基于[LnMo12]二十面体的三维稀土钼酸盐骨架的合成、结构及荧光性能

通过缓慢蒸发溶剂法合成了2例新的三维稀土钼酸盐：[Ln (H₂O)₃]₃[LnMo₁₂O₄₂]·xH₂O,其中Ln=Eu (1)、Tb (2),x=7(1),10.17(2)。这2种稀土钼酸盐中都含有新颖的二十面体[LnMo₁₂O₄₂]构建单元,该单元通过与{LnO₉}多面体进一步连接形成三维网络。光致发光测试表明,化合物1和2显示出明显不同的发射特征,这与Eu³⁺和Tb³⁺离子的不同能级跃迁密切相关。化合物1表现出较强的红色发射(CIE色度坐标为(0.66,0.33))、高发光强度、较大的荧光量子产率(约60%),对应于从⁵D0到⁷F_J (J=4、3、2、1、0)的跃迁;化合物2表现出浅绿色发射(CIE色度坐标为(0.34,0.60)),对应从⁵D₄到⁷F_J (J=6、5、4、3)的能级跃迁,其发光强度较弱和荧光量子产率较低(约20%)。有趣的是,一定量的Tb³⁺引入和大量溶剂分子的存在导致化合物2发生部分荧光猝灭,但对化合物1的荧光几乎没有影响。     

稀土配位聚合物[M(tddc)(NO3)(H2O)4]·2H2O(M=Eu，Dy)的合成、结构和性质

本文用水热法合成了2个稀土配位聚合物[M(tddc)(NO₃)(H₂O)₄]·2H₂O[M=Eu (1),M=Dy (2)],并对它们进行了元素分析、红外光谱、热重等分析,研究了它们的荧光性质,并用X-射线单晶衍射测定了配合物的单晶结构。两者的晶系都属于三斜晶系,P1空间群。荧光实验表明配合物1在常温下具有很强的荧光。     

具有类白钨矿结构的KGd（MoO4）2的晶体结构和能带结构

以Gd₂O₃、K₂CO₃、MoO₃为原料,采用高温熔盐法,合成了一个含钾的稀土钼酸盐KGd（MoO₄）₂。通过X射线单晶衍射法测定了它在室温下的晶体结构,并测定了它的光学性质。结构分析表明它属于三斜晶系,空间群为P1,a=0.52923（6）nm,b=0.69210（6）nm,c=1.06889（7）nm,α=75.79（8）°,β=76.79（5）°,γ=67.60（4）°,Z=2,R₁（alldata）=0.0258。结构中的K和Gd原子位于各自的晶体学位置,不存在调制结构的现象。此外,我们用得到的晶体学数据,通过密度泛函理论研究了化合物的能带结构、态密度、介电常数,其结果和实验数据相吻合。     

聚合物[Zn(pht)(pzH)2]n的合成，晶体结构与荧光性质

A Zn(Ⅱ) coordination polymer [Zn(pht)(pzH)₂]_n (where pht^2-=dianion of o-phthalic acid, pzH=pyrazole) has been synthesized and the structure was determined by X-ray diffraction. The complex crystallizes in the monoclinic space group P2₁/c, a=0.821 39(10) nm, b=1.662 2(2) nm, c=1.156 42(14) nm, β=100.349(2)°, V=1.5532(3) nm³, Z=4. Both carboxylate groups of the phthalate dianion coordinated in a monodentate mode bridged two Zn(Ⅱ) atoms forming the structure of 1-D chain. The pyrazole ligands play two different roles: one only coordinates the metal atom and the other joins the coordination polymer into a 2-D sheet via N-H…O and C-H…O hydrogen bonds besides the coordination property. A blue photoluminescence peak at 435 nm was observed in solid state at room temperature. CCDC: 227946.     

混合价钼锗酸盐的合成、结构及性质研究

合成了单电子还原混合价杂多化合物 [C10H10N]4HGeMo12O40,并由元素分析、 IR、 UV进行了表征。单晶 X射线分析表明 ,属单斜晶系 ,空间群 P21/n,晶胞参数 a=1.4803(3),b=1.2582(3),c=1.7712(4)nm,β =98.31(3)° ,V=3.264(16)nm3。由 4296个可观察衍射点进行全矩阵最小二乘法修正后 ,可靠性因子 R=0.0646。变温 ESR研究表明随温度降低单电子离域程度减小。     

