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41.
Crystal structures of a series of organic–inorganic hybrid gold iodide perovskites, formulated as A2[AuII2][AuIIII4] [A=methylammonium (MA) ( 1 ) and formamidinium (FA) ( 2 )], A′2[I3]1−x[AuII2]x[AuIIII4] [A′=imidazolium (IMD) ( 3 ), guanidinium (GUA) ( 4 ), dimethylammonium (DMA) ( 5 ), pyridinium (PY) ( 6 ), and piperizinium (PIP) ( 7 )], systematically changed depending on the cation size. In addition, triiodide (I3) ions were partly incorporated into the AuI2 sites of 3 – 7 , whereas they were not incorporated into those of 1 and 2 . Such a difference comes from the size of the organic cation. Optical absorption spectra showed characteristic intervalence charge-transfer bands from AuI to AuIII species, and the optical band gap increased as the size of the cation became larger.  相似文献   
42.
Mesoporous core–shell nanostructures with controllable ultra-large open channels in their nanoshells are of great interest. However, soft template-directed cooperative assembly to mesoporous nanoshells with highly accessible pores larger than 30 nm, or even above 50 nm into macroporous range, remains a significant challenge. Herein we report a general approach for precisely tailored coating of hierarchically macro-/mesoporous polymer and carbon shells, possessing highly accessible radial channels with extremely wide pore size distribution from ca. 10 nm to ca. 200 nm, on diverse functional materials. This strategy creates opportunities to tailor the interfacial assembly of irregular mesostructured nanounits on core materials and generate various core–shell nanomaterials with controllable pore architectures. The obtained Fe,N-doped macro-/mesoporous carbon nanoshells show enhanced electrochemical performance for the oxygen reduction reaction in alkaline condition.  相似文献   
43.
We study the infrared emission at 1.54 μm of an organolanthanide complex, Er(III)-tetraphenylporphyrin [Er(TPP)acac], both as a result of direct optical excitation and via energy transfer from host π-conjugate polymers of type poly(arylene–ethynylene) [PAE]. In the first case, the emission of the neat complex is characterized in inert transparent materials and a value of the quantum yield at 1.54 μm φIR=4×10−4 is measured. Then, fluorescence resonance transfer is investigated in blends of Er(TPP)acac with PAEs by monitoring the quenching of the polymer fluorescence along with the enhancement of both the visible emission of the ligand and the near-infrared band of Er3+. These different procedures allow a detailed analysis of the transfer efficiency within a specific implementation of the Förster model for polymeric donors. The experimental values of the critical radius R0, ranging from 1.3 to 2.5 nm for the different blends, are in good agreement with theory for a wide interval of the physical and spectroscopic parameters. This suggests that other mechanisms for excitation transfer do not play a significant role in these materials.  相似文献   
44.
The crystal structure of [N(CH3)4]3[As2Cl9] is determined at 293 K. It crystallizes in trigonal space group P31c: a = 9.2199(8), c = 21.065(3)Å, Z = 2, R1 = 0.0505, wR2 = 0.1283. The crystal is built of the discrete bioctahedral [As2Cl9]3— anions and the deformed tetramethylammonium cations. A structural phase transition in [N(CH3)4]3[As2Cl9] is detected by the DSC and dilatometric techniques at 146/151 K (on cooling/heating). Dielectric relaxation studies in the frequency range 75 kHz — 5 MHz indicate reorientations of the tetramethylammonium cations within the high temperature phase. Optical observations show the existence of the ferroelastic domain structure below 146 K. The possible mechanism of phase transition is discussed on the basis of the presented results.  相似文献   
45.
The results of comparative thermal analysis (TG-DTG-DTA-DSC) of the thermal decomposition of hexamminecobalt(III) chloride in air atmosphere are reported. The kinetics and mechanism of the thermal decomposition, the process enthalpy and the variation in specific thermal capacity of the solid product reaction with temperature were determined.  相似文献   
46.
Two new polyacid derivative ligands of thienyl-substituted terpyridine analogues, N,N,N1,N1-[4′-(2?-thienyl)-2,2′:6′,2″-terpyridine-6,6″-diyl]bis(methylenenitrilo) tetrakis(acetic acid) (TTTA) and N,N,N1,N1-[2,6-bis(3′-aminomethyl-1′-pyrazolyl)-4-(2″-thienyl)pyridine] tetrakis(acetic acid) (BTTA), were synthesized, and the luminescence properties of their Eu3+ and Tb3+ chelates were investigated. The Eu3+chelates of the two ligands are strongly luminescent having luminescence quantum yields of 0.150 (TTTA-Eu3+) and 0.114 (BTTA-Eu3+), and lifetimes of 1.284 ms (TTTA-Eu3+) and 1.352 ms (BTTA-Eu3+), whereas their Tb3+ chelates are weakly luminescent. The TTTA-Eu3+ chelate was used for streptavidin (SA) labeling, and the labeled SA was used for time-resolved fluoroimmunoassay of insulin in human sera. The method gives the detection limits of 33 pg ml−1.  相似文献   
47.
迄今未见任何稀土氨基酸络合物的ESR波谱报道,本文在合成Gd3+分别与甘氨酸、β-丙氨酸、谷氨酸、天冬氨酸和天冬酰胺五种氨基酸络合物的基础上,测定了不同温度下,水溶液、粉末及分子筛吸附样品的ESR谱,讨论了络合物中晶体场强,对称性及成键特性。  相似文献   
48.
Graft polymerization initiated by diperiodatocuprate(III) complex (Cu(III)) initiator was found to be an effective and convenient method for graft polymerization of vinyl monomers onto macroporous polyacrylamide gels, the so‐called cryogels (pAAm‐cryogels). The effect of time, temperature, monomer and initiator concentration during the graft polymerization in aqueous and aqueous‐organic media was studied. The graft polymerization of water‐soluble monomers as [2‐(methacryloyloxy)ethyl]‐trimethylammonium chloride, 2‐hydroxyethyl methacrylate, N‐isopropylacrylamide, and N,N‐dimethylacrylamide proceeds with higher grafting yield in aqueous medium, as compared with that in aqueous‐organic media. Graft polymerization in aqueous‐organic media such as water–DMSO solutions allows grafting of water‐insoluble monomers such as glycidyl methacrylate and Ntert‐butylacrylamide with high grafting degrees of 100 and 410%, respectively. It was found that the deposition of initiator on the pore surface of cryogels promoted graft polymerization by facilitating the formation of the redox couple Cu(III)‐acrylamide group. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1952–1963, 2006  相似文献   
49.
This review narrates the electron transfer reactions of various nickel(III) and nickel(IV) complexes reported during the period 1981 until today. The reactions have been categorized mainly with respect to the type of nickel complexes. The reactivity of nickel(III) complexes of macrocycles, 2,2′-bipyridyl and 1,10-phenanthroline, peptides and oxime–imine, and of nickel(IV) complexes derived from oxime–imine, oxime and miscellaneous ligands with various organic and inorganic electron donors have been included. Kinetic and mechanistic features associated with such interactions have been duly analyzed. The relevance of Marcus cross-relation equations in the delineation of the electron transfer paths has also been critically discussed.  相似文献   
50.
关于Fe(Ⅲ)-邻菲罗啉(phen)溶液的光化学还原现象的记载可追溯到十九世纪末。  相似文献   
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