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941.
Milan Melník Peter Mikuš 《Phosphorus, sulfur, and silicon and the related elements》2020,195(5):367-370
AbstractIn this review, the structural data of monomeric platinum(II) complexes with inner coordination spheres of Pt(η2-P2L)(SiL)2, Pt(η2-P2L)(η2-Si2L) and Pt(η2-P,SiL)2 are classified and analyzed. These complexes crystallize in three crystal systems: monoclinic (8 examples), triclinic (4 examples) and orthorhombic (4 examples). Distorted square-planar environments about the Pt(II) atoms are built up by combination of homobi-P,P with two monodentate Si donor ligands; homobi-PP with homo-Si,Si donor ligands, or heterobi-P,Si donor ligands. The chelating ligands create metallacycles with the following angles: 65.0° (SiOSi) < 83.1° (SiC2Si) < 85.2° (PC2P) < 88.8° (SiSi2Si)). The mean Pt-P and Pt-Si bond distances in Pt(η2-P2L)·(SiL)2 complexes are 2.319 and 2.365?Å; in Pt(η2-P2L)(η2-Si2L) the values are 2.316 and 2.360?Å. The complex [Pt{η2-Me2P(C2B10H10)SiMe2}2] exists in two isomeric forms, a monoclinic cis- and a triclinic trans-isomer. The structural data are compared and discussed with the complexes of inner coordination spheres: Pt(η2-P2L)(XL)2 (X?=?O, N, CN, BL, Cl, SL, SeL, Br, or I) and Pt(η2-P2L)(η2-X2L) (X?=?OL, NL, SL or SeL). 相似文献
942.
Continuous chemiluminescence determination of formaldehyde in air based on Trautz-Schorigin reaction 总被引:1,自引:0,他引:1
A new continuous method for the determination of formaldehyde in air is described. A cylindrical wet effluent diffusion denuder is used for the collection of formaldehyde from air into a thin film of absorption liquid (distilled-deionized water). Formaldehyde in the denuder concentrate is on-line detected employing a chemiluminescence flow method based on a reaction of formaldehyde and gallic acid with hydrogen peroxide in an alkaline solution. The collection efficiency of formaldehyde is quantitative at the air flow rate of 0.5 L min−1 (absorption liquid flow rate of 336 μL min−1). The limit of detection (S/N = 3) is 0.60 μg m−3 HCHO (0.49 ppb). The calibration graph is linear up to 300 μg m−3 HCHO (244 ppb). The relative standard deviations of chemiluminescence method for 1 × 10−6 and 5 × 10−6 M HCHO are 2.87% and 1.49%, respectively. Acetaldehyde interferes negligible, other compounds do not interfere. The method was employed for formaldehyde measurement in ambient air. The comparison measurement illustrates the good agreement of results obtained by proposed method with those obtained by reference fluorimetric method. 相似文献
943.
The UV. irradiation of 17β-acetoxy-4α, 5α-epoxy-2-oxaandrostan-3-one ( 7 ) yields 17β-acetoxy-2-oxa-10(5 → 4)abeo-4ζ (H)-androsta-3,5-dione ( 11 ). A non-photochemical synthesis of 11 , proceeding in lower yield, is also described. 相似文献
944.
Eduardo Corts C. Eduardo Corts R. María P. A. Fuentes B. 《Journal of mass spectrometry : JMS》1992,27(8):903-904
The mass spectra of twelve 2-methyl-3-(o- and p-R-phenyl)-3,3a,4,5,6,7-hexahydro-2H-indazoles which have potentially useful pharmacological properties are presented. 相似文献
945.