新型双钼酸盐红色荧光粉的制备及发光性能研究

采用高温固相法合成了一种新型的白光LED用双钼酸盐红色荧光粉,利用XRD,F-4500等对其进行了研究。结果表明:该系列荧光粉可以被近紫外光(396 nm)和蓝光(466 nm)有效激发,发射峰值位于615 nm(Eu3+离子的5D0→7F2跃迁)的红光;而且在钾铕双钼酸盐荧光粉KEu(MoO4)2中引入适量的钨酸能加强其发光强度,而不改变样品的发射光谱的形状和发射峰的位置。此外,在确定WO24-/MoO42最佳比值的前提下,文章还详细探讨了碱金属离子相互置换对样品发光性能影响的机制。     

一维交替链状稀土配位聚合物[Er(dpa)(pya)(H2O)]n和[Nd2(pya)6(H2O)4]n的水热合成及结构表征

在水热条件下，稀土氧化物与2，2′-联苯二甲酸及异烟酸反应得到了两个新颖的一维交替链状配位聚合物[Er(dpa)(pya)(H₂O)]_n和[Nd₂(pya)₆(H₂O)₄]_n(H₂dpa=2，2′-联苯二甲酸；Hpya=异烟酸)。测定了它们的晶体结构，并进行了红外光谱和元素分析等 性质的表征。晶体结构测定表明这两个化合物同属单斜晶系，并具有相同的空间群P2₁/n， 晶体学参数分别为配合物1：a= 0.8830(3) nm，b=1.058 5(3) nm，c=2.089 1(6) nm，β=98.429(4)°，D_c=1.883g·cm^-3， V=1.931 4(10) nm³，Z=4； 配合物2：a=0.968 9(4) nm，b=1.978 3(9) nm，c=1.164 2(6) nm，β=112.106(7)°，D_c=1.756 g·cm^-3，V=2.067 5(17) nm³，Z=4。     

一维链状锌配位聚合物[Zn(apy)( μ-OH)NO3]n的合成、晶体结构及荧光性质

本文合成了1个新的配位聚合物[Zn(apy)(μ-OH)NO3]n(apy=2-氨基嘧啶),并且通过元素分析、红外、荧光、和单晶X-射线进行了表征。标题化合物属于单斜晶系,P21/c空间群,a=0.715 48(14)nm,b=1.850 5(4)nm,c=0.645 68(13)nm,β=110.24(3)°,V=0.802 1(3)nm3,Z=4,R=0.028 4。在化合物中,每个Zn(Ⅱ)离子与氨基嘧啶配体的1个N原子、硝酸根的1个O原子,以及2个羟基氧原子配位,并展示出扭曲的四面体几何构型。2个相邻的Zn(Ⅱ)四面体单元通过羟基氧原子连接形成一维链状结构,该一维链进一步通过氢键和π-π堆积作用形成三维网状结构。室温荧光光谱测定表明该化合物在392 nm处有强的荧光发射。     

一维链状铜配位聚合物[Cu(bpb)(PPh3)2]n·nClO4·nCH2Cl2·nH2O的合成、晶体结构与荧光性质研究

A coordination polymer of [Cu(bpb)(PPh₃)₂]_n·nClO₄·nCH₂Cl₂·nH₂O(bpb=1,4-bis(pyridine-3-aminome-thyl)benzene) has been synthesized and characterized by elemental analysis, IR, TG, PL and X-ray single crystal diffraction. The title complex crystallized in triclinic with space group P1, a=1.065 8(4) nm, b=1.542 4(6) nm, c=1.690 8(6) nm, α=80.11(10)°, β=76.00(10)°, γ=82.72(10)°, and V=2.646 5(17) nm³, Z=2, R=0.068 4. In the title complex, each Cu(Ⅰ) ion displays a distorted tetrahedron coordination configuration, defined by two N atoms from two different bpb groups, and two P atoms from PPh₃. Two adjacent Cu(Ⅰ) tetrahedron units are linked into a one-dimensional chain by the bpb ligands, which are further connected by hydrogen bonds to form a two-dimensional layer structure. Furthermore, the solid-state fluorescent property of the title complex was studied at room temperature. CCDC: 743417.     

二维配位聚合物[Tb(1,4⁃bdc)1.5(phen)(H2O)]n的合成、晶体结构及对Fe3+离子的荧光检测

通过溶剂热反应成功合成出一种新型2D配位聚合物[Tb(1,4-bdc)_1.5(phen)(H₂O)]_n(1)(1,4-H₂bdc=对苯二甲酸;phen=菲咯啉)。对其进行了单晶X射线衍射、粉末X射线衍射、红外光谱、元素分析、荧光光谱表征。X射线衍射晶体学分析表明,配合物1结晶于三斜晶系P1空间群,2个相邻的Tb(Ⅲ)离子与4个1,4-bdc^2-通过—O—C—O—桥联成双核单元,并进一步通过1,4-bdc^2-桥联成二维层状结构。荧光实验证明配合物1可以通过荧光猝灭机制检测Fe₃₊,Ksv=8.39×10³ L·mol-1,检测限为0.017μmol·L^-1。     

