新铌酸盐Ba3Ni0.33Nb4.67O15的合成与X射线衍射分析

在BaO-Ni2O3-Nb2O5三元系统中,用固相反应法合成了新铌酸盐Ba3Ni0.33Nb4.67O15。以BaCl2和B2O3为主要助熔剂制备了Ba3Ni0.33Nb4.67O15的单晶体。利用四圆单晶衍射仪测定晶胞参数,然后采用X射线粉晶衍射法进行了物相分析,对该化合物的粉晶衍射数据进行了指标化,并报道了其X射线衍射数据。分析结果表明,该化合物属于填满型四方钨青铜结构,空间群P4bm(100),晶胞参数为a=1.26092(5)nm,c=0.40096(4)nm,α=β=γ=90°,Z=2。     

铌酸盐Ba6FeNb9O30的XRD研究

在BaO -Fe2O3-Nb2O5 三元系统中 ,新发现存在铌酸盐Ba6FeNb9O30,利用四圆单晶衍射仪进行了晶胞参数测定 ,然后采用X射线粉晶衍射法获得该化合物的粉晶衍射数据 ,并进行了指标化 ,F30 =32(0.016,58)。XRD分析结果表明 ,该化合物属于填满型四方钨青铜结构 ,晶胞参数为 :a=1.25812(4)nm ,c=0.3992(4)nm ,α=β=γ=90°。     

铌酸盐 Ba5YTi3 Nb7 O30的结构与介电性能

在BaO-TiO2-Mb2O5体系中通过掺Y3－合成了铌酸盐Ba5YTi3Nb7O30 ,采用粉晶X射线衍射（XRD）对其结构进行了分析,并测试了其烧结体的介电特性,结果表明,在室温下Ba4YT3 Nb7O30属于填满型四方钨青铜结构,晶胞参数,a=1.24332(2)nm,c=0.39453(1)nm,α=β=γ＝90度,Ba5TYi3Nb7O30在100度从铁电相转变为顺电相。     

新钽酸盐Ba2LnTi2Ta3O15(Ln=Y、La)的结构与介电性能

通过固相反应法合成了四方钨青铜结构新钽酸盐Ba2LaTi2Ta3O15与Ba2YTi2Ta3O15,分别进行了X射线衍射分析与介电性能测试.结果表明, Ba2LaTi2Ta3O15室温时晶胞参数为a=1.242 64(5) nm, c=0.391 57(2) nm,为四方钨青铜结构顺电相；Ba2YTi2Ta3O15室温时晶胞参数为a=1.236 46(4) nm, c=0.388 60(2) nm,为四方钨青铜结构铁电相,铁电相与顺电相转变温度为180 ℃.频率为1 MHz时, Ba2LaTi2Ta3O15陶瓷的室温相对介电常数为194,介电损耗也降低至8×10－4. Ba2YTi2Ta3O15陶瓷的室温相对介电常数为107.     

新钽酸盐K_6FeTa_(15)O_(42)的合成与表征

在K2O -Fe2O3-Ta2O5 三元系统中 ,新发现存在钽酸盐K6FeTa15O42,使用X射线衍射(XRD)、电子探针微区分析(EPMA)、扫描电镜(SEM)、差热分析(DTA)等方法对该化合物的晶体结构、成分、形态、光学性质、溶解性、熔点及密度进行了研究。新化合物K6FeTa15O42 晶体属于六方晶系,空间群P63/mcm,晶胞参数a=0.91221(1)nm,c=1.21084(4)nm,Z=1,V=0.87258nm3。     

