X-ray crystal structure of the 1∶2∶2 pentaethyleneglycol dimethyl ether(pentaglyme)∶dichloropicric acid∶water complex. Infrared studies of the 1∶2∶2 complexes with tri-, tetra-, and pentaglyme

The 122 pentaglymedichloropicric acidwater adduct crystallizes in two polymorphic forms. Polymorph I is triclinic, space groupP¯1; at –96°Ca=11.629(6),b=12.566(8),c=12.877(16)Å,=89.19(8),=83.76(8), =85.95(5)°,D _x =1.599 g cm^–3,V=1866(5)ų,Z=2. Refinement on 7729 observed reflections yielded a finalR value of 0.045. Polymorph II is orthorhombic, space groupP2₁2₁2₁; at –87°Ca=13.631(7),b=26.441(8),c=5.182(6)Å,D _x =1.597(3) g cm^–3,V=1868(3)ų,Z=2. Refinement of 1610 observed reflections yielded a finalR of 0.071 for a disordered structure. The hydrogen bonding pattern in I is similar to that found in the analogous 18-crown-6 complex. Two pairs of alternate O atoms in the polyether are hydrogen bonded to two water molecules, each of which is hydrogen bonded to the phenol O atom of a neutral dichloropicric acid molecule. The bond distances and torsion angles in the S shaped polyether are similar to those in the cyclic polyether with C-C-O-C angles near 180° and O-C-C-O near±60°. The complex in II resembles that in I in overall shape and dimensions, also having normal bond distances and angles. The nonhydrogen atoms in water and the dichloropicric acid can be located unambiguously. However, the polyether molecule is disordered, and a satisfactory model for the disorder could not be found. Comparison of the IR spectra of the 122 tri-, tetra-, and pentaglymedichloropicric acidwater complexes suggests that the hydrogen-bonding in the tetraglyme complex is weaker than in the pentaglyme complex, but that in the triglyme complex is as strong or stronger.Deceased, March, 1993.     

Structure of sodium bis(pentadecatungstodiphosphato)diaquatetrazincate hydrate (16∶1∶50)

Crystals of Na₁₆[Zn₄(H₂O)₂(-P₂W₁₅O₅₆)₂]·50H₂O are triclinic, , witha+14.670(5),b+14.661(5),c+19.817(3)Å, =84.95(3), =81.51(3), =65.73(3)^o. Least-squares refinement converged atR+0.053 for 5906 independent data withl>3(I). The centrosymmetric anion consists of two -P₂W₁₅O ₅₆ ^12– ligands attached to a planar group of four Zn²⁺, two of which also carry water molecules. The distortions in the ZnO₆ octahedra and in the W₁₅ framework of the ligands are smaller than the corresponding distortions in the otherwise similar [Cu₄(H₂O)₂(P₂W₁₅O₅₆)₂]^16– anion.     

Zn∶Mn∶Fe∶LiNbO_3晶体的非挥发性存储

以Czochralski技术生长不同Li/Nb比Zn∶Mn∶Fe∶LiNbO3晶体。测试晶体抗光散射能力,Li/Nb=1.38的Zn∶Mn∶Fe∶LiNbO3晶体抗光散射能力比Fe∶LiNbO3高一个数量级以上。以二波耦合光路,双波长(蓝光-红光)存储技术,测试晶体全息存储性能,结果表明双波长存储性能优于双色存储。双波长(蓝光-红光)(476nm)的光激载流子是空穴。Mn离子是浅能级,Fe离子是深能级。采用Li/Nb=0.94和1.05的Zn∶Mn∶Fe∶LiNbO3晶体作为存储介质,以双波长(蓝光-红光)进行非挥发存储实验,它的非挥发衍射效率和响应速度高于双色存储。     

In∶Ce∶Cu∶LiNbO_3晶体的生长及存储性能研究

在Ce∶Cu∶LiNbO3 晶体中掺进In2 O3 ,用CZ法首次生长In∶Ce∶Cu∶LiNbO3 晶体。对晶体的抗光折变能力、红外光谱、指数增益系数、衍射效率和响应时间进行了测试 ,结果表明 :In(3mol% )∶Ce∶Cu∶LiNbO3 晶体的抗光折变能力比Ce∶Cu∶LiNbO3 提高两个数量级 ,其OH-吸收峰由LiNbO3 的 3484cm-1移到 35 0 8cm-1,响应速度比Ce∶Cu∶LiNbO3 晶体快三倍。对In∶Ce∶Cu∶LiNbO3 晶体抗光折变能力提高的机理、红外光谱OH-吸收峰紫移的机理进行了研究     