Synthesis and crystal structure of the isotypic rare earth thioborates Ce[BS3], Pr[BS3], and Nd[BS3]

The orthothioborates Ce[BS₃], Pr[BS₃] and Nd[BS₃] were prepared from mixtures of the rare earth (RE) metals together with amorphous boron and sulfur summing up to the compositions CeB₃S₆, PrB₅S₉ and NdB₃S₆. The following preparation routes were used: solid state reactions with maximum temperatures of 1323 K and high-pressure high-temperature syntheses at 1173 K and 3 GPa. Pr[BS₃] and Nd[BS₃] were also obtained from rare earth chlorides RECl₃ and sodium thioborate Na₂B₂S₅ by metathesis type reactions at maximum temperatures of 1073 K. The crystal structure of the title compounds was determined from X-ray powder diffraction data. The thioborates are isotypic and crystallize in the orthorhombic spacegroup Pna2₁ (No. 33; Z=4; Ce: , , ; Pr: , , ; Nd: , , ) . The crystal structures contain isolated [BS₃]^3‐ groups with boron in trigonal-planar coordination. The sulfur atoms form the vertices of undulated kagome nets, which are stacked along [100] according to the sequence ABAB. Within these nets every second triangle is occupied by boron and the large hexagons are centered by rare earth ions, which are surrounded by overall nine sulfur species.     

Synthesis, crystal structure, and structural conversion of Ni molybdate hydrate NiMoO4·nH2O

The synthesis and crystal structure of NiMoO₄·nH₂O were investigated. The hydrate crystallized in the triclinic system with space group P−1, Z=4 with unit cell parameters of a=6.7791(2) Å, b=6.8900(2) Å, c=9.2486(2) Å, α=76.681(2)°, β=83.960(2)°, γ=74.218(2)°. Its ideal chemical composition was NiMoO₄·3/4H₂O rather than NiMoO₄·1H₂O. Under hydrothermal conditions the hydrate turned directly into α-NiMoO₄ above 483 K, giving nanorods thinner than the crystallites of the mother hydrate. On the other hand, it turned into Anderson type of polyoxomolybdate via a solid-solution process in a molybdate solution at room temperature.     

Synthesis, crystal structure and characterization of a 2-D network organic-inorganic hybrid polymer with [α-BW12O40]5? as building blocks

A two-dimensional network compound [Ce(DMF)₄(H₂O)][α-BW₁₂O₄₀]·H₂O·(HDMA)₂ (HDMA = protoned dimethylamine, DMF = N,N-dimethylformamide) was synthesized from α-H₅BW₁₂O₄₀·nH₂O, Ce(NO₃)₃·6H₂O and DMF and characterized by IR, UV spectra and TG-DTA. The result of the X-ray single crystal diffraction indicates that the crystal is monoclinic, space group P2₁/n, with unit cell dimensional: a = 1.1983(3), b = 2.4216(5), c = 1.9517(4) nm, β = 92.91(3)°, Z = 4, R ₁ = 0.07710, wR ₂ = 0.1416. Structural analysis indicates that every [Ce(DMF)₄(H₂O)]³⁺ building block is surrounded by three adjacent [α-BW₁₂O₄₀]⁵⁻ polyanions, meanwhile, every [α-BW₁₂O₄₀]⁵⁻ polyanion interconnects with three neighboring [Ce(DMF)₄(H₂O)]³⁺ subunits, by making use of which two-dimensional network structure can be constructed. The result of thermogravimetric analysis manifests that the title compound has two-stage weight loss and the decomposition temperature of the title polyanionic framework is 560°C. The electrochemical analysis shows the title polyanion has three-step redox processes in the pH = 4–7 media.     

二维配位聚合物[Cd(bix)2Cl2]n的合成、晶体结构与荧光性能研究

利用金属离子和多功能的有机配体的自组装过程构筑得到的金属-有机配位聚合物,由于具有丰富的拓扑结构及其在分子与离子交换、吸附、选择性催化、光电子、磁学性能、孔洞材料、非线性光学等领域具有潜在的应用价值而成为众多科学家研究的热点领域[1～10].文献已经报道了大量具有新型拓扑结构的化合物,如一维链状、梯形、铁轨型:二维正方形或长方形格子、双层结构、砖墙结构和蜂窝状结构:三维八面体和类八面体结构、金刚石结构等.     

