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81.
Two organic-inorganic hybrid compounds, Ga2(4,4′-bpy)(PO4)2, 1, and Ga2(4,4′-bpy)(AsO4)2, 2, have been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction. The two compounds are isostructural and crystallize in the triclinic space group (No. 2) with a=4.9723(9) Å, b=5.770(1) Å, c=11.812(2) Å, α=78.268(3)°, β=89.159(3)° γ=88.344(3)°, V=331.7(2) Å3, Z=1, and R1=0.0377 for 1, and a=5.1111(7) Å, b=5.9327(8) Å, c=11.788(2) Å, α=79.497(2)°, β=88.870(2)°, γ=88.784(2)°, V=351.3(2) Å3, and R1=0.0264 for 2. The structure consists of neutral sheets of GaXO4 (X=P or As) which are pillared through 4,4′-bipyridine ligands. Each oxide layer, which is formed only by four-membered rings, is constructed from corner-sharing GaO4N trigonal bipyramids and XO4 tetrahedra. The title compounds are two of the few examples in which the gallium atoms are exclusively five-coordinate. 相似文献
82.
Michael I. Bruce Michael Schulz Brian W. Skelton Allan H. White 《Journal of Cluster Science》2000,11(1):79-86
Addition of aqueous HCl to Ru5(
3-C=CH2)(-SMe)2(-PPh2)2(CO)10 afforded the structurally characterized carbyne complex Ru5(
3-SMe)(
3-CMe)(-Cl)(-SMe)(-PPh2)2(CO)9, formed by addition of H to the vinylidene ligand; a Cl atom bridges an Ru–Ru bond. 相似文献
83.
Summary Gauss elimination applied to ann×n matrixA in floating point arithmetic produces (if successful) a factorization
which differs fromA by no more than
, for some of ordern times the unit roundoff. IfA is totally positive, then both computed factors
and
are nonnegative for sufficiently small unit roundoff and one obtains pleasantly small bounds for the perturbation inA which would account for the rounding errors committed in solvingAx=b forx by Gauss eliminationwithout pivoting. It follows that the banded linear system for the B-spline coefficients of an interpolating spline function can be solved safely by Gauss elimination without pivoting.Sponsored by the United States Army under Contract No. DAAG29-75-C-0024 and the National Science Foundation under Grant No. MPS72-00381 A01. 相似文献
84.
85.
Abstract A new type of fire-retardant polymer has been formed by modification of dispersions of chitosan [(1,4)-2-amino-2-deoxy-β-D-glucan] in inert organic liquids using hexachlorocyclotriphos-phazene or octachlorocyclotetraphosphazene as well as mixtures thereof in the presence of an acid acceptor. The reaction products are essentially insoluble and infusible, contain up to 8% phosphorus, and have IR spectra indicative of exclusive reaction at the amino groups of the aminopolysaccharide. The influence of reaction conditions on the characteristics of the products is discussed. 相似文献
86.
Florence Mauger Jean‐Claude Tabet Ivo G. Gut 《Rapid communications in mass spectrometry : RCM》2014,28(13):1433-1443
87.
88.
89.
Hamoud Moustafa A. Allan Karam F. Sanad Wafaa A. Saad Ebtissam A. Mahmoud Mamdoh R. 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(2):647-661
Polyacrylonitrile/ferrocyanide composite incorporated with cetrimonium bromide (PFICB) was synthesized and evaluated as a novel bifunctional adsorbent for coremoval of Cs+ and HCrO4?. Results of the reaction time effect showed that adsorption of Cs+ and HCrO4? onto PFICB were rapid processes. The effect of the solution pH in the range 2.5–10 revealed that PFICB had the ability to simultaneously remove Cs+ and HCrO4?. The maximum adsorption capacity of PFICB was found to be 41.79 mg/g for Cs+ and 19.39 mg/g for HCrO4?. These values were compared with those reported in literature using other adsorbents.
相似文献90.
Sumit Dadhwal Arnold Lee Shailesh K. Goswami Sarah Hook Allan B. Gamble 《Journal of polymer science. Part A, Polymer chemistry》2021,59(7):646-658
Self-immolative aryl azides can react with trans-cyclooctenes (TCO), triphenylphosphines or hydrogen sulfide (H2S) to activate prodrugs, imaging probes and drug delivery systems. To date, the synthesis of polymers containing these aryl azide self-immolative linkers and their reactivity with a strained alkene (i.e., in a bioorthogonal reaction) has not been explored. Also, due to the instability of aryl azides towards light and high temperatures, the polymerization methods compatible with aryl azides are limited. Through systematic investigation of the reversible addition-fragmentation chain transfer (RAFT) and atom transfer radical polymerization (ATRP) methods, a self-immolative PEG-aryl azide block copolymer (PEG45-b-ABOC28 2 ) and a non-responsive 4-fluoroaryl block copolymer (PEG45-b-FBOC24 3 ) was prepared. ATRP provided the desired polymers in a highly controlled manner, whereas the RAFT conditions led to higher levels of aryl azide polymer degradation. The ATRP derived polymers 2 and 3 were formulated into nanoparticles of approximately 200 nm diameter, and particle triggering was demonstrated by the [3+2]-cycloaddition reaction of TCO with PEG45-b-ABOC28 2 in solution (pure polymer) and as a formulated nanoparticle. Preliminary in vitro cell viability studies suggested that the stimuli-responsive aryl azide polymers/nanoparticles are not cytotoxic up to 200 μg/ml concentrations. 相似文献