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1.
Wolfgang A. Herrmann Cornelia Weber Manfred L. Ziegler Orhan Serhadli 《Journal of organometallic chemistry》1985,297(2):245-254
The diazoolefines of composition N2CCR2 (R/R = CH3/CH3 and(-CH2-)5) are suitable precursors of the corresponding vinylidene ligands CCR2. Thus, treatment of the RhRh complex [(η5-C5Me5)Rh(μ-CO)]2 (1) with the N-nitrosourethanes 2a and 2b, resp., in the presence of lithium t-butoxide yields the otherwise inaccessible μ-vinylidene complexes (μ-CCR2)[(η5-C5Me5)Rh(CO)]2 (R = CH3 (3a), R,R = (-CH2-)5 (3b)). The analogous cobalt compound (μ-CCMe2)[(η5-C5Me5)Co(CO)]2 (5a) is obtained similarly. This procedure extends the well-documented diazoalkane method for the synthesis of μ-alkylidene complexes to the less stable diazoalkenes. A single-crystal X-ray diffraction study of the dimethylvinylidene derivative 3a shows the CMe2 ligand to adopt an almost symmetrically metal-bridging position (d(RhC) 197.8(1) and 204.3(1) pm), with a rhodium-rhodium single bond completing a three-membered Rh2C-metallacycle (d(RhRh) 268.4(0) pm) analogous with cyclopropane. 相似文献
2.
Orhan Acar A. Rehber Türker Ziya Kl? 《Fresenius' Journal of Analytical Chemistry》1998,360(6):645-649
A comparative and systematic study has been carried out of the effects of palladium and molybdenum containing chemical modifiers,
such as Pd + Rh, Pd + Pt, Pd + Ru, Pd + Rh + Pt, Pd + Rh + Ru, Mo + Pd, Mo + Rh, Mo + Ru and Mo + Pt and additionally tartaric
acid (TA) as a reducing agent together with mixed modifiers for the thermal stabilization of Bi, In and Pb in a Zeeman electrothermal
atomic absorption spectrometer (ETAAS). The effect of the mass ratios of the mixed modifier components on the maximum pretreatment
temperature for the analytes has been determined. The modifier mixtures of Pd + Rh + Pt, Mo + Pd + TA and Mo + Pt + TA were
found to be especially powerful for the determination of Bi, In and Pb. These mixed modifiers could increase the ashing temperatures
of the analytes up to 1250–1400° C. They were applied to the determination of Bi and Pb in dissolved geological reference
samples and accuracy and precision of the method were thereby enhanced. The percent relative error was decreased from 20.0
to 0.4 for Bi and from 10.5 to 0.3 for Pb, depending on the sample type.
Received: 9 May 1997 / Revised: 19 August 1997 / Accepted: 20 August 1997 相似文献
3.
4.
Raif Kurtaran Cengiz Arici Kaan C. Emregül Diner Ülkü Orhan Atakol Mustafa Tatekin 《无机化学与普通化学杂志》2003,629(9):1617-1621
A homo‐dinuclear NiII complex was prepared from 2, 6‐bis(3, 5‐dimethylpyrazolyl)pyridine (Me4‐bpp) and azide ions in nonaqueous media. It was characterized by single crystal X‐ray structural analysis, IR spectroscopy, and elemental analysis. In addition, the electrochemical properties of the compound were determined with cyclic voltammetry in DMF. The title compound crystallizes in the P21/n monoclinic space group, with unit cell parameters a = 8.978(1), b = 12.459(1), c = 17.764(1) Å, ß =100.603(3)°, V = 1953.0(3) Å3, Z = 2. The Ni2+ ion has a distorted octahedral environment involving three nitrogen atoms of the Me4‐bpp ligand, two nitrogen atoms from the bridged azide group, and one nitrogen atom from the terminal azide group. The Ni···Ni distance is 3.273(5) Å. 相似文献
5.
The novel bis(cyclohexylaminium) cyclohexylaminebis(orotate–N,O)cuprate(II) dihydrate, (C6H15N)2[Cu(C5H2N2O4)2(C6H14N)] · 2H2O, has been prepared and characterized by elemental analysis, magnetic measurements, FT-IR and UV–Vis spectroscopy, thermal analysis and X-ray diffraction. The Cu(II) complex crystallizes in the monoclinic space group P21/c. The copper atom in the five-coordinated (chaH)2[Cu(HOr–N,O)2(cha)] · 2H2O is chelated by a deprotonated pyrimidine nitrogen atom and carboxylate oxygen atom as a bis(bidentate) ligand and the cyclohexylamine ligand completes the square-pyramidal coordination. The thermal decomposition of the complex has been predicted by the help of thermal analysis (TG, DTG and DTA). 相似文献
6.
