共查询到19条相似文献,搜索用时 125 毫秒
1.
配合物PdCl2[(PPh2)2CHCl]的合成、结构及反应机理 总被引:2,自引:2,他引:0
合成了新配合物PdCl2[(PPh2)2CHCl],用核磁、红外光谱、元素分析等表征了其结构,X-rax衍射确定了单晶结构.应用电子顺磁共振-自旋捕获(EPR-ST)对技术研究了其反应的机理.捕获到PPh2及含碳自由基中间体,提出了反应机理. 相似文献
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C60Pd(Ph2PCH2PPh2)配合物的合成及光电性能研究 总被引:1,自引:0,他引:1
在氮气氛下 ,采用配体取代法 ,即以C60 取代Pd(Ph2 PCH2 PPh2 ) 2 中一个Ph2 PCH2 PPh2 合成出富勒烯金属配合物C60 Pd(Ph2 PCH2 PPh2 ) ,采用元素分析、红外光谱、紫外可见光谱、光电子能谱以及X射线粉末衍射等手段对产物进行表征 .同时研究了产物的光电性能、氧化还原性能及热稳定性能 .光伏效应研究结果表明 ,产物具有优良的光电转化性能 ,尤其是在BQ/H2 Q介质电对中 ,光生电压最大达到 174mV ;当C60 Pd(Ph2 PCH2 PPh2 )薄膜厚度为 1μm时 ,光伏效应值最大 . 相似文献
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研究了氧缺陷YBa2Cu3Ox(x=6.33-6.94)超导体在300K和77K下的正电子寿命谱,利用两态捕获模型计算了局域电子密度ne和空位浓度Cv的变化,发现了存在于由氧缺陷导致正交-四方结构转变区域的异常变化和结构不稳定性,讨论了相应的正电子漂没特征以及与超导电性之间的关联。 相似文献
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在120K至470K的温区内,测量了脉冲激光沉积YBa2CuO7-x薄膜的正电子寿命的温度依赖关系.实验结果表明,除块材中存在的正电子深捕获中心外,超导外延膜中还存在大量块材中缺乏的正电子浅捕获中心;低温下,深捕获中心所对应的缺陷有可能扩展成为有效的磁通钉扎中心.浅捕获中心对正电子的束缚能为27meV. 相似文献
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在80K-400K的温区内测量了Y1-xrxBa2CU3O7-δ体系 电子寿命的温度依赖关系,YBa2Cu3O7-δ样品,正电子平均寿命具有明显的温度依赖性;随着Pr的掺入,温度依赖性 ,以致于PrBa2Cu3O7-δ体系的正电子平均寿命不再随温度变化,正电子寿命的温度依赖性可用正电子浅捕获理论加以解释,并由实验数据拟合得出了浅捕获中心的正电子束缚能,文中还讨论了该体系中正电子清捕获中心所对应的缺 相似文献
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用正电子寿命技术研究了高温超导外延薄膜YBa2Cu3O7-x中空位型缺陷的性质.结果表明,空位缺陷的类型与沉积条件无关,缺陷浓度随空气分压的增加或衬底温度的降低而增加.正电子平均寿命的温度依赖关系测量结果指出,当温度在室温以上时,几乎所有的正电子都逃逸出浅捕获中心;当温度高于375K时,必须考虑其退火效应. 相似文献
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应用电子自旋捕获技术(EPR-ST)研究了Pd(OAc)2与有机膦dppm(二,二苯基膦甲烷)及dppe(二,二苯基膦乙烷)在氯代烷中反应生成新奇配合物PdCl2[PPh2CHClPPh2]这一新反应的反应机理,所用捕获剂为PBN和POBN,得到EPR实验谱并进行了模拟.提出了反应机理并进行了讨论.反应经过dppm的均裂、夺氯、夺氢后生成新配体[PPh2CHClPPh2],然后发生配位取代和配位反应,生成新的配合物PdCl2[PPh2CHClPPh2].并对影响反应的因素进行了探讨,溶剂效应在此类自由基反应中起重要作用,其极性对反应的发生影响很大,主要是对过渡态1及2的影响.Pd(OAc)2在反应中既是反应物还是引发剂,在反应中起分子诱导作用. 相似文献
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设计并合成了以2-(2,4-二氟苯基)嘧啶(DFPPM)为主配体的两种新型二嗪铱配合物 (Ph:苯基)和,用核磁共振(NMR)和质谱等方法对其进行了表征,并用紫外-可见吸收光谱和光致发光光谱对其光学性质进行了研究。光致发光光谱结果显示:配合物 的发射峰波长为472 nm和489 nm;而配合物 的发射峰波长为447 nm和472 nm,1931CIE色度坐标为(0.14,0.15),是一种深蓝色磷光材料。以 为客体材料、PVK为主体材料制备了电致发光器件,研究了其电致发光光谱。结果表明,电致发光光谱与光致发光光谱相比有较大程度的红移。 相似文献
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本文对二种新合成的2,3-二羟基萘二钼和四钼多酸有机衍生物[n-Bu)4N]2[Mo2O5(OC10H6O)2](Ⅰ)和[n-Bu)4N]2[Mo4O10(OC10H6O)2(OCH3)2](Ⅱ)进行了红外光谱与核磁共振波谱研究,发现[Mo2O5]^2 中钼氧多桥键的红外振动频率较[Mo4O10(OCH3)2]^2 中钼氧多桥键的红外振动频率红移,而在配合物Ⅱ中2,3-二羟基中芳环的^1H化学位移较配合物Ⅰ中向低场移动。同时还发现含二钼配位中心[Mo2O5]^2 的[Mo2O5(OC10H6O)2]^2-与含四钼配位中心[Mo4O10(OCH3)2]^2 的[Mo4O10(OC10H6O)2(OCH3)2]^2-生成条件的差异仅仅只在反应体系的pH值的微小变化,说明钼多酸有机衍生物阴离子是对体系酸碱度极为敏感的物质。 相似文献
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The synthesis of tetrazoles was achieved via the palladium-catalyzed three component coupling (TCC) reaction; The TCC reaction of malononitrile derivatives, allyl acetate and trimethylsilyl azide proceeds very smoothly under a catalytic amount of Pd(PPh3)4 to give 2-allyltetrazoles, and further the TCC reaction of various activated cyano compounds, allyl methyl carbonate and trimethylsilyl azide proceeds readily under a catalytic amount of Pd2(dba)3 x CHCl3 and (2-furyl)3P to give 2-allyltetrazoles. pi-Allylpalladium azide complex is proposed as a key intermediate in the catalytic cycle and the [3 + 2] cycloaddition between the pi-allylpalladium azide complex and cyano compounds most probably gives the tetrazole frameworks. The deallylation of the derived allyltetrazoles was attained via the two-step procedure; the ruthenium-catalyzed isomerization and ozonolysis. 相似文献
