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1.
《光谱实验室》2002,19(2):153-156
本文通过对[Fe 3O(Ala) 6(H 2O) 3](ClO 4) 7和[Fe 3O(Gly) 6(H 2O) 3](NO 3) 7·3H 2O的ESR谱的解析及变温磁化率的研究,得出它们的ESR谱具有各向同性的特点;朗德因子分别为2.019和1.997;两种配合物中铁离子间有反铁磁相互作用.  相似文献   

2.
Based on the universal properties of a critical point in different systems and that the QCD phase transitions fall into the same universality classes as the 3-dimensional Ising, O(2) or O(4) spin models, the critical behavior of cumulants and higher cumulant ratios of the order parameter from the three kinds of spin models is studied. We found that all higher cumulant ratios change dramatically the sign near the critical temperature. The qualitative critical behavior of the same order cumulant ratio is consistent in these three models.  相似文献   

3.
Ab initio within the full potential linearized augmented plane wave (FP-LAPW) method with the GGA+U approach is applied to study the electronic structures of two compounds NaK3(NpO2)4(SO4)4(H2O)2 and NaNpO2SO4H2O. The present calculations show that the major part of the spin magnetic moment in these two compounds is from Np(V) ions, and the origin of the cation-cation interactions between Np comes from the spin polarization effect within Np-ONv-Np bonds.  相似文献   

4.
三核铁甲酸簇合物[Fe3(μ3—O)(μ—O2CH)6(H2O)2...   总被引:2,自引:0,他引:2  
  相似文献   

5.
本文对二种具有新奇结构的[NaXY]2WnMo6-nO19(Ⅰ.X=DB18C6,Y=CH3OH,n=4;Ⅱ.X=DB24C8,n=1)冠醚钼钨杂多酸超分子配合物进行了核磁共振和红外光谱测定,判定了谱图的归属并考察了结构与谱学参数之间的关系。  相似文献   

6.
7.
The quantum tunnelling of magnetization (QTM) in single crystals of the single molecule magnet (Mn1-xCrx)12- Ac (x=0, 0.03, 0.04, 0.05) has been investigated. In comparison with its parent Mnl2-Ac, a greater rate of magnetization relaxation and a lower effective potential-energy barrier have been observed in Cr-doping samples. This modulation of QTM due to the Cr-doping could be attributed to the small change of Sz due to the smaller spin of Cr itself and additional intrinsic but distributed transverse and longitudinal anisotropy raised by a subtle change of the local environment in the magnetic Mn12 core.  相似文献   

8.
本文采用水热反应条件 ,合成得到一种新型的含五价钼原子的杂多化合物 :(NH3CH2 CH2 NH3) 7H2[NaMo1 2 O30 (PO4 ) 2 (HPO4 ) 5(H2 PO4 ) ]·7H2 O ,在晶体结构测定的基础上对其进行红外、拉曼和紫外 可见漫反射光谱研究。结果表明 :较长的Mo(Ⅴ )—O键键长和分子内大量的氢键造成化合物红外光谱特征的红移。  相似文献   

9.
徐涵 《光谱实验室》2013,(6):2800-2805
用溶液法合成了标题化合物[Cu2(NPG)4(4,4'-bipy)2(H2O)2]·2H2O(HNPG=邻苯二甲酰甘氨酸4,4'-bipy=4,4'-联吡啶),并通过X射线衍射对其单晶结构进行了测定.该结构属于三斜晶系,空间群P1,分子量Mr=1328.14,晶胞参数a=0.85512 (15)nm,b=1.7083 (3)nm,c=2.1115(4)nm,V=2.9996(9)nm3,Z=2,Dc=1.470g·cm-3,F(000)=1364.0.Cu(Ⅱ)配位形成变形的三角双锥构型,配合物的分子间和分子内氢键及π-π堆积将其拓展为三维结构,并对稳定晶体结构起着重要的作用.  相似文献   

10.
利用原位红外光谱法研究标题化合作在N2 中的反应行为。发现它们在不同温度下能使丙酸分别转化为乙醛和戊酮。金属氧化物对丙酸的戊酮化反应活性顺序是 :Fe3O4 >MnO2 >Cr2 O3>Co2 O3>Ni2 O3,这顺序与下列簇合物对该反应的活性顺序类似 :[Fe2 MnOPH]>[Fe3OPH]>[Fe2 CrOPH]>[Fe2 CoOPH]>[Fe2 NiOPH]>[Cr3OPH][OPH =(μ3 O) (μ O2 CC2 H5) 6(H2 O) 3]。对于戊酮化反应 ,过渡金属氧化物的反应温度明显高于相应的 [Fe2 MOPH]的反应温度 ,这旁证了 [Fe2 MOPH]的活性组分不是其金属氧化物。还讨论了Fe3O4 ,Fe2 O3 对丙酸分别转化为乙醛和戊酮反应活性的明显差异。  相似文献   

