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11.
Enrique J. Baran 《Monatshefte für Chemie / Chemical Monthly》1979,110(2):297-300
Mean amplitudes of vibration for various octahedral complex compounds of the typeLnCl6
3– andLnBr6
3– (withLn=Nd, Eu, Gd, Dy, Er, and Yb) have been calculated, at different temperatures, using known spectroscopic data. The results are briefly discussed and it is found that theLn–Cl andLn–Br amplitude values are highly characteristic. 相似文献
12.
I NQR and spectroscopic investigation of impurity-doped and mixed lithium iodate Li1−xHxIO3 crystals
A. Barabash T. Gavrilko K. Eshimov J. Baran H. Ratajczak 《Journal of Molecular Structure》2004,708(1-3):113-116
The 127I NQR, IR absorption and Raman spectra of impurity-doped and mixed lithium iodate Li1−xHxIO3 crystals grown from water solutions with different LiIO3/HIO3 ratios were investigated depending on the content of the impurity hydrogen x. The NQR results suggested that, at small concentration of doping iodic acid x<0.22, the lattice dynamics of the crystal grown from water solution changes significantly though the crystal retains hexagonal symmetry. Spectroscopic studies are compatible with average hexagonal symmetry of the grown doped crystals. From the results of Raman studies at room temperature and 100 K, the concentration range of hydrogen dopant 0.22<x<0.36 was found where disordered solid solution crystals Li1−xHxIO3 are formed. 相似文献
13.
I.R. Spectra of the Phases A B Te3O8 (A = Fe, In, Sc; B = Nb, Ta) and UTe3O9 The infrared spectra of the title compounds have been recorded and discussed in comparison to formerly investigated MIVTe3O8 phases. The spectrum of UTe3O9 (synthetic cliffordite) confirms the presence of uranyl groups and the structural relation of this compound to the fluorite. 相似文献
14.
Nicolaou KC Baran PS Zhong YL Barluenga S Hunt KW Kranich R Vega JA 《Journal of the American Chemical Society》2002,124(10):2233-2244
The discovery and development of the o-iodoxybenzoic acid (IBX) reaction with certain unsaturated N-aryl amides (anilides) to form heterocycles are described. The application of the method to the synthesis of delta-lactams, cyclic urethanes, hydroxy amines, and amino sugars among other important building blocks and intermediates is detailed. In addition to the generality and scope of this cyclization reaction, this article describes a number of mechanistic investigations suggesting a single electron transfer from the anilide functionality to IBX and implicating a radical-based mechanism for the reaction. 相似文献
15.
We have been studying the problem of heterogeneity of OH groups in zeolites HY for a long time. The heterogeneity was suggested by the shift of the IR band of OH groups restoring upon ammonia desorption and also by the fact that the band of OH groups forming hydrogen bonds was relatively broad (broader than for homogeneous acidic OH). In the present study we present another important argument for heterogeneity: the splitting of the IR band of free OH and OD groups in a zeolite of Si/Al=8.3 dealuminated by (NH4)2SiF6 treatment. Such a splitting is the best seen in low temperature spectra of OD groups. We found less acidic 3640 cm−1 (AlO)(SiO)2SiO1HAl(OSi)3 and more acidic 3625 cm−1 (SiO)3SiO1HAl(OSi)3 groups. The presence of these two kinds of hydroxyls corresponds to the presence of Si(2Al) and Si(1Al), respectively, detected in 29Si MAS NMR spectra. We also found a small amount of strongly acidic 3599 cm−1 hydroxyls interacting with extraframework Al species. 相似文献
16.
L’ubica Triščíková Ivan Potočňák Jozef Chomič Peter Baran 《Transition Metal Chemistry》2006,31(4):504-515
The new mixed-valence mixed-metal complex Cu(py)6Cu2Ag2(CN)6 (py = pyridine) possesses a three dimensional polymeric crystal structure. The Cu(I) atom is tetrahedrally coordinated by
two nitrogen atoms of pyridine molecules, by one nitrogen atom of the dicyanoargentate anion and by one carbon atom of the
cyano group. Both the dicyanoargentate anion and the cyano group bridge the Cu(I) atom with neighboring Cu(II) atoms. These
are hexacoordinated in the form of an elongated tetragonal bipyramid. The equatorial plane is formed by two nitrogen atoms
from two pyridine molecules and two nitrogen atoms from bridging cyano groups. Axial positions are occupied by nitrogen atoms
of the bridging [Ag(CN2]− anions. Correlation between structures of the title compound and seven other dicyanoargentates with their i.r. spectra has
been studied. The coordination mode of [Ag(CN2]− anions in compounds Cu8-xAgx(tn)3(CN)10 x = 0.25, Cu(3-Mepy)2Ag2(CN)4, Cu(py)2Ag2(CN)4 and Cu(py)4Ag2(CN)4 (tn is 1,3-diaminopropane, 3-Mepy is 3-methylpyridine) is predicted based on this correlation. 相似文献
17.