Analysis of endosulfan and its metabolites in human serum using gas chromatography-tandem mass spectrometry 总被引:5,自引:0,他引:5
Arrebola FJ Martínez Vidal JL Fernández-Gutiérrez A 《Journal of chromatographic science》2001,39(5):177-182
A new analytical method combining solid-phase extraction and gas chromatography-tandem mass spectrometry (GC-MS-MS) is proposed to determine the insecticide endosulfan as well as its metabolites endosulfan-ether, -lactone, and -sulfate in human serum. Most matrix interferences are avoided using a cleanup step included in the sample treatment and an instrumental technique such as GC-MS-MS, which presents a high sensitivity and selectivity. Recoveries of spiked compounds range between 94.8 and 100.4% and 93.4 and 99.7% at fortification levels of 10 and 30 ng/mL, respectively. The relative standard deviation is lower than 17.6% in all cases, and the limits of detection calculated range from 6 to 19 pg/mL. Serum samples of nine agricultural workers that spray endosulfan into greenhouses in Almería (Spain) and two nonoccupationally exposed people are analyzed, and endosulfan is found in all the samples studied. 相似文献
946.
Mounir Maafi Belkacem Laassis Jean-Jacques Aaron M. Carmen Mahedero Arsenio Muñoz De La Peña Francisco Salinas 《Journal of inclusion phenomena and macrocyclic chemistry》1995,22(3):235-247
The photooxidation of Azure A and fluorescence properties of Azure A and its photoproduct have been investigated in aqueous media and in the presence of-cyclodextrin (-CD). The fluorescence intensity of the complex formed between the photoproduct and -CD was found to be three times higher than that of the uncomplexed Azure A photoproduct. A complex formation constant of 110±40 M–1 was calculated using the Benesi-Hildebrand treatment of the fluorescence emission data. Although the stoichiometry of the Azure A photoproduct: -CD complex was found to be 1: 1, it seems that the Azure A structure is only partially included. Calibration graphs were plotted for the free Azure A photoproduct and the photogenerated product included in -CD. The analytical parameters and quantification limits were determined. 相似文献
947.
Román-Bravo P López-Cardoso M y García PG Höpfl H Cea-Olivares R 《Chemical communications (Cambridge, England)》2004,(17):1940-1941
The molecular structures of two lipophilic polyion aggregates derived from tetraphenyl imidodiphosphinate are described: [Na(crown ether)][MNa(2)[Ph(2)P(O)NP(O)Ph(2)](4)] with crown ether = 15-crown-5 for 1and benzo-15-crown-5 for (M = Na(+) for 1 and Na(H(2)O)(+) for 2). 相似文献
948.
Imre T Schlosser G Pocsfalvi G Siciliano R Molnár-Szöllosi E Kremmer T Malorni A Vékey K 《Journal of mass spectrometry : JMS》2005,40(11):1472-1483
A new anionic surfactant (RapiGest SF) was successfully used for site-specific analysis of glycosylation in human alpha-1-acid glycoprotein (AGP). By means of this analytical approach combined with capillary HPLC-mass spectrometry (and tandem mass spectrometry), the N-linked glycosylation pattern of AGP was explored. On the basis of mass matching and MS/MS experiments ca 80 different AGP-derived glycopeptides were identified. Glycosylation shows a markedly different pattern for the various glycosylation sites. At sites I and II, triantennary complex-type oligosaccharides predominate and at sites III, IV and V, tetra-antennary complex-type oligosaccharides predominate. Sites IV and V show the presence of additional N-acetyl lactosamine (Gal-GlcNAc) units (even higher degree of branching and/or longer antennae are also present). 相似文献
949.
Gregorio López María D. Santana Gabriel García Gregorio Sánchez Joaquín García 《Transition Metal Chemistry》1987,12(2):130-133
Summary The organopalladium(II) complexes: Pd(2,4,6-C6F3H2)2L2 [L=triphenylphosphine(PPh3), methyldiphenylphosphine(PPh2Me), dimethylphenylphosphine-(PPhMe2) or pyridine(py); L2=1,2-bis(diphenylphosphino)ethane(dpe), 2,2-bipyridine(bipy), 1, 10-phenanthroline(phen) or ethylenediamine(en)] have been prepared by addition of the appropriate compound to the THF-dioxane solution resulting from the arylation of potassium tetrachloropalladate(II) with (2,4,6-C6F3H2)MgBr. The i.r. data suggest that the py and PPhMe2 compounds are thecis-isomers, whereas the PPh3 and PPh2Me compounds have thetrans configuration.1H- and19F-n.m.r. data for the compounds are reported. 相似文献
950.