基于2，5-二溴对苯二甲酸配体的锰/钴配合物的合成、晶体结构及性质

将有机物2,5-二溴对苯二甲酸(H₂L₁)作为主配体,2,2′-联吡啶(L₂)、1,10-菲咯啉(L₃)分别作为辅配体,通过溶剂热法与一水硫酸锰、六水合硝酸钴分别反应得到配合物[Mn₂(L₁)₂(L₂)₂(H₂O)₂]_n (1)和[Co₂(L₁)₂(L₃)₂(H₂O)₂]_n(2)。通过单晶X射线衍射法、荧光光谱、热重分析等测试手段对这2种配合物进行分析研究。结果表明配合物1是由Mn²⁺配位连接L₁^2-与L₂形成无限延伸的二维网络状结构,各层在分子间氢键和π-π堆积作用...     

基于2，5-二溴对苯二甲酸配体的锰/钴配合物的合成、晶体结构及性质

将有机物2,5-二溴对苯二甲酸(H₂L1)作为主配体,2,2′-联吡啶(L₂)、1,10-菲咯啉(L₃)分别作为辅配体,通过溶剂热法与一水硫酸锰、六水合硝酸钴分别反应得到配合物[Mn₂(L₁)₂(L₂)₂(H₂O)₂]_n (1)和[CO₂(L₁)₂(L₃)₂(H₂O)₂]_n (2)。通过单晶 X射线衍射法、荧光光谱、热重分析等测试手段对这 2种配合物进行分析研究。结果表明配合物 1是由 Mn²⁺配位连接 L₁^2-与 L₂形成无限延伸的二维网络状结构,各层在分子间氢键和π-π堆积作用下形成了三维网络状结构。配合物2是由CO²⁺配位连接L₁^2-和L₃形成的无限延伸的二维网络状结构,各层在分子间氢键和π-π堆积作用下形成三维网络状结构。且这2种配合物均具有良好的荧光性和热稳定性,配合物1和2的最大发射波长分别为355和365 nm。     

Synthesis, crystal structure and properties of a new organic-inorganic hybrid Dawson-like polyoxotungstate [Co(2,2''''-bpy)3]2[Co(2,2''''-bpy)2Cl][Co(2,2''''-bpy)2]H2-[SbW18O60]·4H2O

A new organic-inorganic hybrid polyoxometalate based on Dawson-like polyoxotungstate anion [SbW18O60]9-, formulated [Co(2,2'-bpy)3]2[Co(2,2'-bpy)2Cl][Co(2,2'-bpy)2]H2[SbW18O60]·4H2O (2,2'-bpy= 2,2(-bipyridine) has been synthesized from Sb2O3, Na2WO4, CoCl2, and 2,2'-bipyridine materials by hydrothermal method, and which was characterized by elemental analyses, IR, XPS, EPR, TG, and X-ray single crystal diffraction. Structure analysis shows that the polyoxoanion self-assembled under hydrothermal conditions consists of a Dawson-like polyoxotungstate cluster anion [SbW18O60]9- encapsulating a pyramidal {SbO3} group within the {W18} cluster cage. EPR spectra show that the high-spin octahedral CoⅡ and low-spin CoⅡ ions coexist in the title compound. Magnetic properties indicate that the compound is antiferromagnetic.     

Coordination environment of [UO2Br4] in ionic liquids and crystal structure of [Bmim]2[UO2Br4]

The complex formed by the reaction of the uranyl ion, UO₂²⁺, with bromide ions in the ionic liquids 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim][Tf₂N]) and methyl-tributylammonium bis(trifluoromethylsulfonyl)imide ([MeBu₃N][Tf₂N]) has been investigated by UV–Vis and U L_III-edge EXAFS spectroscopy and compared to the crystal structure of [Bmim]₂[UO₂Br₄]. The solid state reveals a classical tetragonal bipyramid geometry for [UO₂Br₄]²⁻ with hydrogen bonds between the Bmim⁺ and the coordinated bromides. The UV–Vis spectroscopy reveals the quantitative formation of [UO₂Br₄]²⁻ when a stoichiometric amount of bromide ions is added to UO₂(CF₃SO₃)₂ in both Tf₂N-based ionic liquids. The absorption spectrum also suggests a D_4h symmetry for [UO₂Br₄]²⁻ in ionic liquids, as previously observed for the [UO₂Cl₄]²⁻ congener. EXAFS analysis supports this conclusion and demonstrates that the [UO₂Br₄]²⁻ coordination polyhedron is maintained in the ionic liquids without any coordinating solvent or water molecules. The mean U–O and U–Br distances in the solutions, determined by EXAFS, are, respectively, 1.766(2) and 2.821(2) Å in [Bmim][Tf₂N], and, respectively, 1.768(2) and 2.827(2) Å, in [MeBu₃N][Tf₂N]. Similar results are obtained in both ionic liquids indicating no significant influence of the ionic liquid cation either on the complexation reaction or on the structure of the uranyl species.