Osman Dayan Muharrem Diner Bekir etinkaya Namk
zdemir Orhan Büyükgüngr 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(8):m346-m348
The title complex, di‐μ‐chloro‐bis[chloro(η6‐p‐cymene)ruthenium(II)]–9H‐carbazole (1/2), [Ru2Cl4(C10H14)2]·2C12H9N, is composed of one [RuCl2(η6‐p‐cymene)]2 and two 9H‐carbazole molecules. There are one‐half of a dinuclear complex and one 9H‐carbazole molecule per asymmetric unit. In the dinuclear complex, each of the two crystallographically equivalent Ru atoms is in a pseudo‐tetrahedral environment, coordinated by a terminal Cl atom, two bridging Cl atoms and the aromatic hydrocarbon, which is linked in a η6 manner; the Ru⋯Ru separation is 3.688 (3) Å. The title complex has a crystallographic centre of symmetry located at the mid‐point of the Ru⋯Ru line. Intermolecular N—H⋯Cl and π–π stacking interactions are observed. These interactions form a four‐pointed star‐shaped ring and one‐dimensional linear chains of edge‐fused rings running parallel to the [100] direction, which stabilize the crystal packing. 相似文献
7.
Atta-ur-Rahman Nasim S Baig I Sener B Orhan I Ayanoglu F Choudhary MI 《Natural product research》2004,18(5):465-471
Two new isoflavones 1 and 2 along with eleven known compounds 3-13, have been isolated for the first time from the rhizomes of Iris soforana. The structures of these compounds were determined on the basis of spectroscopic methods and found to be 5,3'-dihydroxy-4'-methoxy-6,7-methylenedioxyisoflavone (1) (Soforanarin A), and 5,7,5'-trimethoxy-6,3',4'-trihydroxyisoflavone (2) (Soforanarin B). 相似文献
8.
Orhan Acar 《Mikrochimica acta》2005,151(1-2):53-58
Lead, Cr, Mn and Zn in slurries of botanic and biological samples were determined by electrothermal atomic absorption spectrometry (ETAAS) using W, Ir, NH4H2PO4, W and NH4H2PO4, Ir and NH4H2PO4, W and Ir, and W + Ir + NH4H2PO4 chemical modifiers in an 0.2% (v/v) Triton X-100 plus 0.2% (v/v) nitric acid mixture. Zeeman effect background correction was performed and platforms inserted into graphite tubes were used. Comprehensive comparative studies were carried out with respect to pyrolysis and atomization temperatures, atomization and background absorption profiles, characteristic masses, detection limits and accuracy of the determinations in the presence and absence of modifiers. The mixture of W + Ir + NH4H2PO4 was found to be preferable for the determination of Pb, Cr, Mn and Zn in slurry samples. The pyrolysis temperatures of the analytes were increased up to 1250 °C for Pb, 1000 °C for Zn, 1400 °C for Cr and Mn by using W + Ir + NH4H2PO4 with an 0.2% (v/v) Triton X-100 plus 0.2% (v/v) nitric acid mixture used as diluent solution. The optimum masses of the mixed modifier components were found to be 20 µg W + 4 µg Ir + 50 µg NH4H2PO4. The characteristic masses of Pb, Cr, Mn and Zn obtained are 16.3, 5.6, 0.1 and 1.1 pg, respectively. The detection limits of Pb, Cr, Mn and Zn based on integrated absorbance for 0.5% (m v−1) slurries were found to be 0.14, 0.06, 0.02 and 0.01 µg g−1, respectively. The slurries of botanic and biological certified and standard reference materials were analyzed with and without the modifiers. Depending on the sample type, the percent recoveries increased from 63 up to 104% for analytes when using the proposed modifier mixture. 相似文献
9.
Sevim Hamamci Veysel T. Yilmaz Orhan Büyükgüngr 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(1):m1-m3
Crystallization of the title compound, di‐μ‐pyridazine‐1κ2N:2κ2N′‐bis[(2,3‐dihydro‐3‐oxobenzisosulfonazolato‐κN)silver(I)], [Ag2(C7H4NO3S)2(C4H4N2)2], from acetonitrile yields both monoclinic, (I), and triclinic, (II), polymorphs. In both forms, the silver(I) ions have a slightly distorted trigonal AgN3 coordination geometry and are doubly bridged by two neutral pyridazine (pydz) ligands, generating a centrosymmetric dimeric structure. The saccharinate (sac) ligands are N‐coordinated. The dihedral angles between the sac and pydz rings are 8.43 (7) and 7.94 (8)° in (I) and (II), respectively, suggesting that the dimeric molecule is nearly flat. The bond geometry is similar in both polymorphs. In (I), the dimers interact with each other via aromatic πsac–πpydz stacking interactions, forming two‐dimensional layers, which are further crosslinked by weak C—H⋯O interactions. Compound (II) exhibits similar C—H⋯O and π–π interactions, but additional C—H⋯π and π⋯Ag interactions help to stabilize the packing of the dimers. 相似文献
10.
The beta dose response and Optically Stimulated Luminescence (OSL) signal stability characteristics of human tooth enamel deproteinated by hydrazine reagent under blue photon stimulation are reported. Removal of the protein organic component of tooth enamel resulted in a higher OSL sensitivity and slower fading of OSL signals. The effect of chemical sample preparation on the enamel sample sensitivity is discussed and further steps to make this deproteinization treatment suitable for in vitro dose reconstruction studies are suggested. 相似文献