从双金属配位聚合物到一维Ag@Co_3O_4纳米复合催化材料

以合成的双金属配位聚合物Co(MAA)_2/Ag(Ⅰ)纳米带为前驱体,制备了一维Ag@Co_3O_4纳米复合催化材料.采用傅里叶变换红外光谱(FTIR)、核磁共振氢谱(1H NMR)、粉末X射线衍射分析(XRD)、扫描电子显微镜(SEM)及透射电子显微镜(TEM)等方法对其结构进行了表征,结果表明,Ag纳米晶体和Co_3O_4纳米晶体均匀分布在Ag@Co_3O_4纳米带上.采用紫外-可见吸收光谱(UV-Vis)等方法考察了Ag@Co_3O_4纳米复合材料在亚甲基蓝(MB)染料还原反应中的催化性能,发现其具有良好的催化活性、循环稳定性及磁分离能力.     

硅酸镓镧族非线性光学晶体

中红外非线性光学晶体可以实现中红外激光频率转换、拓展激光波长,在民用和军用领域中有至关重要的应用价值。其中,硅酸镓镧族晶体具有透过范围宽、激光损伤阈值高、晶体质量好等优势,引起了国内外同行的广泛关注。在这篇综述中,我们基于现有的实验数据,研究和分析了三种重要的硅酸镓镧族晶体La_3Ga_5Si O_(14)(LGS)、La_3Ga_(5.5)Nb_(0.5)O_(14)(LGN)、La_3Ga_(5.5)Ta_(0.5)O_(14)(LGT)的综合性能,详细总结了它们在电光调Q开关和中红外光参量振荡以及差频激光输出方面的应用。最后,本文还讨论了今后硅酸镓镧族中红外非线性光学晶体的重点发展方向。     

KTbP_4O_(12)晶体的生长及其荧光特性

本文采用蒸发溶液法从磷酸溶液中生长了KTbP_4O_(12)和一系列KLa_(1-x)TbxP_4O_(12)晶体。讨论了晶体生长中的物理化学问题。测定了晶体的X射线衍射图和红外光谱,发现KTbP_4O_(12)晶体存在着α和β两种不同的结构类型。计算了不同结构类型晶体的晶胞参数。 测定了晶体的荧光光谱,观察到在KLa_(1-x)Tb_xP_4O_(12)晶体中随着La~(3+)离子浓度的变化而有规律的变化。观察到KTbP_4O_(12)能发出强的绿色荧光,将可能作为一种新的晶体发光或激光材料。     

Ag-V氧化物系催化剂的结构、酸、碱性质及其对甲苯氧化的催化性能

应用X射线衍射、红外吸收光谱、脉冲色谱等技术,研究了Ag-V氧化物系催化剂的体相结构和表面酸碱性质及其与甲苯氧化合成苯甲醛的活性和选择性的关系。试验结果表明在V_2O_5中引入Ag后,催化剂的比活性下降,选择性提高,在 V/(V+Ag)=0.7(原子比)时,生成苯甲醛的选择性最高。X射线衍射分析指出其主要晶相结构Ag_(0.80)V_2O_5δ和Ag_(0.5)V_(2)O_5β。红外吸收光谱表明在900～1000cm~(-1)间有较强的吸收峰出现。Ag-V氧化物催化剂表面具有酸碱性,Ag的引入使酸度降低,碱度增高。而催化剂的组成、表面酸碱度与催化活性和选择性之间有良好的顺变关系。     

TbP_5O_(14)中Tb~(3+)离子~5D_4,~7F_J(J=0—6)的Stark能级

本文测定了五磷酸铽单晶在77K下的偏振荧光光谱和红外吸收光谱。根据这些光谱,~5D_4,~7F多重态的能级结构以及跃迁归属已被确认。从X光结构分析的结果,该晶体中Tb~(3+)离子与八个近邻的氧原子相配位,呈稍歪扭的正方反棱柱体。换句话说,在TbP_5O_(14)中Tb_(3+)离子的局部对称性属于C_(4v)。按该对称性,利用配位场理论所做的计算与实验观察的~7F_J(J=0—6)多重态的Stark分裂得到了相当好的符合。其结果是,均方根差为8.4cm~(-1),最大偏差为17cm~(-1)。     

掺锰五磷酸铈、铽晶体的生长及其光谱

用蒸发溶液法从磷酸溶液中首次生长出一系列Ce_xTb_(1-x)P_5O_(14):Mn晶体。它们属于单斜晶系,空间群P2_1/c。计算了晶格常数,用EPR结果确定在晶体中锰离子呈二价。测定了Ce_xTb_(1-x)P_5O_(14):Mn晶体的光谱,说明在晶体中存在着Ce~(3+)到Tb~(3+)和Mn~(2+)的能量转移。Mn~(2+)和Tb~(3+)的发射峰重叠,并使Tb~(3+)的发射峰增强。     