11.
采用溶剂挥发扩散法合成了配合物单晶[Zn(DMF)2(H2O)4]·C8Cl4O4,其中DMF为N,N′-二甲基甲酰胺。配合物为三斜晶系,P-1空间群,其晶胞参数为n=0.57680(10)nm.6=0.85991(14)nm,c=1.2030(2)nm,α=95.781(3)°,β=102.074(3)°,γ:98.594(2)°,V=0.57154nm^3,Z=1,Mr=585.51,Dc=1.701g/cm^3,F(000)=298,μ=1.594mm^-1,最终偏差因子R1=0.0315,ωR2=0.0914.和R1=0.0345,ωR2=0.0946,同时采用红外光谱分析、元素分析对其进行表征。  相似文献   

12.
Using the first-principles plane-wave pseudopotential method, based on the density function theory, the electron structure and optical properties of GaAs (100) β2(2×4) and GaAs (100) (4×2) reconstructions are calculated. The formation energy of As-richβ2 (2 ×4) reconstruction is minus and the formation energy of Ga-rich (4×2) reconstruction is positive; As-rich β2(2×4) reconstruction is stable and Ga-rich (4×2) reconstruction is unstable. Ga-rich (4×2) reconstruction owns lower work function. The electrons at two reconstructions both move into the bulk and form a band-binding region. Both the absorption and the refleetivity of As-rich β2(2×4) reconstruction are smaller than the Ga-rich (4× 2) reconstruction. As- rich β2(2×4) reconstruction is more benefit for the movement of photos through the surface to emit photoelectrons.  相似文献   

13.
本文通过X射线衍射、差热分析和超导电性测量等手段对Bi1.6Pb0.4Sr2Ca2-x(Nd0.75Ce0.25)xCu3Oy体系的相结构和超导电性进行了研究.该体系中,在810—840℃空气中烧结40小时样品的Te随着x增加而降低.研究了在750-820℃烧结样品的超导电性与组成的关系.x=1.6—2.0,在750—820℃空气中烧结40小时样品的超导转变温度为19—21K.这种超导电性可能是由于部分被稳定的Bi-2222相所致.  相似文献   

14.
用FTIR, NIR FT-Raman, UV-Vis DRS和荧光光谱等对五个新型具有[(PO4)4MoⅤ6O15]12-阴离子簇的化合物: Na·(H4TETA)3·(H3O)5·{Zn[(HPO4)2(PO4)2Mo6O15]2} (2), (H2 en)7·(H3O)4·{Cu[(HPO4)2(PO4)2Mo6O15]2}·H2O (3), (H3DETA)2·(H3O)3·{Co0.5[(HPO4)2(PO4)2Mo6O15]}·H2O (4), [Co(H3TETA)]2{Co0.5[(HPO4)(PO4)3Mo6O15]}·3.5H2O (5)和(H3DETA)·(H3O)4·{Co1.5[(HPO4)2(PO4)2Mo6O15]}·0.5H2O (6), 进行研究, 并探讨其结构和性能的关系. 这些化合物具有{M[(PO4)4Mo6 O15]2}二聚体单元, 化合物2~4的二聚体间通过与有机分子和水分子的氢键形成三维网状结构; 化合物5和6的{Co[(PO4)4Mo6O15]2}二聚体间是分别通过 [CoH3TEATA]基团和CoO4四面体组成网状结构. 磷钼酸盐的特征振动频率和这些化合物的结构相关; 化合物的三个UV-Vis DRS特征谱带分别属于Od→Mo, Oμ→Mo 和O→M电荷转移; 观察到以240 nm激发, 在410 nm附近出现的由Oμ→Mo跃迁激发引起的较强的荧光发射谱带.  相似文献   

15.
本文通过稀土高氯酸盐与L-丙氨酸(L-Ala)及咪唑(Im)反应,合成了标题配合物RE(Ala)4(Im)(ClO4)3*2H2O(RE=Pr,Nd,Sm),测定了配合物的红外光谱,对其主要吸收带进行了归属.红外光谱的研究结果表明,丙氨酸以内盐的形式存在于配合物中,通过羧基与稀土离子配位,且随着RE原子量的增大,羧基与RE3+间配位键离子性逐渐减弱,共价性逐渐增大;咪唑环上的N参与了配位.  相似文献   

