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61.
《Journal of Saudi Chemical Society》2014,18(6):762-773
Oxygen absorption–desorption processes for square planar Mn(II), Co(II) and Mn(II) complexes of tetradentate Schiff base ligands in DMF and chloroform solvents were investigated. The tetradentate Schiff base ligands were obtained by condensation reaction of ethylenediamine with salcyldehyde, o-hydroxyacetophenone or acetylacetone in the molar ratio 1:2. The square planar complexes were prepared by the reaction of the Schiff base ligands with Mn(II) acetate, Co(II) nitrate and Ni(II) nitrate in dry ethanol under nitrogen atmosphere. The sorption processes were undertaken in the presence and absence of (pyridine) axial-base in 1:1 M ratio of (pyridine:metal(II) complexes). Complexes in DMF indicate significant oxygen affinity than in chloroform solvent. Cobalt(II) complexes showed significant sorption processes compared to Mn(II) and Ni(II) complexes. The presence of pyridine axial base clearly increases oxygen affinity. 相似文献
62.
《Journal of Coordination Chemistry》2012,65(2):91-99
Abstract The crystal structure of tetrakis(N,N′-dimethylthiourea)nickel(II) bromide dihydrate has been determined by three-dimensional x-ray diffraction from 1916 counter-data reflections collected at room temperature. The structure consists of Ni[SC(NH)2(CH3)2]2+ 4 molecular ions, Br? ions and waters of hydration. The nickel is located on a center of symmetry and is coordinated to four sulfur atoms in a square planar configuration. The waters of hydration and the bromide ions are involved in hydrogen bonding to the N,N′-dimethylthiourea (dmtu) groups. The orientation of the dmtu groups is such that two bond through the sulfur sp2 orbital and the others bond through the π-orbitals of the dmtu group. The Ni-S distances are 2.204 ± 0.002 Å and 2.230 ± 0.002 Å, and the Ni-S-C angles are 106.2 ± 0.2Å and 110.3 ± 0.3°. The dmtu groups are planar except for methyl hydrogens. The crystals are monoclinic, P21/a with a = 13.424 ± 0.002 Å, b = 12.321 ± 0.005 Å, c = 8.460 ± 0.008 Å β = 107.07 ± 0.05°, ρ0 = 1.67 g cm?3, ρc = 1.66 g cm?3 and Z = 2. The structure was refined by full-matrix least-squares to a conventional R of 0.0466. 相似文献
63.
《Journal of Coordination Chemistry》2012,65(3):483-490
Mononuclear NCS? containing complexes, [M(NCS)2L] (L?=?N,N-bis(3,5-dimethylpyrazol-1-ylmethyl)aminomethylpyridine), [Cu(NCS)2L′] (L′?=?N-(3,5-dimethylpyrazol-1-ylmethyl)aminomethylpyridine), and NCSe? containing complexes [ML(NCSe)(H2O)]ClO4 (M?=?Ni+2, Co+2) have been synthesized and characterized by elemental analysis, spectroscopic, and physico-chemical methods. Structural studies of [Cu(NCS)2L′] show copper is five coordinate with distorted trigonal bipyramidal geometry with two cis NCS?. [M(NCS)2L] and [ML(NCSe)(H2O)]ClO4 (M?=?Ni+2 and Co+2) are expected to be octahedral. 相似文献
64.
《Journal of Coordination Chemistry》2012,65(2):287-293
Using the flexible ligand 1,2-bis(1,2,4-triazole-1-yl)ethane (bte) and corresponding Ag(I) salts, a new two-dimensional (2-D) silver(I) complex {[Ag4(μ 4-bte)(μ 2-H2O)2](SiF6)2} n (1) has been isolated. 1 crystallizes in the orthorhombic Pcca space group. The bte adopts an unusual μ 4-tetradentate coordination mode to link neighboring AgI atoms forming infinite 1D Ag-bte tubular structures. Further neighboring Ag-bte tubes are inter-connected by relatively long Ag-(μ 2-H2O) bonds forming a 2-D layered structure. Solid-state fluorescence spectrum of 1 shows that the excitation peak is at 320 nm while the maximum emission peak is at 425 nm. 相似文献
65.
So Han Kim Junseong Lee Da Jung Kim Jung Hee Moon Sungwoo Yoon Hyung Jin Oh Youngkyu Do Young Soo Ko Jin-Heong Yim Youngjo Kim 《Journal of organometallic chemistry》2009,694(21):3409-3417
Several titanium isopropoxides 1–8 have been prepared by the reaction of Ti(O-i-Pr)4 with a series of corresponding tetradentate Salan-type [ONNO] ligands with benzyl or methyl substituents on bridging nitrogen atoms. They have been characterized by 1H NMR, 13C{1H} NMR, and elemental analysis. Solid state structures of compounds 2, 4, 6, and 7 have been determined by X-ray crystallography. X-ray diffraction analysis and 1H NMR confirmed that these titanium complexes were all monomeric species with a six-coordinated central titanium in their solid and solution structures. Complexes 2, 4, 6, and 8 with benzyl substituents on bridging nitrogens gave PLA with higher molecular weight than compounds 1, 3, 5, and 7 with methyl substituents did. 相似文献
66.
