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991.
A new combination bismuth bulk electrode allowing potentiostatic control to be maintained in a suspended sample drop is described. The electrode was tested by adsorptive constant‐current stripping chronopotentiometry for iron(III) using Solochrome Violet RS. Optimum conditions were similar to those established with mercury‐based electrodes. With an electropolishing scheme, a reproducibility better than 2 % (n=54) was attainable. The limit of detection was 0.6 µg L?1 in deoxygenated samples. A partial least squares calibration gave a result of 972±78 µg L?1 (95 %, n=5) for a 1000±5 µg L?1 iron reference solution. 相似文献
992.
Lorena M. CallejoNoelia De la Pinta Gotzon MadariagaLuis Lezama M. Luz FidalgoRoberto Cortés 《Polyhedron》2011,30(6):923-928
Here we report the synthesis and characterization by X-ray diffraction, FTIR, UV-Vis and EPR spectroscopies, and the magnetic measurements of two new compounds: [Mn(NCS)2(bpe)2(H2O)2] (1) and [Fe(NCS)2(bpe)2(H2O)2] (2) (bpe = 1,2-bis(4-pyridyl)ethylene). Single-crystal structure analyses reveals discrete octahedral metal units that are assembled into 2D sheets through O-Hw?N(bpe) and O-Hw?S(thiocyanate) hydrogen bonds. The intermetallic M?M distances are 6.90 and 6.87 Å for 1 and 2, respectively. Supramolecular architectures are obtained by connections through H-bonds. Slight interactions are observed for compound 2. 相似文献
993.
Shengju Song Carl Redshaw Xiang Hao Wen-Hua Sun 《Journal of organometallic chemistry》2011,696(13):2594-137
The series of bidentate N^N iron(II) and cobalt(II) complexes containing 8-(1-aryliminoethylidene) quinaldine derived ligands, 8-[2,6-(R1)2-4-R2-C6H2NC (Me)]-2-Me-C10H5N, were synthesized and characterized by elemental and spectroscopic techniques. The molecular structures of Co1 (R1 = Me, R2 = H), Co3 (R1 = iPr, R2 = H) and Co4 (R1 = R2 = Me) were confirmed as the distorted tetrahedral by single crystal X-ray diffraction. On treatment with modified methylaluminoxane (MMAO), these complexes exhibited good catalytic activities of up to 5.71 × 105 g mol−1(Fe) h−1 for the ethylene dimerization at 30 °C under 10 atm of ethylene, in which iron pre-catalysts produced butenes with a high selectivity for α-butene. The correlation between metal complexes, catalytic activities and the product formed were investigated under various reaction parameters. 相似文献
994.
Nazhen Liu 《Journal of organometallic chemistry》2011,696(13):2537-370
Dibenzylphenylphosphine in the reaction with CoMe(PMe3)4 afforded complex [(Me3P)3Co((ortho-C6H4)∩P(C6H5)(CH2C6H5))] (1) by Csp2-H activation via ortho-metalation with P atom as anchoring group. An unexpected dinitrogen iron(II) complex [(Me3P)2(N2)Fe((ortho-C6H4)2∩P(C6H5))] (2) stabilized by two five-membered chelate rings as [CPC]-pincer ligand was formed through the reaction of dibenzylphenylphosphine with FeMe2(PMe3)4 via double Csp2-H activation. The reactions of complexes 1 and 2 with carbon monoxide delivered carbonyl complexes [(Me3P)(CO)2Co((ortho-C6H4)∩P(C6H5)(CH2C6H5))] (3) and [(Me3P)2(CO)Fe((ortho-C6H4)2∩P(C6H5))] (4). An iodo methyl cobalt(III) complex [(Me3P)2(Me)(I)Co((ortho-C6H4)∩P(C6H5)(CH2C6H5))] (5) was isolated through the reaction of 1 with iodomethane. The structures of 1, 2, 3, 4 and 5 were determined by X-ray diffraction. 相似文献
995.
