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61.
N. Aggarwal B. Singh A. K. Bhati Renu Bala S. C. Bedi H. S. Hans 《Hyperfine Interactions》1983,13(1-3):271-274
Integral perturbed angular correlation technique has been used to measure the internal hyperfine magnetic fields at Hf nuclei in Fe, Co and Ni matrices. These represent a consistent set of measurements with diffused sources. The 9+/2 (208 keV) 9?/2 (113 keV) 7?/2 cascade in the decay of177Lu→177Hf was used for measurements. The results obtained are: $$\begin{gathered} H_{Fe}^{Hf} = - 266 \pm 47 kG, \hfill \\ H_{Co}^{Hf} = - 116 \pm 18 kG, \hfill \\ H_{Ni}^{Hf} = - 118 \pm 26 kG. \hfill \\ \end{gathered} $$ These measurements are compared with previous results and discussed in terms of methods of source preparation. 相似文献
62.
Lobana TS Sharma R Sharma R Mehra S Castineiras A Turner P 《Inorganic chemistry》2005,44(6):1914-1921
Reaction of copper(I) iodide with pyridine-2-thione (2-SC5H4NH) and 1,2-bis(diphenylphosphino)ethane (dppe) in a CH3CN-CHCl3 mixture yielded a triangular cluster, [Cu3I3(mu2-P,P-dppe)3 (eta1-SC5H4NH)], 1. Similar reaction with 2-SC5H4NH and a series of diphosphanes, Ph2P-X-Ph2P {X = -CH2- (dppm), -(CH2)3- (dppp), -(CH2)4- (dppb), -CH=CH- (dppen)}, gave a novel iodo-bridged hexanuclear Cu(I) linear polymer,{Cu6(mu3-SC5H4NH)4 (mu2-SC5H4NH)2 (I4)(mu-I)2-}n x 2nCH3CN, 2. Reactions of copper(I) iodide/copper(I) bromide with 1,3-imidazolidine-2-thione (SC3H6N2) in a CH3CN-CHCl3 mixture yielded hexanuclear Cu(I) linear chain polymers, [{Cu6(mu3-SC3H6N2)2 (mu2-SC3H6N2)4X2 (mu-X)4}n] (X = Br, 4; I, 5). In compound 1, two iodide atoms and one dppe form the dinuclear Cu(mu2-I)2 (mu2-dppe)Cu core, and two dppe ligands bridge this core with the third Cu(I) center coordinated to 2-SC5H4NH via the S atom. The chain polymer 2 has a centrosymmetric hexanuclear central core, Cu6S6I4 (mu-I)2--, formed by dimerization of six-membered trinuclear motifs, Cu3(mu2-SC3H6N2)3I3 via (mu3-S) bonding modes of the thione ligand, and has four terminal and two bridging iodine atoms in trans-orientations. Linear chains are separated by the nonbonded acetonitrile molecules. In 4 and 5, three copper(I) bromide or copper(I) iodide moieties and three SC3H6N2 ligands combined via bridging S donor atoms to form the six-membered trinuclear Cu3(mu2-SC3H6N2)3I3 cores which polymerized via S and X atoms in a side-on fashion to form linear chain polymers, [{Cu6(mu3-SC3H6N2)2 (mu2-SC3H6N2)4X2(mu-X)4}n]. The (mu3-S) modes of bonding of neutral heterocyclic thioamides are first examples, as are trinuclear cluster and linear polymers rare examples in copper chemistry. 相似文献
63.
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
64.
Renu Mahajan Himani Nandedkar Sheeba Daniel 《Molecular Crystals and Liquid Crystals》2013,570(1):697-707
Abstract The present work deals with synthesis of two homologous series possessing ester and amide linkage and a large lateral aryl substituent. The large lateral group is attached to the main molecule through an amide linkage. Mesogenic amides are rare even when the amide linkage is present in the main molecular framework. However, in the present work the compounds containing amide linkage in lateral moiety also exhibit mesophases of high thermal stability. 相似文献
65.
Zbigniew J. Witczak Renu Chhabra Dina Boryczewski 《Journal of carbohydrate chemistry》2013,32(4-5):543-553
ABSTRACT β-(1→2)-2,3-Dideoxy-2-C-acetamidomethyl-2-S-thiodisaccharides were synthesized in four steps by a stereoselective base catalyzed Michael addition reaction of 1-thiosugars to α-nitroalkene 4a, a new chiral synthon from levoglucosenone. It was followed by the reduction of the nitro group with a sodium borohydride/cobalt chloride complex and the hydrolytic opening of the 1,6-anhydro ring. 相似文献
66.
67.
Butler F Fu X Kalbfleisch G Lambrecht M Ross WR Skubic P Snow J Wang P Bortoletto D Brown DN Dominick J McIlwain RL Miao T Miller DH Modesitt M Schaffner SF Shibata EI Shipsey IP Battle M Ernst J Kroha H Roberts S Sparks K Thorndike EH Wang C Sanghera S Skwarnicki T Stroynowski R Artuso M Goldberg M Horwitz N Kennett R Moneti GC Muheim F Playfer S Rozen Y Rubin P Stone S Thulasidas M Yao W Zhu G Barnes AV Bartelt J Csorna SE Egyed Z Jain V Sheldon P Akerib DS Barish B Chadha M Cowen DF Eigen G 《Physical review letters》1992,69(14):2041-2045
68.
Racemic alkyl-2-hydroxy-4-arylbut-3-ynoates were deracemized to the (S)-alkyl-2-hydroxy-4-arylbut-3-ynoates in excellent enantiomeric excesses (up to >99%) and good isolated yields (up to 81%) with the biocatalyst Candida parapsilosis ATCC 7330. The absolute configuration of the resulting enantiomer was assigned by 1H NMR using Mosher’s method. 相似文献
69.
Alka Chadha Swaroop Nandan Bora 《Stochastics An International Journal of Probability and Stochastic Processes》2018,90(5):663-681
The paper is mainly concerned with a class of neutral stochastic fractional integro-differential equation with Poisson jumps. First, the existence and uniqueness for mild solution of an impulsive stochastic system driven by Poisson jumps is established by using the Banach fixed point theorem and resolvent operator. The exponential stability in the pth moment for mild solution to neutral stochastic fractional integro-differential equations with Poisson jump is obtained by establishing an integral inequality. 相似文献
70.
Whole cells of Candida parapsilosis ATCC 7330 were used for the resolution of N-acetyl amino acid esters. Excellent enantioselectivities (E = 40 to >500) were achieved for the resolution of N-protected protein and non-protein amino acid esters giving good yields (28–50%) and high enantiomeric excesses (up to >99%) for both enantiomers. 相似文献