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Namık Özdemir Serkan Dayan Muharrem Dinçer Nilgün Ö. Kalaycıoğlu 《Molecular physics》2013,111(6):707-723
The Schiff base compound (E)-N-{2-[(2-hydroxybenzylidene)amino]phenyl}benzenesulfonamide has been synthesized and characterized by IR, NMR and Uv-vis spectroscopies, and single-crystal X-ray diffraction technique. In addition, quantum chemical calculations employing density functional theory (DFT) method with the 6–311++G(d,p) basis set were performed to study the molecular, spectroscopic and some electronic structure properties of the title compound, and the results were compared with the experimental findings. There exists a good correlation between experimental and theoretical data. Enol-imine/keto-amine tautomerization mechanism was investigated in the gas phase and in solution phase using the polarizable continuum model (PCM) approximation. The energetic and thermodynamic parameters of the enol-imine?→?keto-amine transfer process show that the single proton exchange is thermodynamically unfavored both in the gas phase and in solution phase. However, the reverse reaction seems to be feasible with a low barrier height and is supported by negative values in enthalpy and free energy changes both in the gas phase and in solution phase. The solvent effect is found to be sizable with increasing polarity of the solvents for the reverse reaction. The predicted nonlinear optical properties of the compound are found to be much greater than those of urea. 相似文献
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PdCl_2/SiO_2和Pd-B/SiO_2非晶态合金催化剂的Raman光谱表征 总被引:1,自引:0,他引:1
采用共焦显微Raman光谱和X-射线衍射方法表征了负载型PdCl2/SiO2和Pd-B/SiO2非晶态合金催化剂的结构。结果表明PdCl2分散在SiO2载体上后,与载体表面的相互作用使其在室温时即发生β→α构型转变。Pd-B/SiO2非晶态合金的Raman光谱在300-500cm-1区域内呈现一大的弥散峰。与无负载Pd-B非晶态合金比较初步认定该弥散峰与Pd-B键振动有关,温度升高Pd-B/SiO2催化活性下降,其主要原因为Pd-B/SiO2非晶态合金在高温下逐渐晶化为Pd金属所致。PdCl2与SiO2载体表面的相互作用使其具有较高的分散性,由此还原制备的Pd-B/SiO2非晶态合金较之无负载Pd-B非晶态合金更加微细化,因而具有更大的活性比表面 相似文献
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Moamen S. Refat Mohamed M. Ibrahim Mohamed A. A. Moussa 《Journal of Applied Spectroscopy》2012,78(6):772-781
Charge-transfer complexes (CTC) resulting from interactions of 1,3-di[(E)-1-(2-hydroxyphenyl) methylideneamino]-2-propanol Schiff base with some acceptors such as iodine (I2), bromine (Br2), and picric acid (PiA) have been isolated in the solid state in a chloroform solvent at room temperature.
Based on elemental analysis, UV-Vis, infrared, and 1H NMR spectra, and thermogravimetric analysis (TG/DTG) of the solid CTC, [(Schiff)(I2)] (1), [(Schiff)(Br2)] complexes with a ratio of 1:1 and [(Schiff)(PiA)3] complexes with 1:3 have been prepared. In the picric acid complex, infrared and 1H NMR spectroscopic data indicate that the charge-transfer interaction is associated with a hydrogen bonding, whereas the
iodine and bromine complexes were interpreted in terms of the formation of dative ion pairs [Schiff+, I2∙−] and [Schiff+, Br2∙−], respectively. Kinetic parameters were obtained for each stage of thermal degradation of the CT complexes using Coats–Redfern
and Horowitz–Metzger methods. DC electrical properties as a function of temperature of these charge transfer complexes have
been studied. 相似文献