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1.
Ivanov A. V. Antzutkin O. N. Forsling W. Rodionova N. A. 《Russian Journal of Coordination Chemistry》2003,29(5):301-306
Binuclear diisopropyl and dicyclohexyl dithiophosphate cadmium complexes, namely, [Cd2{S2P(OR)2}4], were studied by high-resolution heteronuclear (13C, 31P, and 113Cd) NMR spectroscopy in the solid state in a temperature range from 295 to 378 K. 31P NMR signals for the terminal and bridging ligands of the complexes were differentiated. The experimental NMR spectra show 31–111,113Cd and 113Cd–31 spin–spin couplings only for the terminal ligands. The chemical shift anisotropy aniso and the asymmetry parameter were calculated for 31P and 113Cd NMR signals. It was found that the 31P chemical shifts for the terminal and bridging dithiophosphato groups differ in anisotropy character. 相似文献
2.
A. V. Ivanov E. V. Korneeva B. V. Bukvetskii A. S. Goryan O. N. Antzutkin W. Forsling 《Russian Journal of Coordination Chemistry》2008,34(1):59-69
The structures and spectroscopic properties of mononuclear and binuclear mercury(II) and copper(II) complexes with four dithiocarbamate ligands R2NC(S)S? (R = CH3, C2H5, or iso-C3H7; R2 = (CH2)6) were studied by solid-state 13C and 15N CP/MAS NMR and EPR spectroscopy. Mercury(II) N,N-cyclohexamethylenedithiocarbamate [Hg2{S2CN(CH2)6}4] was obtained and characterized in detail by X-ray diffraction analysis at 299 K. The binuclear molecule of the complex is centrosymmetric; the central tricyclic fragment [Hg2S4C2] is in the chair conformation. In the 13C and 15N NMR spectra, the signals were assigned to the dithiocarbamate ligands with different structural functions: bidentate chelating and combined (both chelating and bridging) ones. The differences between the isotropic 15N chemical shifts for the dialkyldithiocarbamate ligands were interpreted in terms of combination of the mesomeric effect of the =NC(S)S-groups and the inductive effect of the alkyl substituents. According to the EPR data, copper(II) in magnetically diluted systems is mainly found in heterobinuclear molecules [CuHg(S2CNR2)4] and the geometry of the chromophores [CuS5] approximates to a tetragonal pyramid. 相似文献
3.
A. V. Ivanov A. S. Zaeva E. V. Novikova T. A. Rodina W. Forsling 《Russian Journal of Inorganic Chemistry》2007,52(5):691-697
Crystalline adducts of zinc and copper(II) dithiocarbamate (Dtc) complexes with dialkylamines [M(NHR′2)(S2CNR2)2] (M = Zn, 63Cu, 65Cu; R = CH3, C2H5, or R2 = (CH2)4O; R′ = C2H5, C3H7) have been preparatively isolated. The structures and spectral properties of the adducts have been studied by EPR and 13C and 15N MAS NMR. Chemisorption of bases on powders of dinuclear dithiocarbamates leads to their dissociation into monomeric adducts. Computer simulation demonstrates that the experimental EPR spectra of isotope-substituted copper(II) adducts have an individual character. The geometry of the copper polyhedra is intermediate between a trigonal bipyramid (TBP) and a tetragonal pyramid (TP). The TBP and TP contributions have been quantified based on EPR data. 13C and 15N MAS NMR data show that the Dtc ligands incorporated into the zinc adduct molecule are structurally nonequivalent. The dependence of the isotropic 15N chemical shifts of the Dtc groups on the alkyl substituents at the nitrogen atom is interpreted based on the concept of joint manifestation of the (+)inductive effect of the alkyl substituents and the mesomeric effect of the Dtc groups. 相似文献
4.
