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1.
G.J. Hager 《Applied Surface Science》2006,252(19):6558-6561
Utilizing Au4004+ primary ions produces large molecular ion yields, some in excess of unity, with minimal surface damage. A surprising observation is the occurrence of Au-analyte adducts as part of the ejecta desorbed by a single Au-cluster impact. We present data that demonstrate that Au and Au-adducts as secondary ions (e.g., AuCN−, AuGly− and AuCsI−) are the result of the interaction between a single primary ion, Au4004+ and the target atoms. 相似文献
2.
Dragan Mihailovic 《Monatshefte für Chemie / Chemical Monthly》2003,134(2):137-147
Ferromagnetism in fullerene-based systems doped with metallocenes is reviewed. These compounds form a ferromagnetic state
by spin-coupling between π electrons on fullerene units, while the metallocene molecules do not contribute to the spin ordering.
One of these compounds has the highest critical temperature (19 K) for this class of compound. The magnetic properties of
these materials are very strongly dependent on the crystallization conditions.
Corresponding author. E-mail: Dragan.Mihailovic@ijs.si
Received September 4, 2002; accepted September 6, 2002 相似文献
3.
Chloroacetaldehyde reacts with viral M13mp18 single and double stranded DNA to form the highly fluorescent adducts, etheno-AMP and etheno-CMP. Absorbance and fluorescence spectroscopy can be used to monitor and characterize these reactions. Both single and double stranded DNA showed increases in the absorbance following reaction with the aldehyde. The fluorescence also increased in these two groups and continued to rise with increasing time of incubation until a point of saturation was reached. The fluorescence of the double stranded moiety was considerably enhanced following reaction with the aldehyde while that of the single stranded population was not, making this method appropriate for the separation of small quantities of the two populations of DNA. 相似文献
4.
Gupta LK Bansal U Chandra S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,66(4-5):972-975
Nickel(II) complexes of isatin-3,2'-quinolyl-hydrazones of the type [Ni(L)X] (where X=Cl-, Br-, NO3-, CH3COO- and ClO4-] and their adducts Ni(L)X.2Y [where Y=pyridine or dioxane and X=Cl-, Br-, NO3- and ClO4-] have been synthesized under controlled experimental conditions and characterized by using the modern spectroscopic and physicochemical techniques viz. mass, 1H NMR, IR, electronic, elemental analysis, magnetic moment susceptibility measurements and molar conductance, etc. On the basis of spectral studies a four coordinated tetrahedral geometry is assigned for Ni(L)X type complexes whereas the adducts (Ni(L)X.2Y) were found to have a six coordinated distorted octahedral geometry. 相似文献
5.
6.
《Journal of Coordination Chemistry》2012,65(12):1003-1019
4,6-Diacetylresorcinol serves as a starting point for the generation of multidentate S/N/O or O/N/O symmetrical chelating agents by condensation with thiosemicarbazide or semicarbazide to yield the corresponding bis(thiosemicarbazone) H4L1 or bis(semicarbazone) H4L2, respectively. Reaction of H4L1 and H4L2 with M(NO3)2·6H2O (M?=?Co or Ni) afforded dimeric complexes for H4L1 and binuclear complexes for H4L2, revealing the tendency of S to form bridges. The dimeric cobalt complexes of H4L1 are very interesting in that they contain CoII/CoIII, side/side, low-spin octahedral coordinated CoIII-ions and high-spin square-planar coordinated CoII-ions. These complexes have the general formula [(H2L1)2Co2(H2O) (NO3)]·nEtOH. Arguments supporting these anomalous CoII/CoIII structures are based on a pronounced decrease in their magnetic moments, elemental and thermal analyses, visible and IR spectra, as well as their unreactivity towards organic bases such as 1,10-phenanthroline (phen), 2,2′-bipyridine (Bpy), N,N,N′,N′-tetramethylethylenediamine (Tmen) and 8-hydroxyquinoline (oxine, Ox). The dimeric octahedral NiII complex [(H2L1)2Ni2(H2O)4]·3H2O showed higher reactivity towards phen and Bpy and formed adducts; [(HL1)Ni2(B)(H2O)5] NO3 (B?=?phen or Bpy). In the presence of oxine, the dimeric brown paramagnetic octahedral complex [(H2L1)2Ni2(H2O)4]·3H2O was transformed to the dimeric brick-red diamagnetic square-planar complex [(H3L1)2Ni2](NO3)2. The latter showed dramatic behavior in its 1H NMR spectrum in DMSO-d 6, which was explained on the basis of H+-transfer. By contrast, the binuclear NiII–H4L2 complex (11) showed higher reactivity towards phen, Bpy and oxine. These reactions afforded mixed dimeric complexes having the molar ratio 2?:?2?:?1 (NiII?:?H4L2?:?base). The binuclear CoII–H4L2 complex afforded an adduct with phen and trinuclear complexes with Bpy and oxine. All complexes were found to be unreactive towards Tmen. Structural characterization was achieved by elemental and thermal analyses, spectral data (electronic, IR, mass and 1H NMR spectra) and conductivity and magnetic susceptibility measurements. 相似文献
7.
