A New Series of Charge-assisted Hydrogen-bonded Host Frameworks Based on [Co（en）_3]~（3＋）and Dicarboxylates

A new series of metal complex carboxylates(MCC)made of [Co(en)3]3+(MC)and either 2,6-naphthalenedicarboxylic(NDC)or 4,4-biphenyldicarboxylic(BPDC)were synthesized and structurally characterized.The four new compounds have a general formula(MC)2(C)3·n(guest)with the guests of dimethylformamide(DMF)and dimethyl sulfoxide(DMSO)and water.All the structures represent a pillared-layer type,where the layer consists of MC cations,carboxylate anions or water molecules via a large number of hydrogen bonds.The layers are pillared by the organic residues of NDC or BPDC,resulting in the inclusion cavities where the guest molecules reside.Although their topological structures are similar,they crystallize in different crystal structures due to the rearrangement of pillars and hydrogen-bonded layers.     

层状结构材料Ni2P2S6的室温固相合成与表征

通过室温固相反应合成了Ni₂P₂S₆层状结构材料,并经XRD和Raman光谱进行了表征.与传统的高温固相反应法相比较,该法具有反应速度快、能耗低、可得均相产物的优点.TG-DTA研究表明,Ni₂P₂S₆在空气中热氧化的终产物为Ni₂P₂O₇,中间态可能是Ni₂P₂O₆亚稳相.     

Lu2Si2O7∶Ce纳米晶的溶胶-凝胶法合成和闪烁性能

采用溶胶-凝胶法制备了Lu2Si2O7∶Ce纳米晶,利用X射线衍射(XRD)、扫描电镜(SEM)、荧光光谱仪、X射线激发发射谱仪对制备的Lu2Si2O7∶Ce纳米晶的晶相结构、微观形貌和光学性能进行了表征。结果表明,溶胶-凝胶法制备的Lu2Si2O7∶Ce前驱体在煅烧温度为1000℃时开始晶化,晶粒尺寸随着煅烧温度的升高而变大,1200℃煅烧2 h后的晶体颗粒均匀,分散性最优,平均晶粒尺寸约为28.9 nm,呈近球形;Lu2Si2O7∶Ce纳米晶的紫外吸收谱存在峰位分别为304 nm和350 nm两个吸收峰,源自于Ce^3+离子的4f→5d跃迁;光致发射谱和X射线激发发射谱都表现为典型的非对称双峰结构,归属于Ce^3+离子的5d^1→2F5/2和5d^1→2F7/2跃迁,Ce^3+离子的最佳掺杂浓度约为1%;荧光衰减时间约为37.2 ns,可满足高时间分辨X射线探测需要。     

Tunable terahertz plasmon in grating-gate coupled graphene with a resonant cavity

Plasmon modes in graphene can be tuned into resonance with an incident terahertz electromagnetic wave in the range of 1–4 THz by setting a proper gate voltage.By using the finite-difference-time-domain(FDTD)method,we simulate a graphene plasmon device comprising a single-layer graphene,a metallic grating,and a terahertz cavity.The simulations suggest that the terahertz electric field can be enhanced by several times due to the grating–cavity configuration.Due to this near-field enhancement,the maximal absorption of the incident terahertz wave reaches up to about 45%.     

VUV/UV/X-Ray Excited Luminescent Properties of Eu^3＋ and Pr^3＋ Doped BiSbO4

Absorption spectra of BiSbO4 are studied. The electronic structure calculated by the DFT shows that BiSbO4 is a semiconductor, with direct band gap 2.96 eV, which is consistent with UV-visible diffuse reflectance experiment. The host lattice emission band is located at 440 nm under VUV excitation. Eu^3＋ and Pr^3＋ doped samples have high luminescence efficiency in emitting red and green light, respectively. From the partial density of states, Eu^3＋ doped emitting spectrum, and the host crystal structure parameters, the relationship between structure and optical properties is discussed. It is found that the Eu^3＋ ions occupied Bi^3＋ sites, and there could be an energy transfer from Bi^3＋ ions to RE^3＋ ions.     