T. A. Rodina A. V. Ivanov S. I. Lavrent’eva A. V. Gerasimenko O. N. Antzutkin 《Russian Journal of Inorganic Chemistry》2008,53(7):1098-1109
The zinc O,O’-di-iso-propyl phosphorodithioate complex [Zn4O?ub;S2P(O-iso-C3H7)2?ub;6] (I) has been synthesized and characterized by multinuclear MAS NMR (13C, 31P). The metal core of the tetranuclear structure of I, determined by single-crystal X-ray diffraction, is a tetrahedron centered by an oxygen atom. All Dtph ligands are structurally nonequivalent and act as μ2 bridges combining pairs of zinc atoms. Bonding of all metal atoms to the μ4 oxygen atom provides additional stabilization of the structure. For 31P NMR signals, the chemical shift anisotropy δaniso and the asymmetry parameter η were calculated, which allowed to assign them to the phosphorus positions in the structure of I. 相似文献
5.
195Pt, 1H, and 13C NMR spectroscopy was used to study the structure of binuclear platinum(III) acetamidate complexes with 1,10-phenanthroline and 2,2′-bipyridine ligands [Pt2(phen)2(acam)4](NO3)2 (1) and [Pt2(bipy)2(acam)4](NO3)2 (2) in aqueous solutions. The 195Pt NMR spectra of solutions of complexes 1 and 2 in D2O exhibit two signals with satellites due to the 195Pt–195Pt spin-spin coupling (1 J(Pt–Pt) ≈ 6345 Hz), whereas their 1H and 13C NMR spectra contain four sets of signals for the protons and the carbon atoms of the heterocyclic and acetamidate ligands. The signals were assigned using the COSY, NOESY, and HSQC/ HMBC experiments and comparing the coordination shifts of the signals for the protons of heterocycles. These data allowed us to draw a conclusion that binuclear complexes 1 and 2 in solution have a head-to-head structure with nonequivalent platinum(III) atoms (coordination cores PtN5 and PtN3O2), the axial-equatorial coordination of the bidentate heterocyclic molecules, and two bridging and two terminal acetamidate ligands. 相似文献
6.
A. V. Ivanov A. S. Zaeva E. V. Novikova A. V. Gerasimenko W. Forsling 《Russian Journal of Coordination Chemistry》2007,33(4):233-243
Crystalline adducts of zinc and copper(II) dithiocarbamate complexes with dibutyl-and diisobutylamines of the general formula [M(NHR′2)(S2CNR2)2] (M = Zn, 63Cu, and 65Cu; R = CH3 and C2H5; R2 = (CH2)4O; R′ = C4H9 and i-C4H9) were synthesized. Their structures and spectroscopic properties were studied by EPR and solid-state natural abundance 13C and 15N CP/MAS NMR spectroscopy. Experimental EPR data and computer-assisted modeling confirmed the individual character of copper(II) adducts. The geometries of the copper coordination polyhedra were found to be intermediate between a tetragonal pyramid and a trigonal bipyramid (TBP). The contributions from TBP to the geometries of the adducts obtained were calculated from the EPR data. According to the X-ray diffraction data, the adduct of zinc diethyldithiocarbamate with diisobutylamine exists in two isomeric forms. The 13C and 15N CP/MAS NMR signals were assigned to the atomic positions in two crystallographically independent conformer molecules. 相似文献
7.
The solid-phase nitration and acetylation processes of bacterial cellulose have been investigated mainly by CP/MAS 13C NMR spectroscopy to clarify the features of these reactions in relation to the characterization of the disordered component included in the microfibrils. CP/MAS 13C NMR spectra of bacterial and Valonia cellulose samples are markedly changed as the nitration progresses, in a similar way to the case of cotton linters previously reported; and the relative reactivity of the OH groups in the glucose residues is found to decrease in the order of O(6)H>O(2)H>O(3)H. Moreover, the nitration rate and mode greatly depend on the concentration of nitric acid in the reaction media. At dilute and medium concentrations, the O(6)H groups in the crystalline and disordered components are subjected to nitration at nearly the same rate, indicating that these two components are distributed almost at random in the entire region of each microfibril. The preferential penetration of nitric acid into each microfibril also occurs prior to nitration at the medium concentration, resulting in an increase in the mole fraction of the disordered component. In contrast, all OH groups undergo nitration very rapidly at the higher concentration, although nitration levels off to a certain extent for O(3)H groups. In solid-phase acetylation, no regio-selective reactivity is observed among the three kinds of OH groups, which may be due to the characteristic reaction that proceeds in a very thin layer between the acetylated and nonacetylated regions in each microfibril. The almost random distribution of the disordered component in the entire region of the microfibrils is also confirmed in this solid-phase acetylation. On the basis of these results, the mechanism of the solid-phase reactions and the microfibril structure are discussed. 相似文献
8.