A.N. Nesmeyanov D.V. Zagorevskii Yu.S. Nekrasov V.F. Sizoi V.M. Postnov A.M. Baran E.I. Klimova 《Journal of organometallic chemistry》1979,169(1):77-81
The main processes of the electron-impact induced fragmentation of the ferrocenyl and cymantrenyl analogues of chalcones RCOCH=CHR′ (R, R′ = C5H4FeC5H5, C5H4Mn(CO)3, or aryl) involve a cleavage of the metalligand bond. A “chalcone” mode of fragmentation is weakly pronounced, due to the fact that the positive charge is localized preferably on the metal atom. 相似文献
18.
E. J. Baran 《Monatshefte für Chemie / Chemical Monthly》1972,103(6):1684-1690
Zusammenfassung An Hand der Pulverdiagramme wurden die Gitterkonstanten von Ca5(VO4)3Br, Sr5(VO4)3Br und Ba5(VO4)3Br ermittelt. Alle drei Verbindungen kristallisieren hexagonal und besitzen die Apatitstruktur. Mit den erhaltenen Daten werden einige kristallchemische Betrachtungen sowie Vergleiche mit anderen verwandten Verbindungen gemacht.
7. Mitt. der Reihe Orthovanadate und verwandte Verbindungen; 6. Mitt.:E. J. Baran undP. J. Aymonino, Z. anorg. allgem. Chem.390, 77 (1972). 相似文献
Crystallographic data of some vanadium bromoapatites
The unit cell parameters of Ca5(VO4)3Br, Sr5(VO4)3Br and Ba5(VO4)3Br, calculated by means of powder diagramms, are given. The compounds belong to the hexagonal system and crystallize with the apatite structure. With the obtained data, some comparisons are made and some aspects of the crystal chemistry of these and related compounds are discussed.
7. Mitt. der Reihe Orthovanadate und verwandte Verbindungen; 6. Mitt.:E. J. Baran undP. J. Aymonino, Z. anorg. allgem. Chem.390, 77 (1972). 相似文献
19.
A set of seven bituminous coal chars has been characterised by IR spectroscopy (FTIR), thermogravimetry (TG) and elemental analysis. FTIR study provided suitable information to establish differences between coal samples according to their chemical compositions. The reactivity of these samples was also studied and correlated with the coal parameters of mean vitrinite reflectance, fuel ratio and H/C ratio. The data suggest that reactivity as determined can be correlated with the mean vitrinite reflectance, fuel ratio and H/C ratio (0.90). The order of reactivity of samples were; Amasra (S1) (R m= 0.65)>Azdavay (S4) (R m=0.99)»Armutcuk (S2) (R m=0.81)»Acenta (S3) (R m=0.92)>Ac2l2k (S6) (R m=1.11) Cay (S5) (R m=1.03)>Sogutozu (S7) (R m=2.14). 相似文献
20.
Pressurised liquid extraction (PLE) technique was used for the simultaneous extraction of phenylureas, triazines and chloroacetanilides and some of their metabolites from soils. Extractions were performed by mixing 15 g of dried soil with 30 mL of acetone under 100 atm at 50 degrees C, during 3 min and with three PLE cycles. Prior to the analysis of naturally contaminated soils, each of the five representative soil matrices used as blanks (of different depths) was spiked in triplicate with standards of each parent and degradation compound at about 10, 30 and 120 microg/kg. For each experiment, isoproturon-D6 and atrazine-D5 were used as surrogates. Analysis of phenylureas and metabolites of triazines and phenylureas was carried out by reversed phase liquid chromatography/mass spectrometry (LC-MS) and LC-MS/MS in the positive mode. Gas chromatography (GC)/ion trap mass spectrometry was used in the MS/MS mode for the parent triazines and chloroacetanilides. The average extraction recoveries were above 85%, except for didesmethyl-isoproturon, and quantification limits were between 0.5 and 5 microg/kg. The optimised multi-residue method was applied to soils and solids below the root zone, sampled from agricultural plots of a small French hydrogeological basin. 相似文献