首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
在水热的条件下合成了1个标题的Mo-Ni-O异核簇合物,化学式为H34Ni5Mo12O52 (Mr = 2311.10),用单晶X射线衍射方法测定了它的结构,该晶体属四方晶系,I41/amd空间群,晶胞参数为a = 15.319(2),c = 30.645(3) ,V = 7191.2(16) 3,Z = 4,Dc = 2.135 g/cm3,μ= 3.369 mm-1, F(000) = 4376, 1036个可观察衍射点(I > 2s(I)),最终结构偏离因子R = 0.0560,wR = 0.1632,S = 1.002。该化合物簇阴离子笼中心是Ni2+,由12个MoO6八面体和4个NiO6八面体通过共角和共边构成。  相似文献   

2.
(enH2)5[(VO)12O6B18O36(OH)6]·2(H3O)·6H2O的水热合成和晶体结构   总被引:1,自引:0,他引:1  
以NH4VO3,H3BO3,乙二胺,MoO3,H2O为原料,按物质的量比2∶20∶9∶3∶222,在180℃条件下晶化,得到黑色棱形晶体(enH2)5[(VO)12O6B18O36(OH)6].2(H3O).6H2O.单晶结构分析结果表明该化合物属三斜晶系,Pī空间群,晶胞参数a=1.336 8(3)nm,b=1.599 8(3)nm,c=1.663 4(3)nm,α=94.040(1)°,β=91.530(1)°,γ=95.830(1)°,V=3.528 1(12)nm3,Z=2,Dc=2.099 g/cm3,μ=1.649 mm-1,F(000)=2 228,15 641个可观察独立衍射点射点(I>2σ(I)),最后结构精修到偏离因子R1=0.047 5,wR2=0.150 4,S=1.039.该化合物的结构主要由阴离子簇[(VO)12O6B18O36(OH)6]12-构成.该阴离子簇由B18O36(OH)6十八元环夹在两个以共边交替相连形成的V6O18簇中间,通过共用氧原子形成三明治式结构新颖的硼-钒-氧离子簇,簇间填充了一些(enH2)2+离子和水分子.  相似文献   

3.
利用三苄基氧化锡与2-吡咯甲酸反应,合成六聚体-苄基锡氧2-吡咯甲酸酯簇 合物.通过元素分析、红外光谱、核磁共振氢谱和X射线单晶衍射对其结构进行了 表征.X射线单晶衍射测试结果表明:化合物为三斜晶系,空间群P1^-,α=1. 2644(3)nm,b=1.7416(4)nm,c=1.9285(4)nm,α=90.021(4)°,β=94. 585(4)°,γ=90.021(4)°,Z=2,V=4.2330(16)nm^3,Dc=1.715g/cm^3 ,μ=1.936mm^-1,F(000)=2136,R=0.0527,wR=0.0708.该化合物为鼓型 簇状结构,锡原子为畸变的八面体构型.  相似文献   

4.
利用水热合成法合成了分子组成为(C6H11NH3)5H(P2Mo5O23)4H2O的杂多化合物, 用单晶X-ray衍射方法测定了它的结构,该晶体属于单斜晶系,空间群P21/c, a = 12.830(3), b = 14.848(3), c = 25.258(5) ? b = 92.95(3), Mr = 1483.62, V = 4805.1(17) 3, Z = 4, Dc = 2.051 g/cm3, m = 1.431 mm-1, F(000) = 3000, I >2s(I) 的可观察衍射点4426个, 最终结构偏差因子R = 0.0464, wR = 0.0801, S = 0.731。在[P2Mo5O23]6-杂多阴离子中5个MoO6八面体通过共边和共角相连, 形成1个近似的五角平面骨架, 2个PO4四面体加在五角平面的两侧。热性质研究表明杂多阴离子骨架在547.4 ℃左右分解。  相似文献   

5.
新化合物PbCuP2O7的单晶通过高温固相反应制备得到,使用X一射线四园衍射仪测定了它的单晶结构.PbCuP2O7属单斜晶系,空间群为P21/n,晶胞参数:α=5.381(1),b=8.2O5(2),C=12.57O(3)A,β=90.49(3)°,Z=4.使用1311个I>2σ(I)反射修正101个变量参数,最终收敛到R=0.O54.其晶体结构是由共顶点的CuO5四方锥和P2O7集团沿α轴形成较大的孔道所组成,Pb原子位于由两个四方锥和三个PO4四面体的棱所夹的五角形孔道中.  相似文献   

6.
在水热的条件下合成了1个多聚钒硼酸盐[Ni(en)2]6H2[(VO)12O6B18O42]15H2O,化学式为C24H128B18N24Ni6O75V12(Mr=3111.62),用单晶X射线衍射方法测定了它的结构,该晶体属三方晶系,R-3空间群,晶胞参数为a=13.942(2)?=96.476(2),V=2653.9(5)?,Z=1,Dc=1.947g/cm3,=21.55cm-1,F(000)=1574,2108个可观察衍射点(I>2(I)),最终结构精修到偏离因子R=0.0594,wR=0.1398,S=1.009。在该化合物的结构中,18员环的B18O42通过18个B(3-O)V键被2个V6O15簇夹在中间,6个[Ni(en)2]基团分别通过2个Ni(3-O)B与B18O42环相连。  相似文献   

7.
刘杰 《结构化学》1998,17(3):225-229
采用电解法制备了未见文献报道的杂多蓝H8[SiMo11Co(H2O)O39]·20H2O,通过X-射线衍射测定了其晶体结构,该晶体属单斜晶系,空间群P21;。晶胞参数全矩阵最小二乘法修正至中心原子Si与4个氧形成四面体结构,配原子M(M=11/12Mo+1/12Co)与O形成12个MO6八面体结构3个MO6共边形成4个M3O13三金属簇,4个三金属簇与SiO4四面体共角相连形成阴离子结构。  相似文献   