金属性Zintl相化合物RE_3Cu_3Sb_4(RE=Nd,Sm,Tb,Dy,Ho)的合成、结构及成键特性

用电弧熔炼方法合成了化合物ＲＥ３Ｃｕ３Ｓｂ４（ＲＥ＝ Ｎｄ,Ｓｍ ,Ｔｂ,Ｄｙ,Ｈｏ）, 采用粉末Ｘ射线衍射方法测定了其晶体结构。化合物属立方晶系,Ｙ３Ａｕ３Ｓｂ４ 类型, 空间群Ｉ４３ｄ（Ｎｏ．２２０）,皮尔森玛ｃＩ４０。晶胞参数：Ｎｄ３Ｃｕ３Ｓｂ４ ：ａ＝０．９６７４９（１） ｎｍ, Ｖ＝０．９０５６１（３） ｎｍ３;Ｓｍ３Ｃｕ３Ｓｂ４：ａ＝ －０．９６１４５（１） ｎｍ ,Ｖ＝０．８８８７５（３） ｎｍ３ ;Ｔｂ３Ｃｕ３Ｓｂ４： ａ＝０．９５３６２（１） ｎｍ , Ｖ＝ ０．８６７２１（３）ｎｍ３;Ｄｙ３Ｃｕ３Ｓｂ４： ａ＝０．９５０８８（１） ｎｍ , Ｖ＝０．８５９７５（３） ｎｍ３;Ｈｏ３Ｃｕ３Ｓｂ４ ： ａ＝０．９４８８（２） ｎｍ , Ｖ＝０．８５４１（５） ｎｍ３。每个单胞中包含４ 个化合式量。此结构中,Ｃｕ 原子均处于Ｓｂ 原子所形成的配位四面体中心, 这些共价结合的配位四面体通过共顶最终联接形成三维ＣｕＳｂ 网络,稀土原子则散布在网络之间的空隙中。化合物电荷平衡结构式可表示为ＲＥ３＋３ Ｃｕ１＋３ Ｓｂ３－４ , 化合物具有导电性, 为金属性Ｚｉｎｔｌ 相。原子成键具有典型过渡性。原子的“配位数”遵从配位环境规律。化合物的     

Luminescence Properties of Ca4GdO（BO3）3：RE （RE=Eu^3＋,Tb^3＋） under VUV Excitation

We experimentally investigated the VUV excitation luminescence properties of Ca4 GdO(B03)3 :RE (RE=Eu^3 , Tb^3 )Ca4GdO(BO3)3:Eu3 and Ca4GdO(BO3)3:Tb^3 emitted bright red and green colour light, respectively, under 172 nm excitation, resulting from the favorable position of the host absorption band (186 nm) and efficient energy transfer from Gd^3 to activators (e.g. Eu^3 or Tb^3 ) by means of secondary absorption in the Ca4GdO(BO3)3 matrix. The f-d transitions of Eu^3 and Tb^3 in the host lattice are depicted.     

具有新结构类型的化合物Csln[PO3(OH)]2的合成与结构

水热法合成了新结构类型化合物CsIn[P03(0H)]2,并通过单晶X-射线衍射表征结构.标题化合物空间群为P121/c1(No.14),晶体学参数为:M=439.69,mP56,a=0.532 86(6)nm,b=0.91653(7)nm,c=1.478 39(14)nm,β=93.849(9).,V=0.7204(1)nm3,Z=4,Dx=4.054 g·cm-3,μ=8.713 mm-1,F(000)=800,R1= 0.0325,wR2=0.0874.在该化合物中,2个In06八面体和4个PO4四面体形成交连的六元环柱,并沿a轴方向形成近六方密堆积并连接成Cs+离子占据的十二元环结构隧道,六元环和十二元环连接构筑了三维网络结构.与类似化学计量比化合物Na2In2[PO3(0H)]4·H2O比较,标题化合物中十二元环的形成明显取决于隧道阳离子的大小,其拓扑构造可看作扩展的6,3-网格连接,化合物RbIn[PO3(0H)]2与之同构.     

具有新结构类型的化合物CsIn[PO3(OH)]2的合成与结构(英)

水热法合成了新结构类型化合物CsIn[PO₃(OH)]₂，并通过单晶X-射线衍射表征结构。标题化合物空间群为P1 2₁/c 1 (No.14)，晶体学参数为：M_r=439.69，mP56，a=0.532 86(6) nm，b=0.916 53(7) nm，c=1.478 39(14) nm，β=93.849(9)°，V=0.720 4(1) nm³，Z=4，D_x=4.054 g·cm^-3，μ=8.713mm^-1，F(000)=800，R₁= 0.032 5，wR₂=0.087 4。在该化合物中，2个InO₆八面体和4个PO₄四面体形成交连的六元环柱，并沿a轴方向形成近六方密堆积并连接成Cs⁺离子占据的十二元环结构隧道，六元环和十二元环连接构筑了三维网络结构。与类似化学计量比化合物Na₂In₂[PO₃(OH)]₄·H₂O比较，标题化合物中十二元环的形成明显取决于隧道阳离子的大小，其拓扑构造可看作扩展的6，3-网格连接，化合物 RbIn[PO₃(OH)]₂与之同构。     

Na6In4[P7O24(OH)5]·4H2O的水热合成与表征

具有开放骨架结构的金属酸盐在作为微孔材料、非线性光学材料、催化剂载体和离子交换剂等方面具有应用前景 [1] .自从报道第一个具有微孔结构的磷酸铝 [2 ]以来 ,许多其它具有开放骨架结构的金属磷酸盐被合成出来 ,它们的性质和潜在的应用研究也备受关注 [3～ 8] .本文采用温和条件下的水热法 ,合成得到了具有螺旋链状结构的磷酸铟钠盐 [Na6 In4 [P7O2 4 ( OH) 5]· 4H2 O,并采用 X射线单晶衍射方法进行结构测定 ,其结构中包含了共顶角的多面体连接成的螺旋链 ,链间的连接形成多面体四元环和八元环 ,3个四元环围成了一个三配位氧为中心…