16.
Five novel organic-molybdenum phosphates with [(PO4)4Mo6(V)O15]12- cluster, Na x (H4TETA)3 x (H3O)5 x {Zn[(HPO4)2(PO4)2Mo6O15]2} (2), (H2en)7 x (H3O)4 x {Cu[(HPO4)2(PO4)2Mo6O15]2} x H2O (3), (H3DETA)2 x (H3O)3 x {Co0.5[(HPO4)2(PO4)2Mo6O15]} x H2O (4), [Co(H3TETA)]2{Co0.5[(HPO4)(PO4)3Mo6O15] x 3.5H2O (5) and (H3DETA) x (H3O)4 x {Co1.5 [(HPO4)2(PO4)2Mo6O15]} x 0.5H2O (6), have been synthesized. The relationship between their properties and structures was studied by using FTIR, NIR FT-Raman, UV-Vis DRS and fluorescence etc. In these compounds, every two [(PO4)4Mo6O15] clusters are coordinated by a metal atom to form a {M[(PO4)4Mo6O15]2} dimer. In compound 2, 3 and 4, {M[(PO4)4Mo6O15]2} dimers are hydrogen-bonded by the organic molecules and water molecules to form a three-dimensional expended framework, respectively. In compound 5 and 6, {Co[(PO4)4Mo6O15]2} dimers are coordinated by [Co(H3TETA)] groups and [CoO4] tetrahedra to form a network, respectively. These characteristic vibrational frequencies of the molybdenum phosphates are related to the structure of these compounds. Three characteristic bands in UV-Vis DRS spectra of these compounds have to be attributed to the absorptions of O(d) --> Mo, O(mu) --> Mo and O --> M charge transfer, respectively. These compounds exhibit strong fluorescence emission bands at about 410 nm when excited by 240 nm, which are caused by O(mu) --> Mo charge transfer.  相似文献   

17.
研究了压力和温度对单斜辉石的结晶和晶粒纤维编织的影响。在较低的晶化温度下压力对单斜辉石结晶的影响很明显,这种影响随温度升高而减弱。然而,压力对单斜辉石晶粒纤维编织的影响正相反,在相同的高温下,较高压力下晶化的单斜辉石晶粒纤维比较低压力下得到的晶粒纤维粗壮,而且编织紧密。  相似文献   

18.
The quantum tunnelling of magnetization (QTM) in single crystals of the single molecule magnet (Mn1-xCrx)12- Ac (x=0, 0.03, 0.04, 0.05) has been investigated. In comparison with its parent Mnl2-Ac, a greater rate of magnetization relaxation and a lower effective potential-energy barrier have been observed in Cr-doping samples. This modulation of QTM due to the Cr-doping could be attributed to the small change of Sz due to the smaller spin of Cr itself and additional intrinsic but distributed transverse and longitudinal anisotropy raised by a subtle change of the local environment in the magnetic Mn12 core.  相似文献   

19.
研究了结晶紫-H2O体系浮选分离A u(SCN)4-的行为及与一些金属离子分离的条件。结果表明,在水溶液中,Au(Ⅲ)与结晶紫(CV)和硫氰酸铵形成不溶于水的三元缔合物A u(SCN)4-.CV+,此三元缔合物沉淀浮于水相上层形成界面清晰的液-固两相。当溶液中结晶紫和硫氰酸铵的浓度分别为7.0×1-0 4m ol/L和5.0×1-0 3mol/L时,Au(Ⅲ)可与R h(Ⅲ)、G a(Ⅲ)、Mn(Ⅱ)、A l(Ⅲ)、Ni(Ⅱ)、Cd(Ⅱ)、F e(Ⅱ)、Mg(Ⅱ)和Sn(Ⅳ)离子分离。该方法具有简便、快速和不污染环境等特点,在微量金的分离和富集分析中有一定的实用价值。  相似文献   

20.
在晶体场理论基础上,该文得到3d9离子在伸长四角畸变晶场中的电子能级和三阶微扰的g因子公式。作为公式的应用,文中研究了晶体Cu6Si6O186H2O内Cu2+离子的电子吸收光谱和EPRg因子,理论计算与实验结果进行了比较  相似文献   

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