Shishir Ghosh Kaniz Fatema Md. Rafique Al-Mamun Graeme Hogarth 《Journal of organometallic chemistry》2011,696(18):2935-2942
Reaction of [Mn2(CO)9(NCMe)] with tetrahydropyrimidine-2-thione (thpymSH) at 25 °C furnishes the mono- and dinuclear complexes [Mn(CO)4(κ1:η1-SCNHC3H6NCO)] (2) and [Mn2(CO)6(μ-thpymS)2] (1), respectively. Carbon-nitrogen coupling is observed in compound 2 resulting in the formation of κ1:η1-SCNHC3H6NCO ligand while compound 1 adopts a centrosymmetric structure. Reaction of 1 with [Os3(CO)10(NCMe)2] at 80 °C affords the mixed Mn-Os cluster [MnOs3(CO)13(μ3-thpymS)] (3) which possesses a butterfly skeleton of four metal atoms whereas with Ru3(CO)12 at 110 °C gives the mixed Mn-Ru complex [MnRu3(CO)14(μ4-S)(κ1:η1-thpym)] (4). In contrast, treatment of 1 with Fe3(CO)12 at 80 °C furnishes two triiron complexes [Fe3(CO)9(μ3-S)(μ3-κ1:η1-C4H6N2)] (5) and [Fe3(CO)8(μ3-S)2(η1-C4H8N2)] (6). The former also results from the direct reaction of thpymSH with Fe3(CO)12 and reacts with H2S to afford 6. The molecular structures of all these new complexes have been determined by X-ray diffraction studies. 相似文献
996.
Santino Orecchio 《Microchemical Journal》2011,99(1):132-137
Manufacture technology involves several aspects of pottery making, such as the type and the atmosphere of firing to obtain the finished item. During the firing of clay, at different environment of the oven, different compounds of iron (Fe(II) and Fe(III)) are formed and this is the reason for a different color of the ceramic body. Despite the great interest in this field, no works are devoted to the study the speciation of iron in ancient ceramics.The proposed method, even if considered destructive by archaeologists, allows the speciation of iron, using quantity of sample in the order of milligram. In order to achieve information about their firing conditions, thirty-nine pottery samples belonging to the archaeological Sicilian site of Himera (Sicily, Italy) were characterized for Fe(II) and Fe(III) by means of a UV-Vis spectrophotometric method proposed by us, while total iron was checked by ICP-OES. Were identified two groups of samples, the first (A), which is particularly rich in Fe(II) (the archaeologists have not identified the stylistic characteristics of most of this samples) the last group is instead rich Fe(III). 相似文献
997.
Figueroa-Cisterna J Bagur-González MG Morales-Ruano S Carrillo-Rosúa J Martín-Peinado F 《Talanta》2011,85(5):2307-2315
The combination of “ex situ” portable X ray fluorescence with unsupervised and supervised pattern recognition techniques such as hierarchical cluster analysis, principal components analysis, factor analysis and linear discriminant analysis have been applied to rock samples, in order to validate a “in situ” macroscopic rock samples classification of samples collected in the Boris Angelo mining area (Central Chile), during a drill-hole survey carried out to evaluate the economic potential of this Cu deposit. The analysed elements were Ca, Cu, Fe, K, Mn, Pb, Rb, Sr, Ti and Zn. The statistical treatment of the geological data has been arisen from the application of the Box-Cox transformation used to transform the data set in normal form to minimize the non-normal distribution of the data. From the statistical results obtained it can be concluded that the macroscopic classification applied to the transformed data permits at least, to distinguish quite well in relation to two of the rock classes defined (70.5% correctly classified (p < 0.05)) as well as for four of the five alteration types defined “in situ” (75% of the total samples). 相似文献
998.
FeCl3·6H2O-promoted skeleton-rearrangement of 1-substituted-3-benzazepines was further exploited. Both 1-aryl- and 1-alkyl- or 1-alkenyl-benzazepines underwent this reaction smoothly. The rearrangement products were used to prepare a series of novel derivatives containing both tetrahydroisoquinoline (THIQ) and tetrahydropyrimidin-4(1H)-one scaffolds through a Mannich-type process. 相似文献
999.
Eight gemini bis-2-(2-hydroxyphenyl)-thiazole-4-carboxamide and -thiocarboxamide (BHPTC) chelators were efficiently synthesized. Mass spectrometry showed these compounds all form 1:1 complexes with iron(III). Three of these chelators exhibit promising antiproliferative activities when tested on human cancerous cell lines. 相似文献
1000.
A method for the facile synthesis of tetraaryl-trimethylsilylmethyl-hydro[60]fullerenes, C60Ar4(CH2SiMeR)H, has been developed in which readily prepared anionic mono(silylmethyl) fullerene is subjected to reaction conditions for organocopper-mediated multiple addition. Penta(organo)fullerene derivatives bearing different substituents and diverse functionality were synthesized in moderate to good yield under simple and mild reaction conditions. Further organic and organometallic transformations of these fullerenes allowed us to synthesize transition-metal complexes and a new methanofullerene derivative, 1,9-methano-6,12,15,18-tetraphenyl[60]fullerene, C60Ph4(CH2). 相似文献