Structure of progesterone hydroquinone monohydrate (1∶1∶1), C21H30O2·C6H6O2·H2O

The crystal structure of progesterone hydroquinone monohydrate was determined by means of X-ray diffraction methods:M _r=442.6, orthorhombic,P2₁2₁2₁,a=14.680(2),b=22.725(3),c=7.334(1) Å,V _a=2446.6(6) ų,Z=4,D _x=1.190 M gm^–3, MoK radiation ,(MoK)=0.75 cm^–1,F(000)=948. The structure was solved usingMultan;R=0.059,R _w=0.059 for 2736 reflections. This progesterone molecule has the most flattenedA ring, relative to the rest of the skeleton, of all progesterone molecules studied so far. Steroid, hydroquinone, and water molecules form, by means of hydrogen bonds, two parallel chains connected with each other by hydrogen bonds.The authors thank Dr. A. Szyczewski for supplying crystals. This research was supported by the project RP.II.10 from the Polish Ministry of National Education and by PHS Grant No. DK26546.     

Yb∶LuxY1-xPO4混晶的生长及成分分析

用Pb2P2O7作为助熔剂采用自发成核的方法生长了Yb∶ LuxY1-xPO4混晶;X射线粉末衍射分析显示Yb∶LuxY1-xPO4晶体为四方磷钇矿结构;用光学显微镜观察了混晶的形貌,发现(100)面为混晶的解理面.红外分析表明助熔剂没有掺杂进晶体内部;根据电子显微探针分析数据,晶体分子式近似可以写成Yb0.05Y0.475Lu0.475PO4.     

Er∶Yb∶YCOB晶体制备及其激光二极管抽运激光特性

研究了Er∶Yb∶YCa4O(BO3)3(简称Er∶Yb∶YCOB)的多晶制备和单晶生长,用提拉法生长出光学质量优良的Er∶Yb∶YCOB单晶,测量了其吸收光谱和荧光光谱,分析了其能级和泵浦原理,并进行了以激光二极管为抽运源的激光试验,实现了Er∶Yb∶YCOB晶体的在1.55μm附近110mW的激光输出,且斜效率达18.9;.     

The 1∶1-adduct of chlorotriphenyltin with 2′,6′-dimethoxyflavone: a potential fungicide

The 11 adduct of chlorotriphenyltin with 2,6-dimethoxyflavone, (C₃₅H₂₉O₄ClSn)Mr=667.78, crystallizes in the triclinic space groupP1 with the following data:a-9.094(2),b=12.369(3),c=14.674(3) Å, =74.78(2), =77.00(2), =73.06(3)°,V=1503.8(4) ų,Z=2, Mo-K, =9, 8 cm^–1,Dc=1.475 g cm^–3, F(000)=676,T=293K. The structure was solved by direct-methods and has been refined to a finalR value (l>3(I)) of 0.0301. The flavone coordinates to the tin atom through the carbonyl oxygen atom. The metal center exhibits a trigonal bipyramidal configuration with the three phenyl groups in equatorial positions.     

Zn∶In∶LiNbO3晶体抗光损伤性能的研究

在LiNbO3中掺进ZnO和In2O3以Czochralski技术生长Zn∶In∶LiNbO3晶体.采用光斑畸变法测试Zn∶In∶LiNbO3晶体抗光损伤能力.Zn∶In∶LiNbO3晶体抗光损伤能力比LiNbO3晶体提高二个数量级.测试晶体的红外光谱,Zn∶In∶LiNbO3晶体吸收峰的位置相对LiNbO3晶体发生紫移,且随着Zn2+和In3+浓度增加紫移程度增加.晶体的倍频性能(相位匹配温度和倍频转换效率)研究表明:Zn∶In∶LiNbO3晶体相位匹配温度在室温附近.并研究了Zn∶In∶LiNbO3晶体抗光损伤机理和OH-吸收峰紫移的机理.     