钽酸盐Ba5YTi3Ta7O30的X射线衍射分析及其介电特性

在BaO -TiO2-Ta2O5 体系中通过掺Y3 +合成了钽酸盐Ba5YTi3Ta7O30,采用粉晶X射线衍射 (XRD)对其结构进行了分析 ,并测试了其陶瓷体的介电特性;结果表明 ,Ba5YTi3Ta7O30 在室温下属于填满型四方钨青铜结构顺电相,晶胞参数为a=1.24387(2)nm,c=0.39178(1)nm ,α= β=γ=90° ;频率为1MHz时Ba5YTi3Ta7O30 陶瓷的室温相对介电常数为155 ;而且介电损耗低至0.0009。     

吡啶-2-甲酸镍的合成及其晶体结构

以吡啶 2 甲酸和Ni(ClO4)2·6H2O为原料反应制得配合物[Ni(C5H4NCOO)2(H2O)2]2H2O,并通过X 射线衍射法测定其晶体结构.该化合物属于单斜晶系,空间群P21/n,晶胞参数:a=0.97351(15)nm,b=0.52254(8)nm,c=1.4483(2)nm,β=90.119(3)°,V=0.7367(2)nm3,Z=2,Dc=1.690g/cm3,μ=1.362mm 1,F(000)=388,结构偏离因子R1=0.0316,wR2=0.0902,共收集到4771个强度数据,其中1700个独立衍射点,1489个(I>2σ(I))可观测点.X 射线分析表明晶体是由分子间氢键和π π弱相互作用堆积而成的二维层状结构.     

LnBaB_9O_(16)∶Eu~(3+)(Ln=La,Y)的结构与荧光性质

利用电子衍射、X射线衍射和荧光光谱等方法研究了 L n Ba B9O16(L n=L a,Y)的结构特性 .L n Ba B9O16为单斜晶系 ,其中 L a Ba B9O16的晶胞参数 a=1.36 6 0 nm,b=0 .7882 nm,c=1.6 2 53nm,β=10 6 .15°;YBa B9O16的晶胞参数 a=1.3476 nm,b=0 .7776 nm,c=1.6 0 4 0 nm,β=10 6 .38°.荧光光谱研究表明 ,这两种化合物结构不同 ,Y3 +在 YBa B9O16结构中处于中心对称格位 ,而 L a Ba B9O16中 L a3 +的格位则无中心对称性 .Gd3 +部分取代 L a Ba B9O16∶ Eu3 +中的 L a3 +可改善 Eu3 +离子的发光性质 .L a Ba B9O16∶ Eu3 +在真空紫外区的吸收比较弱 ,这可能与硼氧比较小有关 .     

钼钒氧簇二聚体[Ni(enMe)_2]_4{[Ni(enMe)_2][Ni(enMe)_2(H_2O)]_2[Mo_8~(Ⅵ)V_6~(Ⅳ)O_(38)(V~ⅤO_4)]_2}·8H_2O的合成与结构表征(英文)

在水热条件下合成了一例新型的多金属氧酸盐二聚物,[Ni(enMe)2]4{[Ni(enMe)2][Ni(enMe)2(H2O)]2[Mo8ⅥV6ⅣO38(VⅤO4)]2}.8H2O(1)(enMe=1,2-丙二胺),利用元素分析、红外光谱分析、粉末X射线衍射、热重分析和单晶X射线衍射表征了其结构。结果表明,化合物(1)属于单斜晶系,P2(1)/n空间群.晶胞参数为a=1.9685(4)nm,b=1.3549(3)nm,c=2.7039(5)nm,α=90°,β=93.94(3)°,γ=90°,V=7.195(2)nm3,Z=4,Dc=2.390g/cm3,Mr=2588.4,μ=3.195mm-1,F(000)=5012,最终R1=0.0743,wR2=0.1861.与此同时,(1)是第一个具有二帽-Keggin型钼钒氧簇的二聚体,它由过渡金属部分[Ni(enMe)2(H2O)]22+连接形成{[Ni(enMe)2][Ni(enMe)2(H2O)]2[Mo8ⅥV6ⅣO38(VⅤO4)]2}8-二聚阴离子.     