Lenoble V Garnier C Masion A Ziarelli F Garnier JM 《Analytical and bioanalytical chemistry》2008,390(2):749-757
This work allowed the characterization of the Cd-binding sites of two compounds taken as models for exudates, the main components
of soil organic matter (SOM). The studied compounds were exopolysaccharides (EPS), specifically exudates of roots (polygalacturonic
acid) and of soil bacteria (Phytagel). Potentiometric acid–base titrations were performed and fitting of the obtained results
indicated the presence of two main classes of acidic sites, defined by their pK
a values, for both EPS but of a different nature when comparing the two compounds. The two studied exopolysaccharides presented
different acidic/basic site ratios: 0.15 for Phytagel and 0.76 for polygalacturonic acid. Spectroscopic techniques (13C/113Cd NMR, FTIR) distinguished different Cd surroundings for each of the studied EPS, which is in agreement with the titration
results. Furthermore, these analyses indicated the presence of –COOH and –OH groups in various proportions for each exopolysaccharide,
which should be linked to their reactivity towards cadmium. Cadmium titrations (voltammetric measurements) also differentiated
different binding sites for each compound and allowed the determination of the strength of the Cd-binding site of the EPS.
Fitting of the results of such voltammetric measurements was performed using PROSECE (Programme d’Optimisation et de Speciation Chimique dans l’Environnement), a software coupling chemical speciation calculation and binding parameter optimization. The fitting, taking into account
the Cd2+/H+ competition towards exopolysaccharides, confirmed the acid-base titrations and spectroscopic analyses by revealing two classes
of binding sites: (i) one defined as a strong complexant regarding its Cd2+–EPS association (logK = 9–10.4) and with basic functionality regarding H+–EPS association (pK
a = 11.3–11.7), and (ii) one defined as a weak complexant (logK = 7.1–8.2) and with acidic functionality (pK
a = 3.7–4.0). Therefore the combination of spectroscopic analyses, voltammetry, and fitting allowed the precise characterization
of the binding sites of the studied exopolysaccharides, mimicking the main SOM components. Furthermore, the binding parameters
obtained by fitting can be used in biogeochemical models to better define the role of key SOM compounds like exudates of roots
and of soil bacteria on trace metal transport or assimilation. 相似文献
9.
10.
O. V. Loseva T. A. Rodina A. V. Ivanov A. V. Gerasimenko O. N. Antsutkin 《Journal of Structural Chemistry》2013,54(3):598-606
We study the interaction of dialkyl substituted and cyclic cadmium dithiocarbamates with [AuCl4]? anions in 2M HCl medium. The state of the chemisorbents upon contact with AuCl3 solutions is controlled by 113Cd MAS NMR spectroscopy. The result of the heterogeneous reactions involving chemisorption binding of gold(III) from the solutions and partial ion exchange is the formation of heteropolynuclear gold(III)-cadmium complexes. The crystal and molecular structure of the acetone-solvated form of polymeric bis-(N,N-diethyldithiocarbamato-S,S′) gold(III) hexachlorodicadmate is identified by single-crystal XRD. The main structural moieties of the compound are complex [Au{S2CN(C2H5)2}2]+ cations and [Cd2Cl6]2? anions. The structural self-organization of the complex at the supramolecular level is attributed to the secondary Au…S bonds between neighboring isomeric complex gold(III) cations; the bonding results in the formation of linear polymer ([Au{S2CN(C2H5)2}2]+) n chains, with [Cd2Cl6]2? anions alternating to the right and left of the chains. 相似文献
11.