8.
在水热的条件下合成了多钒硼酸盐(enH2)4Na4H3[(VO)12O6B18O42]8H2O, 化学式为C8H59B18N8Na4O68V12 (Mr=2253.45), 用单晶X射线衍射方法测定了它的结构, 该晶体属单斜晶系, P21/n空间群, 晶胞参数为a = 13.8989(4), b = 16.1954(5), c = 14.4520(4) ?β = 94.7490(5), V= 3241.95(16) ?, Z = 2, Dc = 2.308 g/cm3, ?= 1.819mm-1, F(000) = 2234, 4798个可观察衍射点(I > 2s(I)), 最终结构精修到偏离因子R = 0.0449, wR = 0.1163, S = 0.996。在该化合物的结构中, V12B18簇是由环状的B18O42通过18个B(μ3-O)V键被2个V6O18环夹在中间组成的, V12B18簇通过4个Na+与相邻的簇相连, 形成二维网状结构, 孔道尺寸为6.109×10.562 拧?  相似文献   

9.
采用水热方法合成一种新型钼-氧簇化合物Ni(en)3MoO4,并通过X射线单晶结构分析、红外光谱分析、元素分析、差热热重分析对该化合物进行了表征.结构分析数据表明该化合物属三方晶系,P-31c空间群,晶胞参数a=0.922 6(13) nm,b=0.922 6(13) nm,c=0.995 9(2) cm,α=90°,β=90°,γ=120°,V=0.734 2(2) nm3,Z=2,Dc=1.805 mg/ m3,μ=2.153 mm-1,F(000)=408,R=0.055 3,Rw=0.173 2;该化合物是分立结构,是由MoO4四面体簇和Ni(en)3八面体簇形成,其中MoO4四面体簇和Ni(en)3八面体簇交替排列,存在较强的氢键作用,结构中分立的手性配合物Ni(en)3的两种对映体构象以MoO4簇为中心对称排布.  相似文献   

10.
利用(PhCH_2)_3Sn]_2O与ArCH=CHCO_2H反应,合成6个新的[PhCH_2Sn(O) (O_2CCH=CHAr)]_6簇合物。通过元素分析、红外光谱和X射线单晶衍射对其结构进 行了表征。用X射线单晶衍射测定了[PhCH_2Sn(O)(O_2CCH=CHPh)]_6的晶体结构, 结果表明,该簇合物为三斜晶系,空间群P1, a = 1.6771(3) nm, b = 1.8020(4) nm, c = 2.1073(4) nm, α = 108.111(3)°β = 103.614(3)°,γ = 104.679 (3)°,Z = 2, V = 5.5033(18) nm~3, D_c = 1.350 g/cm~3, μ = 1.396 mm~(-1) , F(000) = 2208, R = 0.0606, wR = 0.698。该化合物为鼓型簇状结构,锡原子 呈畸变的八面体构型。  相似文献   

11.
The reactions of H2O+, H3O+, D2O+, and D3O+ with neutral H2O and D2O were studied by tandem mass spectrometry. The H2O+ and D2O+ ion reactions exhibited multiple channels, including charge transfer, proton transfer (or hydrogen atom abstraction), and isotopic exchange. The H3O+ and D3O+ ion reactions exhibited only isotope exchange. The variation in the abundances of all ions involved in the reactions was measured over a neutral pressure range from 0 to 2 × 10−5 Torr. A reaction scheme was chosen, which consisted of a sequence of charge transfer, proton transfer, and isotopic exchange reactions. Exact solutions to two groups of simultaneous differential equations were determined; one group started with the reaction of ionized water, and the other group started with the reactions of protonated water. A nonlinear least-squares regression technique was used to determine the rate coefficients of the individual reactions in the schemes from the ion abundance data. Branching ratios and relative rate coefficients were also determined in this manner.A delta chi-squared analysis of the results of the model fitted to the experimental data indicated that the kinetic information about the primary isotopic exchange processes is statistically the most significant. The errors in the derived values of the kinetic information of subsequent channels increased rapidly. Data from previously published selected ion flow tube (SIFT) study were analyzed in the same manner. Rigorous statistical analysis showed that the statistical isotope scrambling model was unable to explain either the SIFT or the tandem mass spectrometry data. This study shows that statistical analysis can be utilized to assess the validity of possible models in explaining experimentally observed kinetic behaviors.  相似文献   

12.
13.
14.
15.
Freezing-point depression of mixtures of H 2 16 O and H 2 18 O were measured. The results showed that the freezing point of the mixture rose linearly with an increase in the molal concentration of H 2 18 O. The results suggested the formation of a solid solution of H 2 16 O and H 2 18 O by freezing, similar to that formed by H 2 O–D 2 O, and that H 2 18 O behaves as a different molecule than H 2 16 O.  相似文献   

16.
17.
18.
19.
20.
The proton magnetic shielding constants in the water molecule and its linear perpendicular dimer are computed from SCF-MO-LCGO wave functions by using the uncoupled Hartree-Fock variation-perturbation procedure due to Karplus and Kolker. The convergence of the calculated shielding constants as well as their gauge dependence is studied. The final results for 17-term polynomial variation function indicate that the best choice for the gauge origin corresponds to the molecular electronic centroid.The calculated proton magnetic shielding constant in the water molecule is in remarkable agreement with experimental data and favourably compares with the best coupled Hartree-Fock results. It follows from the calculations for the water dimer that the H-bond NMR-shift amounts in this case —1.0 ppm and qualitatively agrees with the experimental data for the liquid water.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号