氯化钯与4-(2-吡啶偶氮)间苯二酚、硫酸四苯锑形成的离子缔合物的结构与性质研究

本文对离子缔合物[(C_6H_5)_4Sb~+,PdCl(C_(11)H_7N_3O_2)~-]进行了制备,经元素分析、红外光谱和核磁共振谱分析,确定了络合物的组成和结构,并测定了其吸收光谱、电导率和稳定常数。考察了络合物在水中的存在状态及其电荷性质,并对其形成机理进行了初探。     

钕激光晶体结构,组成和光谱特征研究

本文在考虑交叉弛豫过程的情况下,研究了含Nd~(3+)激光晶体Y_3Al_5O_(12)YAlO_3,LiYF_4和NdP_5O_(14)的辐射跃迁几率、荧光寿命和荧光分支比,解速率方程得到了各能级上粒子数和Nd~(3+)浓度的关系,讨论和比较了四种激光晶体的光谱特征。     

磷对泥/煤混燃灰熔融特性的影响及矿物相演变规律

采用灰熔点仪、X射线荧光仪(XRF)研究了无机非金属P2O5对城市污水污泥与烟煤的混烧灰熔融特性的影响,利用X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)研究在各混烧温度下灰中含磷矿物在晶体和非晶体间的演变。结果表明,对于Al_2O_3含量较多且熔点较高的灰样,磷含量的增加可显著降低其灰熔点,P2O5含量在0-4%时影响最大,使其灰熔点降低126℃;但对碱性含量高的灰样的影响较小。低温灰中主要以磷酸铝(AlPO_4)晶体为主,温度升高后,与硬石膏(CaSO_4)等含钙矿物和赤铁矿(Fe_2O_3)反应生成晶体Ca_3(PO_4)_2和玻璃相(Fe_2O_3)_(0.252)(P_2O_5)_(0.748),磷含量增加可使灰中玻璃相(Fe_2O_3)_(0.252)(P_2O_5)_(0.748)增加,是磷降低灰熔点的主要原因。     

水合苯并—15—冠—5四溴合铟(Ⅲ)酸钠(NaInBr_4)_2(C_(14)H_(20)O_5)_3·2H_2O的晶体结构

本文报道了在乙醇—氯仿混合溶剂中首次获得组份为(NaInBr_4)_2(C_(14)H_(20)O_5)_3·2H_2O的晶体配合物.用元素分析确定了其组份.通过红外光谱的研究证实配合物晶体中的阳离子与醚氧原子及水分子发生了配合作用。 用X-射线衍射法测定了配合物的晶体结构,晶体属单斜晶系,M=1755.3,a=14.393(8)A,b=28.494(9)A,c=15.191(8)A,β=96.63(5)°,V=6189A~3’,D_c=1.88g·cm~(-3),Z=4,空间群为C_(2h)~5——P2_1/n。晶体结构研究表明不对称单位中包含两个配阳离子Na~(+)(B15C5)(B15C5)代表C_(14)H_(20)O_5分子)。两个配阴离子InBr_4~-、两个H_2O分子和一个未被金属离子配合的B15C5分子。配合物的晶体结构测定结果对于阐明与该晶体相对应的萃取体系In(Ⅲ)/NaBr/B15C5—1,2C_2H_4Cl_2的萃取机理提供了理论依据。     

钙钛矿型(La_(0.8)M_(0.2))MnO_3和(La_(0.8)Sr_(0.2))(Mn_(1-x)Fe_x)O_3的XRD和IR光谱的研究

合成了（La0.8M0.2）MnO3（M=Ca2+，Sr2+，Ba2+）和（La0.8Sr0.2）（Mn1-xFex）O3（x=0．1、0．2、0．3、0．4、0．5）两类氧化物，经XRD确认为钙铁矿型氧化物，应用FT－IR对其进行研究，对主要的红外特征振动υ（Mn-O）和δ（O-Mn-O）进行分析表征。这类化合物的υ（Mn-O）和δ（O-Mn-O）的FT－IR特征吸收峰十分相似，但在～608cm－1处出现较大差别，以Sr2+、Ca2+和Ba2+部分A位取代La3+的钙铁矿型氧化物和B位Fe取代Mn时，由于离子的溶解能不同，对晶格的有序排列的影响程度不一，导致了Mn－O键的键力场不同，引起了吸收峰向低波数移动。这种结构上的差异，导致对汽车尾气中的有害成份碳氢化合物（HC）和一氧化碳（CO）的催化氧化能力降低。借此可以用于研究结构与催化性能的关系。     

Structure and spectroscopy of Tb[Au(CN)2]3.3H2O

The compound Tb[Au(CN)2]3.3H(2)O crystallizes in a layered structure in the hexagonal space group P6(3)/mcm with the 9-coordinate environment of Tb3+ comprising six (CN)- and three OH2 in a tricapped trigonal prism. The shortest Au...Au distance is 3.31 angstroms. The vibrational spectra show that the series Ln[Au(CN)2]3.3H2O (Ln = Y, Pr, Sm, Eu, Tb) are isostructural. The electronic spectra of Eu[Au(CN)2]3.3H2O clearly show that Eu3+ occupies one site of spectroscopic site symmetry D3h, in agreement with the crystallographic data. The electronic emission and absorption spectra of Tb[Au(CN)2]3.3H2O have been recorded at temperatures down to 1.5 K, and the f-f pure electronic transitions are interpreted in detail as arising from the lowest electronic states (in D3h symmetry) (7F6)E' in absorption and (5D4)E' in emission. At low energy, further bands are assigned to the vibronic structure of the CN stretching and water stretching modes, with the latter more predominant. Although the CN stretching vibrations show exclusive infrared or Raman activity in Tb[Au(CN)2]3.3H2O, both of these infrared and Raman active modes are observed in the two-center vibronic transitions. The reasons for this are discussed.     

