn)] studies. The bidentate behaviour of the pyrazoline ligands was confirmed by IR, 1H and 13C NMR spectral data. A distorted trans -octahedral structure around tin(IV) atom for R2Sn(C15H12N2OX)2 has been suggested. The free pyrazoline and diorganotin(IV) dipyrazolinates have also been screened for their antibacterial and antifungal activities. Some diorganotin(IV) dipyrazolinates exhibit higher antibacterial and antifungal effect than free ligand and some of the antibiotics. Copyright © 2006 John Wiley & Sons, Ltd. [source] Chiral Fluorous Dialkoxy-Diamino Zirconium Complexes: Synthesis and Use in Stereospecific Polymerization of 1-HexeneCHEMISTRY - A EUROPEAN JOURNAL, Issue 3 2007Evgueni Kirillov Dr. Abstract New catalysts for the isospecific polymerization of 1-hexene based on cationic zirconium complexes incorporating the tetradentate fluorous dialkoxy-diamino ligands [OC(CF3)2CH2N(Me)(CH2)2N(Me)CH2C(CF3)2O]2, [(ON2NO)2,] and [OC(CF3)2CH2N(Me)(1R,2R -C6H10)N(Me)CH2C(CF3)2O]2, [(ONCyNO)2,] have been developed. The chiral fluorous diamino-diol [(ONCyNO)H2, 2] was prepared by ring-opening of the fluorinated oxirane (CF3)2COCH2 with (R,R)- N,N, -dimethyl-1,2-cyclohexanediamine. Proligand 2 reacts cleanly with [Zr(CH2Ph)4] and [Ti(OiPr)4] precursors to give the corresponding dialkoxy complexes [Zr(CH2Ph)2(ONCyNO)] (3) and [Ti(OiPr)2(ONCyNO)] (4), respectively. An X-ray diffraction study revealed that 3 crystallizes as a 1:1 mixture of two diastereomers (,- 3 and ,- 3), both of which adopt a distorted octahedral structure with trans -O, cis -N, and cis -CH2Ph ligands. The two diastereomers ,- 3 and ,- 3 adopt a C2 -symmetric structure in toluene solution, as established by NMR spectroscopy. Cationic complexes [Zr(CH2Ph)(ON2NO)(THF)n]+ (n=0, anion=[B(C6F5)4],, 5; n=1, anion=[PhCH2B(C6F5)3],, 6) and [Zr(CH2Ph)(ONCyNO)(THF)]+[PhCH2B(C6F5)3], (7) were generated from the neutral parent precursors [Zr(CH2Ph)2(ON2NO)] (H) and [Zr(CH2Ph)2(ONCyNO)] (3), and their possible structures were determined on the basis of 1H, 19F, and 13C NMR spectroscopy and DFT methods. The neutral zirconium complexes H and 3 (,- 3/,- 3 mixture), when activated with B(C6F5)3 or [Ph3C]+[B(C6F5)4],, catalyze the polymerization of 1-hexene with overall activities of up to 4500,kg,PH,mol,Zr,1,h,1, to yield isotactic-enriched (up to 74,% mmmm) polymers with low-to-moderate molecular weights (Mw=4800,47,200) and monodisperse molecular-weight distributions (Mw/Mn=1.17,1.79). [source] | ||||||||||