M. A. Fedotov V. V. Molchanov R. N. Zotov F. V. Tuzikov 《Russian Journal of Inorganic Chemistry》2008,53(10):1621-1627
Solutions of aluminum alkoxides obtained by interaction of aluminum metal with methyl, ethyl, and isopropyl alcohols were studied by 27Al and 13C NMR and small-angle X-ray scattering. Alkoxides with a tetrahedral environment of aluminum prevail in methanol solutions, and those with an octahedral environment of aluminum predominate in ethanol solutions. In isopropyl alcohol at 293 K, polynuclear alkoxides with tetrahedral, octahedral, and pentacoordinated aluminum environments coexist. The structure of polynuclear complexes was refined by comparison of their calculated dimensions with small-angle X-ray scattering data. 相似文献
12.
Four different diatom species (Chaetoceros debilis, Chaetoceros didymum, Cylindrotheca fusiformis, Nitzschia angularis) were studied by solid-state (29)Si MAS NMR spectroscopy. To determine the Q(2):Q(3):Q(4) ratios in the biosilica deposits of the diatoms, quantitative (29)Si MAS NMR experiments were performed. This analysis did not reveal any differences regarding the molecular architecture of the silica (i.e. the degree of condensation of the SiOH units (2 identical with SiOH --> identical with Si-O-Si identical with + H(2)O)) from the different diatom species. However, complete cells showed significantly smaller Q(4):Q(3) ratios (1.8-1.9) than extracted cell walls (2.5-2.8), indicating the existence of intracellular pools of less condensed silica. 相似文献
13.
《Polyhedron》1986,5(3):695-701
New dialkylamido compounds of cadmium have been prepared and their physical and spectral properties studied. Adducts of Cd[N(SiMe3)2]2 with nitrogen donors have also been prepared and studied. Multinuclear NMR spectroscopy (113Cd, 29Si and 13C) has been used but no simple correlation of chemical shifts has been found except the downfield shifts for the 113Cd resonances accompanying an increae in coordination number from two of three. 相似文献
14.
V. V. Sharutin M. A. Ivanov A. V. Gerasimenko A. V. Ivanov A. P. Pakusina O. N. Antsutkin W. Forsling G. Gröbner 《Russian Journal of Coordination Chemistry》2006,32(6):387-396
Crystalline tetraphenylantimony and tetratolylantimony complexes with N,N-dialkyldithiocarbamate ligands [Sb(C6H5)4(S2CNR2)] (R = CH3, C2H5, and C3H7 and R2 = (CH2)6) were synthesized by ligand exchange reactions and studied by 13C and 15N CP/MAS NMR spectroscopy. X-ray diffraction analysis revealed that the complex [Sb(n-CH3-C6H4)4{S2CN(C3H7)2}] exists as the single molecular form, while [Sb(C6H5)4{S2CN(CH2)6}] exists as two molecular conformers. The 13C and 15N signals were assigned to the positions of the atoms in the isomeric structures [Sb(C6H5)4{S2CN(CH2)6}] in terms of different degrees of double bonding in the formally single =N-C(S)S-bond. 相似文献
15.
A. V. Ivanov W. Forsling M. Kritikos O. N. Anzutkin A. Larsson F. A. Zhukov Z. F. Yusupov 《Doklady Chemistry》2000,375(1-3):236-241
16.
