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51.
Vidyakina A. A. Zheglov D. A. Oleinik A. V. Freinkman O. V. Kolesnikov I. E. Bogachev N. A. Skripkin M. Yu. Mereshchenko A. S. 《Russian Journal of General Chemistry》2021,91(5):844-849
Russian Journal of General Chemistry - Microcrystalline anti-Stokes luminophores NaY1–x–y–zYbxEryLuzF4 were obtained for the first time by hydrothermal synthesis. These compounds... 相似文献
52.
Anatoly V Skalny Margarita G Skalnaya Andrei R Grabeklis Elena S Berezkina Eugeny P Serebryansky Vasily A Demidov 《International journal of environmental analytical chemistry》2017,97(6):520-533
The existing data provide information on hair essential and toxic trace element content, whereas data on ultra-trace and rare elements are scarce. Therefore, the primary aim of the current study was to estimate hair levels and reference values of hair rare metal content using IUPAC recommendations in 2593 occupationally non-exposed adults living in Moscow and Novosibirsk (1900 women and 693 men). Hair Ag, Au, Ga, Ge, La, Rb, Tl, W and Zr content was assessed by inductively coupled plasma mass spectrometry with NexION 300D. Women were characterised by significantly higher hair Ag and Au levels than men, whereas men had increased La, Rb, Tl, W and Zr content as compared to women. Moscow inhabitants were characterised by significantly higher hair Au and Ge, and lower hair Ga, La, Rb, Tl, W and Zr content as compared to the ones from Novosibirsk. The coverage intervals of Ag, Au, Ga, Ge, La, Rb, Tl, W and Zr content in hair of the general sample of examinees calculated in accordance with IUPAC recommendations were 0.0278–0.2994, 0.0159–0.1812, 0.0062–0.0348, 0.0022–0.0066, 0.0023–0.0205, 0.0226–0.2083, 0.0002–0.0008, 0.0022–0.0120 and 0.0389–0.3521 μg/g, respectively. The obtained data indicate that both gender and geographical location affect hair rare metal content in adults. 相似文献
53.
G. L. Starova K. K. Spektor Yu. M. Skripkin 《Russian Journal of General Chemistry》2011,81(9):1768-1771
Structures of three mixed solvates of copper halides: CuBr2·DX·2H2O, CuBr2·2DX·2H2O, and CuCl2·2DX·2H2O (DX is 1,4-dioxane) has been determined by the method of XRD on single crystals. The entry of both solvents into the first
coordination sphere of the copper ion was proved. In spite of analogous composition, CuHlg2·2DX·2H2O solvates have different structures: the chain (Hlg = Br) and the island (Hlg = Cl) structures. The difference is caused
by weakening donor power of acido ligands on passing from Br to Cl. 相似文献
54.
Ermilov EA Menting R Lau JT Leng X Röder B Ng DK 《Physical chemistry chemical physics : PCCP》2011,13(39):17633-17641
Porphyrins and phthalocyanines are two attractive classes of functional dyes for the construction of artificial light harvesting and charge separation molecular systems. The assembly of these components by supramolecular approach is of particular interest as this provides a facile route to build multi-chromophoric arrays with various architectures and tuneable photophysical properties. We report herein a series of host-guest complexes formed between a tetrasulfonated porphyrin and several silicon(IV) phthalocyanines substituted axially with two permethylated β-cyclodextrin units via different spacers. As shown by electronic absorption and fluorescence spectroscopic methods, the two components bind spontaneously in a 1:1 manner in water with large binding constants in the range of 1.1 × 10(7) to 3.5 × 10(8) M(-1). The photophysical properties of the resulting supramolecular complexes have also been studied in detail using steady-state and time-resolved optical spectroscopic methods. It has been found that two major photoinduced processes, namely fluorescence resonance energy transfer and charge transfer are involved which are controlled by the spacer between the β-cyclodextrin units and the silicon centre of phthalocyanine. Despite the fact that charge transfer is a thermodynamically favourable process for all the complexes, only the ones with a tetraethylene glycol or oxo linker exhibit an efficient charge transfer from the excited phthalocyanine to the porphyrin entity. The lifetimes of the corresponding charge-separated states have been determined to be 200 and 70 ps by picosecond pump-probe experiments. 相似文献
55.