钴(Ⅲ)-胺配合物模板导向合成新型草酸盐化合物[Co(dien)2][NaCO2(C2O4)4]·H20

以Co(dien)2·Cl3为模板剂,在水热条件下导向合成出新型草酸盐化合物[Co(dien)2]·[NaC02(C2O4).].H2O,并通过X射线单晶结构分析、元素分析、ICP以及X射线粉末衍射分析对该化合物的结构进行了表征.结果表明,该化合物结构属于单斜晶系,C2/c空间群,晶胞参数a=1.3805(3)nm,b...     

OH(3) (-) and O(2)H(5) (-) double Rydberg anions: predictions and comparisons with NH(4) (-) and N(2)H(7) (-)

A low barrier in the reaction pathway between the double Rydberg isomer of OH(3) (-) and a hydride-water complex indicates that the former species is more difficult to isolate and characterize through anion photoelectron spectroscopy than the well known double Rydberg anion (DRA), tetrahedral NH(4) (-). Electron propagator calculations of vertical electron detachment energies (VEDEs) and isosurface plots of the electron localization function disclose that the transition state's electronic structure more closely resembles that of the DRA than that of the hydride-water complex. Possible stabilization of the OH(3) (-) DRA through hydrogen bonding or ion-dipole interactions is examined through calculations on O(2)H(5) (-) species. Three O(2)H(5) (-) minima with H(-)(H(2)O)(2), hydrogen-bridged, and DRA-molecule structures resemble previously discovered N(2)H(7) (-) species and have well separated VEDEs that may be observable in anion photoelectron spectra.     

Mixed ligand titanium(IV) complexes. Chlorobis(dithiocarbamato)bis(methylsalicylato)titanium(IV) andbis(dithiocarbamato)bis(methylsalicylato)titanium(IV)

Summary Dichlorobis(methylsalicylato)titanium(IV) reacts with potassium or amine salts of dialkyl or diaryl dithiocarbamates in 11 and 12 molar ratios in anhydrous benzene (room temperature) or in boiling CH₂Cl₂ to yield mixed ligand complexes: (AcOC₆H₄O)₂ Ti(S₂CNR₂)Cl (1) and (AcOC₆H₄O)₂ Ti(S₂CNR₂)₂ (2), R=Et, n-Pr, n-Bu, cyclo-C₄H₈ and cyclo-C₅H₁₀. These compounds are moisture sensitive and highly soluble in polar solvents. Molecular weight measurement in conjunction with i.r.,¹H and¹³C n.m.r. spectral studies suggest coordination number 7 and 8 around titanium(IV) in (1) and (2) respectively.     

Bis(trifluoroacetyl) peroxide, CF(3)C(O)OOC(O)CF(3)

Pure, highly explosive CF(3)C(O)OOC(O)CF(3) is prepared for the first time by low-temperature reaction between CF(3)C(O)Cl and Na(2)O(2). At room temperature CF(3)C(O)OOC(O)CF(3) is stable for days in the liquid or gaseous state. The melting point is -37.5 degrees C, and the boiling point is extrapolated to 44 degrees C from the vapor pressure curve log p = -1875/T + 8.92 (p/mbar, T/K). Above room temperature the first-order unimolecular decay into C(2)F(6) + CO(2) occurs with an activation energy of 129 kJ mol(-1). CF(3)C(O)OOC(O)CF(3) is a clean source for CF(3) radicals as demonstrated by matrix-isolation experiments. The pure compound is characterized by NMR, vibrational, and UV spectroscopy. The geometric structure is determined by gas electron diffraction and quantum chemical calculations (HF, B3PW91, B3LYP, and MP2 with 6-31G basis sets). The molecule possesses syn-syn conformation (both C=O bonds synperiplanar to the O-O bond) with O-O = 1.426(10) A and dihedral angle phi(C-O-O-C) = 86.5(32) degrees. The density functional calculations reproduce the experimental structure very well.