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971.
The thermal degradation of a series of 1,1,2,2-tetraaryl-1,2-ethanediols has been examined using thermogravimetry (TG) and
gas chromatography/mass spectrometry (GC/MS). These compounds are smoothly converted to the corresponding diaryl ketone and
diaryl carbinol, i.e., the compounds undergo disproportionation arising from homolytic cleavage of the central carbon–carbon
bond. Presumably, cleavage of the carbon–carbon bond generates a radical pair which disproportionates to provide the observed
products. 相似文献
972.
Hyun Ho Lee 《Journal of Functional Analysis》2011,260(1):135-145
In this paper we generalize the notion of essential codimension of Brown, Douglas, and Fillmore using KK-theory and prove a result which asserts that there is a unitary of the form ‘identity + compact’ which gives the unitary equivalence of two projections if the ‘essential codimension’ of two projections vanishes for certain C∗-algebras employing the proper asymptotic unitary equivalence of KK-theory found by M. Dadarlat and S. Eilers. We also apply our result to study the projections in the corona algebra of C(X)⊗B where X is [0,1], (−∞,∞), [0,∞), and [0,1]/{0,1}. 相似文献
973.
974.
975.
Manesh Kalayil Manian Gopalan Anantha Iyengar Kwang‐pill Lee Nam Hee Kim Komathi Shanmugasundaram Seong Ho Kang 《Journal of polymer science. Part A, Polymer chemistry》2010,48(20):4537-4546
Poly(trimethoxy silylpropylaniline), a nanoporous (pore diameter of 2.4 nm), electroactive (stable reversible redox characteristics), electrochromic (yellow at ?0.10 V, blue green at +0.50 V, and dark green at +0.70 V), and pH‐sensitive, silica–polyaniline (PANI) hybrid material (designated as KGM‐1) has been synthesized in powder form by a simple one‐pot chemical synthesis as well as a “thin nanolayered film” by cyclic voltammetry. High‐resolution transmission image of KGM‐1 informs that the particles are spherical, with diameters in the range of 0.5–1.5 μm. X‐ray diffraction pattern of pristine KGM‐1 confirms the combined presence of ordered silica network and PANI chains. The surface area of calcined KGM‐1 is 40 m2/g (~15 times higher than KGM‐1), and the average pore size is 2.4 nm. The N2 adsorption features also inform that PANI is present as a uniform layer within the pores of silica and because of that the silica pores are not completely blocked. The reversible redox transitions in PANI units and nanoporosity of KGM‐1 are effectively used for the electro‐driven loading/release of DNA or adenosine 5′‐triphosphate. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
976.
977.
978.
979.
3‐Bromoallyl alcohols are carbonylatively cyclized under carbon monoxide pressure in toluene in the presence of a catalytic amount of Pd(OAc)2 and PPh3 along with Na2CO3 to give furan‐2(5H)‐ones in good yields. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
980.
Pei‐Hsuan Wang Ming‐Shou Ho Sheng‐Hsiung Yang Kuei‐Bai Chen Chain‐Shu Hsu 《Journal of polymer science. Part A, Polymer chemistry》2010,48(3):516-524
Three polyfluorene derivatives which have oxetane‐containing phenyl group at C‐9 position were synthesized via the palladium‐catalyzed Suzuki‐coupling reaction. The synthesized polymers PFB, PFG, and PFR emit blue, green, and red light, respectively. A double‐layer device with the configuration of ITO/PEDOT/polymer/Ca/Al using PFB as the active layer showed a threshold voltage of 5 V, a maximum brightness of 2030 cd/m2, and a maximum current efficiency of 0.35 cd/A. Using PFG as the active layer, the device exhibited a threshold voltage of 6 V, a maximum brightness of 6447 cd/m2, and a maximum current efficiency of 1.27 cd/A. Using PFR as the active layer, the device showed a threshold voltage of 4 V, a maximum brightness of 2135 cd/m2, and a maximum current efficiency of 0.16 cd/A. Better electroluminescent performance was also found based on different design of device structures. Due to photo‐crosslinking property of oxetane groups, the UV‐exposed thin films are insoluble in common organic solvents. A device comprised of blue, green, and red‐emissive pixels was successfully fabricated by spin‐coating and photo‐lithographic processes. In addition, a white light‐emitting device with CIE coordinate of (0.34, 0.33) was achieved by blending PFR into a host material PFB as the active layer. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 516–524, 2010 相似文献