Rusakova N Smola S Martsinko E Seifullina I Ermilov E Korovin Y 《Journal of fluorescence》2008,18(2):247-251
New lanthanide–germanium complexes with diethylenetriaminepentaacetic acid (DTPA) have been synthesized and were characterized
by means of elemental analysis, IR-, UV-absorption and luminescent spectroscopy. The 4f-luminescence of heteronuclear Ln(Ge-DTPA)2
(Ln=Sm, Eu, Tb, Dy) complexes in aqueous solutions was investigated for the first time. 相似文献
56.
57.
Yu.V. Skripkin O.G. Volkov A.A. Pasynskii A.S. Antsyshkina L.M. Dikareva V.N. Ostrikova M.A. Porai-Koshits S.L. Davydova S.G. Sakharov 《Journal of organometallic chemistry》1984,263(3):345-357
Treatment of niobocene carbonylhydride, Cp2Nb(CO)H (I), with PhnSnCl4?n and Et2SnCl2 in THF in the presence of Et3N leads to the respective heteronuclear complexes Cp2Nb(CO)SnRnCl3?n (R = Ph, n = 3 ÷ 1 (II–IV), R = Et, n = 2 (V)). Treatment of II with HCl in ether gives Cp2Nb(CO)SnCl3 (VI). Complex VI and its analog (MeC5H4)2Nb(CO)SnCl3 (VIII) were prepared by an alternative synthesis using direct reaction of I or (MeC5H4)2Nb(CO)H with an equimolar quantity of SnCl4 in THF in the presence of Et3N. Complex VI is also generated by insertion of SnCl2 into the NbCl bond in Cp2Nb(CO)Cl (VII). X-Ray analysis of complexes II and VIII was performed: for II, space group P21/n, a = 10.1021(21), b = 17.4633(32), c= 14.2473(29) Å, β = 95.578(16)°, Z = 4; for VIII, space group. P21/n, a= 8.9369(15), b = 13.3589(12), c = 13.9292(20) Å, β = 99.490(14)°, Z = 4. The NbSn bond in VIII (2.764(9) Å) is shorter than that in II (2.825(2) Å). In both cases the NbSn bond is significantly shorter than the sum of Nb and Sn covalent radii (1.66 + 1.40 = 3.06 Å). It is probably partly multiple in character owing to an additional interaction of the lone electron pair of the NbIII ion (d2 configuration) with the antibonding Sn orbitals. The PMR spectra of II–VI exhibit two satellites of the singlet of C5H5 protons because of HSn117 and HSn119 spin-spin coupling (SSC). The SSC constant correlates with the number of electronegative chlorine atoms on the Sn atom. 相似文献
58.
A.A. Pasynskii Yu.V. Skripkin V.T. Kalinnikov M.A. Porai-Koshits A.S. Antsyshkina G.G. Sadikov V.N. Ostrikova 《Journal of organometallic chemistry》1980,201(1):269-281
CpFe(CO)2CH3 reacts with Cp2NbH made from Cp2NbBH4 and Et3N to give Cp2e (III). As shown by X-ray diffraction, III contains the Cp2NbH sandwich fragment with a 46.8° angle between the rings linked with the dicarbonyliron moiety by the NbFe bond (2.968 Å), observed for the first time, and a cyclopentadienyl bridge C5H4, involving the NbC. σ-bond (2.189 Å) and C5H4Fe π-bond (2.085 Å). A probable reaction scheme leading to III and general patterns of formation of other heterobinuclear derivatives of sandwich complexes Cp2MLM′(L′)n are discussed. The importance of steric effects due to nonbonded interligand interactions between the M′(L′)n fragment and the sandwich system is emphasized. Increase of steric strain in the binuclear system facilitates its unusual transformations. 相似文献
59.
Kachalova A Zubin E Stetsenko D Gait M Oretskaya T 《Organic & biomolecular chemistry》2004,2(19):2793-2797
An efficient method for synthesis of oligonucleotide 2'-conjugates via amide bond formation on solid phase is described. Protected oligonucleotides containing a 2'-O-carboxymethyl group were obtained by use of a novel uridine 3'phosphoramidite, where the carboxylic acid moiety was introduced as its allyl ester. This protecting group is stable to the conditions used in solid-phase oligonucleotide assembly, but easily removed by Pd(0) and morpholine treatment. 2'-O-Carboxymethylated oligonucleotides were then efficiently conjugated on a solid support under normal peptide coupling conditions to various amines or to the N-termini of small peptides to give products of high purity in good yield. The method is well suited in principle for the preparation of peptide-oligonucleotide conjugates containing an amide linkage between the 2'-position of an oligonucleotide and the N-terminus of a peptide. 相似文献
60.