Anna-Francesca Lecoq Chiara Leuratti Erminio Marafante Sebastiano Di Biase 《Journal of separation science》1991,14(10):667-671
The use of micellar electrokinetic capillary chromatography (MECC) for the analysis of the major nucleobases, nucleosides, and nucleotides, and their chemically modified derivatives, has been developed and refined. The dimensions of the separating capillaries, the composition of the buffering systems, and the conditions used for electrophoresis were investigated in order to obtain the best performance. Particular emphasis was placed on the identification of the physiological constituents of nucleic acids and their chemically modified analogs: in vitro studies on calf thymus DNA exposed to genotoxic agents have demonstrated that adducted bases and nucleolides can be identified by MECC. 相似文献
8.
Tris(2,2,2-trichloroethoxy)chromium(III) tetrahydrofuran solvate, Cr(OCH2CCl3)3 ·THF; Chlorobis(2,2,2-trichloroethoxy)chromium(III)tetrahydrofuran solvate, CrCl(OCH2CCl3)2 ·THF and dichloro(2,2,2-trichloroethoxy) chromium(III) tetrahydrofuran solvate, CrCl2(OCH2CCl3) ·THF have been prepared. These compounds react with various oxygen and nitrogen donor ligands to form adducts of 1:2 composition. 2,2,2-trichloroethoxy bridged structures have been proposed on the basis of their infrared and1H nmr spectra. The diffuse reflectance spectral results are consistent with an octahedral geometry for chromium(III) whereas their low magnetic moment values suggest polymeric structures exhibiting antiferromagnetic coupling between chromium(III) atoms. The mass spectral data of Cr(OCH2CCl3)3 ·THF and CrCl(OCH2CCl3)2 ·THF support the dimeric structures for these complexes.
Synthese, Charakterisierung und Reaktionen von 2,2,2-Trichlorethoxyderivaten von Chrom(III)
Zusammenfassung Es wurde Tris(2,2,2-trichlorethoxy)chrom(III)-tetrahydrofuransolvat, Cr(OCH2CCl3)3 ·THF, Chlorbis(2,2,2-trichlorethoxy)chrom(III)tetrahydrofuransolvat, CrCl(OCH2CCl3)2 ·THF, und Dichlor(2,2,2-trichlorethoxy)chrom(III)tetrahydrofuransolvat, CrCl2(OCH2CCl3 ·THF, hergestellt. Diese Verbindungen reagieren mit verschiedenen Sauerstoff- und Stickstoffdonorliganden unter Bildung von Addukten mit der Zusammensetzung 1:2. Basierend auf IR- und1H-NMR-Daten wurden 2,2,2-trichlorethoxyüberbrückte Strukturen vorgeschlagen. Die Resultate aus Diffuse-Reflectance-Messungen sind mit einer oktaedrischen Geometrie um Cr(III) in Übereinstimmung, während die niedrigen Werte für die magnetischen Momente polymere Strukturen mit antiferromagnetischer Kopplung zwischen den Chrom(III)-Atomen nahelegen. Die massenspektroskopischen Daten für Cr(OCH2CCl3)3 ·THF und CrCl(OCH2CCl3)2 ·THF sprechen für eine dimere Struktur dieser Komplexe.相似文献
9.
In(C6F5)3 · CH3CN and In(C6F5)3 · glyme were synthesized from InCl3 and Cd(C6F5)2 in CH3CN or glyme in 43% and 35% yield, respectively. Replacement of CH3CN or (C2H5)2O by DMAP yielded the corresponding 1 : 1-adduct. [PNP][In(C6F5)4] was best prepared from the corresponding cesium salt which was best synthesized from the reaction of stoichiometric amounts of In(C6F5)3 · CH3CN, (CH3)3 SiC6F5 and CsF in good yield. [PNP][In(C6F5)4] crystallizes in the triclinic space group P 1, a = 1104.9(4) pm, b = 1442.4(6) pm, c = 1833.8(8) pm, α = 110.87(2)°, β = 92.04(3)°, γ = 96.55(3)°, Z = 2. 相似文献
10.
Subhradeep Dutta Dr. Jae Hyun Kim Kamal Bhatt Dillon R. L. Rickertsen Dr. Khalil A. Abboud Dr. Ion Ghiviriga Prof. Dr. Daniel Seidel 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(1):e202313247
A new strategy to access α-functionalized alicyclic amines via their corresponding imine-BF3 complexes is reported. Isolable imine-BF3 complexes, readily prepared via dehydrohalogenation of N-bromoamines in a base-promoted/18-crown-6 catalyzed process followed by addition of boron trifluoride etherate, undergo reactions with a wide range of organometallic nucleophiles to afford α-functionalized azacycles. Organozinc and organomagnesium nucleophiles add at ambient temperatures, obviating the need for cryogenic conditions. In situ preparation of imine-BF3 complexes provides access to α-functionalized morpholines and piperazines directly from their parent amines in a single operation. α-Functionalized morpholines can be elaborated further, for instance by installing a second substituent in the α′-position. 相似文献