A. V. Ivanov E. V. Korneeva A. V. Gerasimenko W. Forsling 《Russian Journal of Coordination Chemistry》2005,31(10):695-707
The structures and spectroscopic properties of nickel(II), zinc(II), and copper(II) complexes with dibutyl- and diisobutyldithiocarbamate were studied by EPR and 13C and 15N CP/MAS NMR spectroscopy and X-ray diffraction analysis. According to the EPR data, copper(II) forms mononuclear [63/65Cu{S2CNR2}2] and heterobinuclear complexes [63/65CuZn{S2CNR2}4] under magnetic dilution conditions. The isomeric forms of nickel(II) and zinc(II) diisobutyldithiocarbamates were detected by 13C and 15N NMR spectroscopy. The crystalline zinc(II) diisobutyldithiocarbamate was found to have a unique structural organization with alternating mononuclear [Zn{S2CN(i-C4H9)2}2] and binuclear molecular forms [Zn2{ S2CN(i-C4H9)2}4] in the 1 : 1 ratio. 相似文献
17.
A. A. Panasenko E. C. Gorincioi A. N. Aricu E. A. Barcari K. Deleanu P. F. Vlad 《Russian Chemical Bulletin》2004,53(12):2700-2705
One- and two-dimensional homo- and heteronuclear correlation proton, carbon, proton—proton, and proton—carbon NMR spectra of fifteen drimanic sesquiterpenoids: 11,12-dibromodrima-5,8-dien-7-one, drim-8-en-7-one, 11-hydroxydrim-8-en-7-one, 11,12-dihydroxydrim-8-en-7-one, 11-hydroxy-11,12-epoxydrim-8-en-7-one, 11-hydroxy-11,12-epoxydrim-8-en-7-one, 8,9-epoxydriman-7-one, 8,9-epoxydriman-7-ol, 11,12-diacetoxydrim-8-en-7-ol, drimane-7,8,11-triol, 7,8-isopropylidenedioxydriman-11-al, 9, 11-dihydroxydrim-7-en-6-one, drimane-7,8,9-triol, drimane-7,8,11-triol, and drim-8-ene-7,11,12-triol were studied. The proton and carbon chemical shifts were assigned.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2589–2594, December, 2004. 相似文献
18.
G. A. Kostin A. O. Borodin S. V. Tkachev N. V. Kuratieva 《Journal of Structural Chemistry》2011,52(5):887-891
Based on the 31P NMR data, equilibriums in the [RuNO(NO2)4OHZn(TPPO)3]-Py system are quantitatively described, and equilibrium constants of dissociation of the initial complex and organic ligand
substitution are determined. The stability of heterometallic complexes is found to increase in passing from TPPO to pyridine.
The mixed ligand [RuNO(NO2)4OHZn(TPPO)2Py] complex is structurally characterized, and it is shown that the TPPO molecule in the trans-position to the μ2-bridging hydroxo group is substituted first. 相似文献
19.
V. I. Volkov E. V. Volkov S. V. Timofeev E. A. Sanginov A. A. Pavlov E. Yu. Safronova I. A. Stenina A. B. Yaroslavtsev 《Russian Journal of Inorganic Chemistry》2010,55(3):318-324
Water self-diffusion and ion mobilities in various ionic forms (H+, Li+, Na+, Rb+, Cs+, and Ba2+) of perfluorinated sulfocationic membranes MF-4SK were studied by NMR and impedance spectroscopy. When degrees of hydration
are low, the self-diffusion coefficients of water and ionic conductivities are considerably affected by the water content
of the membrane. The self-diffusion coefficients decrease in the order H+ > Ba2+ > Cs+ > Rb+ > Na+ > Li+, whereas the ion mobility decreases in the order H+ > Li+ > Na+ > Cs+ > Ba2+. 相似文献
20.
L. A. Baltina O. Kunert A. A. Fatykhov R. M. Kondratenko L. V. Spirikhin L. A. BaltinaJr. F. Z. Galin G. A. Tolstikov E. Haslinger 《Chemistry of Natural Compounds》2005,41(4):432-435
Resonances for protons and C atoms in the 1H and 13C NMR spectra of glycyrrhizic acid and its esters were assigned using high-resolution 1H (600 MHz) and 13C (150 MHz) NMR methods.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 347–350, July–August, 2005. 相似文献