Eu∶Zn∶LiNbO3晶体全息存储性能的研究

在LiNbO3中掺进Eu2O3和ZnO生长Eu∶Zn∶LiNbO3晶体.采用二波耦合光路测试晶体的指数增益系数和衍射效率.以Eu∶Zn∶LiNbO3晶体作为存储元件,实现了全息关联存储.     

对LiNbO3∶Cu∶Ce和LiNbO3∶Fe晶体非挥发全息存储灵敏度的研究

以双中心模型为基础,理论研究了LiNbO3∶Cu∶Ce和近化学计量比LiNbO3∶ Fe晶体在稳态情况下的非挥发全息存储灵敏度.通过考虑了两个晶体在其深能级和浅能级中心之间所有可能的电子交换过程,理论结果显示在低光强连续光范围内LiNbO3∶Fe晶体比LiNbO3∶ Cu∶ Ce晶体有着更高的记录灵敏度.并且通过研究文中得到的记录灵敏度的解析表达式,发现灵敏度与晶体浅能级上可激发离子数密度和泵浦光光强成正比.此外,采用较短波长的泵浦光和更大深能级数密度的晶体是另两种改变晶体灵敏度的方式.     

KMgF3∶Sm2+∶Li+晶体的色心分析

利用提拉法多次生长了KMgF3∶Sm2+和KMgF3∶Sm2∶Li+晶体;在KMgF3∶Sm2晶体结构分析的基础上,通过测试和分析KMgF3∶Sm2+和KMgF3∶Sm2+∶Li+晶体的激发光谱、发射光谱以及衰减曲线,揭示了晶体的7 F0→5D0激发光谱中,680 ～ 682 nm范围内未被揭示的一个激发峰的产生机理.最后得出结论该激发峰是由Li+引起的HA色心,此结论通过355 nm紫外光照射对光谱的影响进一步得到了确认.     

激光晶体Zr∶Yb∶LiNbO3的生长及光谱性质研究

采用Czochralski技术分别生长了双掺Zr4+(1mol;,2mol;,3mol;)和Yb3+(0mol;,1mol;,1mol;)的Zr∶Yb∶LiNbO3晶体.测试了晶体的XRD图谱并与标准图谱进行了比较.测量了晶体的红外透射光谱,OH-的振动吸收峰分别位于3485 cm-1、3488 cm-1和3488 cm-1,当Zr4+浓度达到2mol;以后,继续增大Zr4+浓度,OH-的振动吸收峰不发生移动.研究了晶体的室温吸收、发射光谱和荧光寿命特性,表明Zr∶Yb∶LiNbO3晶体是一种潜在的可用来发展具有抗光损伤的新型激光晶体材料.     

Crystal and molecular structure of the H-bonded complex between 1-chloro-2-hydroxynaphthalene-3-carboxylic acid and dimethylformamide (1∶1)

Crystal structure determination of the title complex reveals that the dimethylformamide solvent is bound to the carboxylic function of the hydroxy acid, in the form of a 7-membered hydrogen-bonded loop involving both the expected O-HO and an apparently weak C-HO interaction between host and guest. There is a strong intramolecular hydrogen bond between the phenolic OH and the carbonyl oxygen. Close packing of the complex units is afforded by a herringbone type alignment of host molecules.     

Urea-glutaric acid (2∶1) structural aggregates as building blocks for crystal engineering

The crystal structure of a 21 urea-glutaric acid cocrystal has been determined. The crystal is monoclinic:C2lc,a=11.954(5),b=10.932(1),c=9.078(3) Å, =97.86(3)°, withZ=4. The formula unit is a hydrogen-bonded heterotrimeric aggregate consisting of one acid subunit locked between two identical urea subunits. The symmetric arrangement from both sides of the acid allows for retaining the twofold axis primary inherent for the glutaric acid. An additional symmetry element (inversion center) is introduced during the aggregate self-association into one-dimensional chains, which are further organized through glide operations into a well-defined three-dimensional, hydrogen-bonded crystal network.Deceased on June 10, 1992.     