A new tetradentate imidazolate ligand 1,1′,1″,1′′′-(2,2′,4,4′,6,6′-hexamethylbiphenyl-3,3′,5,5′-tetrayl)tetrakis(methylene)(1H-imidazole) (L) and four Ag(I)/Cu(I) coordination polymers, namely [(MCN)3L]n (1: M=Ag; 2: M=Cu), and [(MSCN)2L]n (3: M=Ag; 4: M=Cu) are described. All four new coordination polymers were fully characterized by infrared spectroscopy, elemental analysis and single-crystal X-ray diffraction. Compound 1 features a 3D supramolecular framework constructed by 1D chains through inter-chain Ag-N(CN) and inter-layer Ag-N(L) weak interactions with an uninodal 66 topology. Complex 2 presents a 3D framework characterized by a tetranodal (3,4)-connected (3·4·5·102·11)(3·4·5·6·7·9)(3·6·7)(6·102) topology. Complexes 3 and 4 are isostructural, and both have a 3D network of trinodal 4-connected (4·85)2(42·82·102)(42·84)2 topology. The luminescent properties for these compounds in the solid state as well as the possible ferroelectric behavior of 1 are discussed. 相似文献
67.
68.
Isaac de los Rios Fabrizio Mani Piero Stoppioni 《Journal of organometallic chemistry》2004,689(1):164-169
The reaction of tetraphosphorus trichalcogenides P4X3 (X=S, Se) with the electronically and coordinatively unsaturated 16 electron systems [(EP3)Rh]+ [E=N, NP3=tris(2-diphenylphosphanylethyl)amine, (1); E=P, PP3=tris(2-diphenylphosphanylethyl)phosphane, (2)] in tetrahydrofuran affords new tetraphosphorus trichalcogenide derivatives of formula [(EP3)Rh(P4X3)]CF3 SO3 [E=N; X=Se (3), S (5). E=P; X=Se (4), S (6)]. In the P4Se3 derivatives 3 and 4 the heptatomic cage is bound to the metal through the apical phosphorus atom. The P4S3 derivatives 5 and 6 are obtained as pairs of coordination isomers, with the cage linked to the metal either through the apical or through one of the basal P atoms; the former isomer is predominant and its amount depends on the nature of the trans-disposed apical donor (N or P) of the tripodal ligand. The monometal species [(NP3)Rh(η1-P4S3)]CF3SO3 (5) reacts with 1 affording the dimetal compound [{(NP3)Rh}2(μ,η1:1-Papical,-Pbasal-P4S3)](CF3SO3)2, where the cage exhibits both modes of bonding. All of the compounds have been characterized by 31P NMR spectra and elemental analyses. 相似文献
69.
New macromolecular chelators have been synthesized, by loading 2,3-dihydroxypyridine (DHP) on cellulose via linkers -NH-CH2-CH2-NH-SO2-C6H4-N=N- and -SO2-C6H4-N=N-, and characterized by elemental analysis, TGA, IR, and CPMAS 13C NMR spectra. The cellulose with DHP anchored by the shorter linker had better sorption capacity (between 69.7 and 431.1 mol g–1) for Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Pb(II), and Fe(III)) than the other (51.9–378.1 mol g–1); the former was therefore studied in detail as a solid extractant for these metal ions. The optimum pH ranges for quantitative sorption (recovery 97.6–99.8%) on this matrix were: 7.0–9.0, 6.0–9.0, 3.0–8.0, 6.0–8.0, 6.0–9.0, 6.0–7.0, and 2.0–6.0 respectively. Desorption was quantitative with 0.5 mol L–1 HCl and 0.5 mol L–1 HNO3 (for Pb). Simultaneous sorption (at pH 7.0) of all metal ions other than Fe(III) was possible if their total concentration did not exceed the sorption capacity (lowest value). The recovery of seven metal ions from their mixture at pH 6.0 was nearly quantitative when the concentration level of each metal ion was 0.2 g mL–1. The optimum flow rate of metal ion solutions for quantitative sorption of metal onto a column packed with DHP-modified cellulose was 2–7 mL min–1, whereas for desorption the optimum flow rate for the acid solution was 2–4 mL min–1. The time needed to reach 50% of the total loading capacity (t1/2) was <5 min for all the metal ions except Ni and Pb. The limit of detection (blank+3s) was from 0.70 to 4.75 g L–1 and the limit of quantification (blank+10s) was between 0.79 and 4.86 g L–1. The tolerance limits for NaCl, NaBr, NaI, NaNO3, Na2SO4, Na3PO4, humic acid, EDTA, Ca(II), and Mg(II) for sorption of all metal ions are reported. The column packed with DHP-anchored cellulose can be reused at least 20 times for enrichment of metal ions in water sample. It has been used to enrich all the metal ions in pharmaceutical and water samples before their determination by flame AAS. RSD for these determinations was between 1.1 and 6.9%. 相似文献
70.
目前由人工合成的有机螯合微量元素肥料,因价格昂贵不能在农业生产中广泛应用。本研究采用丰富廉价的有机肥料,经转化提取的天然螯合剂与微量元素螯合研制的天然螯合微肥,在多种作物上施用,证明能促进作物对N、P、K和Fe、Mn、Zn、Cu等微量元素的吸收。明显提高作物的产量,改善品质,并不同程度地提高作物的抗病能力. 相似文献