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1.
结果表明,LixNi0.3Co0.7O2具有六方晶系R3-m空间群结构。当X=1,0.315时,其晶胞参数分别为a=2.826nm,c=14.130nm和a=0.2808nm,c=1.4253nm;MO6(M=Ni,Co)八面体中M-O平均距离分别为0.1941nm和0.1933nm。XPS分析结果表明LIxNi0.3CO0.7O2表面存在Li2O,同时探讨了其中过渡金属离子的3d电子结构变化。  相似文献   

2.
结果表明,LixNi0.3Co0.7O2具有六方晶系R3^-m空间群结构。当X-1,0.315时,其晶胞参数分别为a=2.826nm,c=14.130nm和a=0.2808nm,c=1.4253nm;MO6(M=Ni,Co)八面体中M-O平均距离分别为0。1941nm和0.1933nm。XPS分析结果表明LIxNi0.3CO0.7O2表面存在Li2O,同时探讨了其中过渡金属离子的3d电子结构变化。  相似文献   

3.
合成子Ni替代铁酸稀土复合氧化物LaF31-xNixO3(x=0.1-0.6),对样品进行了XRD、IR及Mossbauer谱测试,结果表明:x=0\1,0\2,0\3的样品为正交相,x=0.5,0.6的样品为菱方相;伴随相结构从正交向菱方结构的转变,IR谱上Fe(Ni)-O键伸振动谱带向高频移动近20cm^-1,Mossbauer谱测试表明Fe均处于+3自旋态,Ni离子以+3价进入晶格。  相似文献   

4.
CpM(CO)3SnPh3和CpM(co)3sNpH2x(Cp=C5H4CH3,C5H4COCH3;M=Mo,W;X=Cl,Br)与HCl或HBr发生取代反应,得到三氯、三溴以及混合三卤代锡钨(钼)双核化合物,并经元素分析、^1H NMR、IR表征。化合物Cl3SnW(CO)3C5H4COCH3的晶体属单斜晶系,空间群为P21/c,a=0.7686(3)nm,b=1.2622(2)nm,c=1.6  相似文献   

5.
合成了一系列结构为层磁状ABO3的复合氧化物La4BaCu5-xMxO13(M=Mn,Co),并利用XRD、X射线能谱、氧程序升温脱附和化学分析方法对它们的结构和活性氧种进行了研究。XRD分析结果表明:它们的结构为五层的ABO3结构。玫瑰中a4BaCu5O13中掺Mn或Co之后,样品中明显存在的M-Cu(M=Mn,Co)之间的协同作用,并且Co-Mn之间协同作用明显比Cu-Co的强。  相似文献   

6.
采用水热合成及离子交换方法将缺位及单取代型Keggin结构钨硅杂多含氧酸根SiW(11)及SiW(11)O(39)Z(H2O)(6-)嵌入Zn─Al型阴离子粘土层间,得到了大层间距的新型层往状微孔材料ZnAl─SiW(11)及ZnAl—SiW(11)Z(Z=Co(2+)、Ni(2十)和Cu(2+)),XRD与IR测试结果表明,它们只有9.7 的通道高度.  相似文献   

7.
以层状α-磷酸锆为插层主体,采用高温固相离子交换插层法制备Cu^2+,K柱撑的磷酸锆类层柱催化剂,并用XRD,IR和TG等方法对其进行了表征。结果表明,金属离子柱撑的α-磷酸锆类层柱催化剂的层间距由原来的0.76nm扩撑至0.81nm,结晶度有所下降。  相似文献   

8.
纳米尖晶石型Co2MnO4的形成过程及其F-T反应性能   总被引:2,自引:0,他引:2  
梁琦 《催化学报》1998,19(1):33-36
用溶胶凝胶法制备了尖晶石型Co2MnO4超细粒子,用DTATG,XRD,TEM,FTIR等手段研究了Co2MnO4超细粒子的形成过程,进而用反应评价结合XRD,XPS,BET比表面积测试研究了Co2MnO4催化剂的比表面积和表面结构与其FT反应性能间的关系.结果表明,Co2MnO4超细粒子可以在较低温度(250~350℃)下形成,并具有粒度小,分布均匀等特点.用该法制备的超细粒子Co2MnO4,其催化活性明显优于相同组成的大颗粒催化剂.  相似文献   

9.
在不同条件下合成了[Co(phen)mXp]Y1·nH2O型配合物,(m=1,2;p=1,2;1=1-3;n=0-4;phen=邻菲绕啉;X=Cl-,H2O,酒石酸(tart),甘氨酸(gly),α-皮可林酸(pic).DL-两氨酸(ala),L-亮氨酸(leu),L-脯氨酸(pro);Y=Cl-,]并进行了元素分析,热重分析,电子光谱,红外光谱和磁化率测定,计算它们的10Dq和B值.X-ray单晶衍射实验证明:[Co(Phen)2(H2O)2](NO3)3·2H2O,[Co(Phen)2(gly)]Cl2·4H2O均为顺式结构.[Co(Phen)(ala)2]Cl·3H2O,[Co(Phen)(pro)2]ClO4·4/3H2O均为trans(N)结构.在[Co(phen)2X2](n+)型配合物中,X反位的键长均长于顺位键长,其反位效应的顺序为:Cl->羧基,NH2>H2O。  相似文献   

10.
合成了一系列结构为层状ABO3的复合氧化物La4BaCu5-xMxO13(M=Mn,Co),并利用XRD、X射线能谱、氧程序升温脱附和化学分析方法对它们的结构和活性氧种进行了研究。XRD分析结果表明:它们的结构为五层的ABO3结构。活性氧种的研究表明La4BaCu5O13中掺杂Mn或Co之后,样品中明显存在的MCu(M=Mn,Co)之间的协同作用,并且CuMn之间协同作用明显比CuCo的强。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

13.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

14.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

15.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

16.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

17.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

18.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

19.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

20.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

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