1英寸Cs2LiLaBr6∶Ce闪烁晶体的生长及性能研究

Cs₂LiLaBr₆∶Ce(CLLB∶Ce)晶体n/γ双读出闪烁性能优异,其实用化瓶颈在于大尺寸、高光学质量晶体的生长。本研究采用非化学计量比配比,避开CLLB∶Ce非一致熔融组分区域,通过改进研制坩埚下降法晶体生长炉,并优化温度场和降低坩埚下降速度等晶体生长工艺,从而克服组分过冷,保持生长界面稳定,得到了直径1英寸(1英寸=2.54 cm)的CLLB∶Ce晶体毛坯,等径透明部分长度达40 mm,单晶比例由52%提高至79%,可见光区光学透过率达到70%以上。在¹³⁷Cs激发下能量分辨率达3.7%,在²⁵²Cf激发下晶体的品质因子达到1.42,可以很好地甄别中子和γ射线。     

SiO2对Eu3+∶ZnO1-xSx红色发光材料的影响

采用溶胶凝胶-沉淀法,制备了掺杂Eu3+的ZnO1-xSx-SiO2发光材料,通过红外光谱、XRD、TEM、EDS以及激发光谱、发射光谱研究了材料的结构与发光性能,重点研究了SiO2的引入对发光材料发光性能的影响.结果 表明:材料中主要存在Si-O-Si键、Zn-S键和Si-O4基团,引入SiO2能改善材料的发光性能.并确定材料制备时最佳退火温度为800℃,当材料中S的含量为2.4at;,材料的最佳激发波长为395 nm.最后依据结构解释了材料的发光机理.     

α轴向生长Nd∶MgO∶LiNbO3单晶光纤的包层及特性

通过镁离子内扩散方法，实现了沿α轴向生长的掺镁汝铌酸锂单晶光纤具有阶跃和抛物折射率分布的芯－包层波导结构。对包层晶纤的损耗进行了测量，测得其耗为１．８０ｄＢ／ｃｍ，即比包层前晶纤损耗降低了约６倍。对包层晶纤的传输模块进行了观察，得到了低次模模传输的好结果。     

Zn2+∶Yb3+∶LiNbO3晶体生长及光谱性能研究

采用提拉法成功生长了Zn2+(2mol;)单掺的同成分铌酸锂(Zn2+∶LiNbO3)晶体及Zn2+(6mol;)和Yb3+(1 mol;)双掺的同成分铌酸锂(Zn2∶Yb3+∶LiNbO3)晶体,晶体尺寸分别约为φ30 mm×40 mm和φ30 mm×50mm.测试了这两个晶体的XRD图谱并与标准图谱进行了比较.测量了Zn2∶LiNbO3和Zn2∶Yb3+∶LiNbO3晶体的红外透射光谱,OH-的振动吸收峰分别位于3484.2 cm-和3493.7 cm-1,表明Zn2+的掺杂浓度还都处在阈值以下.研究了Zn2+∶Yb3+∶LiNbO3晶体的室温吸收、发射光谱和荧光寿命特性,表明其是潜在的近红外激光增益介质,有望发展新型功能激光器件.     

高密度闪烁体Nd∶GdTaO4和Nd∶LuTaO4发光跃迁强度计算

GdTaO₄和LuTaO₄是具有快发光衰减的新型重闪烁体。采用全谱拟合方法拟合了808 nm 激光二极管(LD)激发的M相Nd∶GdTaO₄和M′相Nd∶LuTaO₄的光致发光谱,给出了它们的跃迁强度参数A^k_t,p。在808 nm 激光激发下,GdTaO₄中Nd³⁺离子⁴F_3/2能级的上下两个晶场子能级的粒子布居数比例接近1,而在Nd∶LuTaO₄中则为1.30、1.41,表明在808 nm激光激发下,Nd³⁺的⁴F_3/2两个晶场子能级间的无辐射弛豫速率与激发速率相近。通过给出的跃迁强度参数A^k_t,p计算了Judd-Ofelt跃迁强度参数Ω_t,计算了Nd³⁺在GdTaO₄、LuTaO₄中的²P_3/2跃迁几率,表明GdTaO₄和LuTaO₄中Nd³⁺的数百纳秒发光跃迁是由高的无辐射跃迁几率导致的快发光衰减。