Crystallization kinetics and excess free energy of H2O and D2O nanoscale films of amorphous solid water

Temperature-programmed desorption (TPD) and reflection absorption infrared spectroscopy (RAIRS) are used to investigate the crystallization kinetics and measure the excess free energy of metastable amorphous solid water films (ASW) of H(2)O and D(2)O grown using molecular beams. The desorption rates from the amorphous and crystalline phases of ASW are distinct, and as such, crystallization manifests can be observed in the TPD spectrum. The crystallization kinetics were studied by varying the TPD heating rate from 0.001 to 3 K/s. A coupled desorption-crystallization kinetic model accurately simulates the desorption spectra and accurately predicts the observed temperature shifts in the crystallization. Isothermal crystallization studies using RAIRS are in agreement with the TPD results. Furthermore, highly sensitive measurements of the desorption rates were used to determine the excess free energy of ASW near 150 K. The excess entropy obtained from these data is consistent with there being a thermodynamic continuity between ASW and supercooled liquid water.     

Infrared and computational investigation of vanadium-substituted Keggin [PVnW12-nO40](n+3)- polyoxometallic anions

This study investigates complex salts of [PW(12)O(40)](3-), [PVW(11)O(40)](4-), [PV(2)W(10)O(40)](5-), and [PV(3)W(9)O(40)](6-) Keggin anions using Fourier transform infrared spectroscopy under ambient atmospheric and high-vacuum conditions and by computational methods. A detailed vibrational study suggests that the presence and amount of vanadium in these anions can be tested quickly and reliably with the help of infrared spectroscopy because the salts of these anions exhibit distinctly different infrared absorption signatures (particularly in the 1025-1250 cm(-1) region, where the P-O stretch is surrounded by a set of complex vibrations involving V-O and W-O bonds). Investigation of these salts with different countercations suggests that the overall appearance of the spectra, and thus the ability to use infrared as a diagnostic tool to identify the presence and number of vanadium atoms in Keggin structure anions, is not affected significantly. Last, it is shown that all the structures investigated are extremely stable across a wide range of temperatures.     

Upconversion and fluorescence spectral studies of Er3+/Yb3+-codoped Bi2Q3-GeO2-Ga2Q3-Na2O glasses

The absorption spectra and upconversion fluorescence spectra of Er3+/Yb3+-codoped natrium-gallium-germanium-bismuth glasses are measured and investigated. The intense green (533 and 549 nm) and red (672 nm) emission bands were simultaneously observed at room temperature. The quadratic dependence of the green and red emission on excitation power indicates that the two-photon absorption processes occur. The influence of Ga2C3 on upconversion intensity is investigated. The intensity of green emissions increases slowly with increasing Ga2O3 content, while the intensity of red emission increases significantly. The possible upconversion mechanisms for these glasses have also been discussed. The maximum phonon energy of the glasses determined based on the infrared (IR) spectral analysis is as low as 740 cm-1. The studies indicate that Bi2O3-GeO2-Ga2O3-Na2O glasses may be potential materials for developing upconversion optical devices.     

邻菲罗啉-氨基酸铜(Ⅱ)配合物的合成及表征

合成了三种邻菲罗啉（Ｐｈｅｎ）－氨基酸酮（Ⅱ）的配合物：［Ｃｕ（Ｐｈｅｎ）（Ｌ－Ｈｉｓ）］·２ＣｌＯ４·Ｈ２Ｏ,［Ｃｕ（Ｐｈｅｎ）（Ｇｌｙ）］·ＣｌＯ４·Ｈ２Ｏ和［Ｃｕ（Ｐｈｅｎ）（Ｌ－Ｐｒｏ）］·ＣｌＯ４·０．５Ｃ２Ｈ５ＯＨ（Ｌ－Ｈｉｓ：组氨酸;Ｇｌｙ：甘氨酸：Ｌ－Ｐｒｏ：脯氨酸）。用元素分析、摩尔电导、ＩＲ和电子吸收光谱等手段对配合物进行了表征     

锂离子电池电解质溶液的研究

本文报道了 5磺基水杨酸苯氧基硼酸锂 (LiB(SO3 )C6H3 (O) (COO)OC6H5)的合成及其在乙烯碳酸酯 (ED) /二甲基碳酸酯 (DMC)及丙烯酸酯 (PC) /二甲基亚砜 (DMSO)混合溶剂中电化学性能的研究 .     

Crystal field splitting of rovibrational transitions of water monomers isolated in solid parahydrogen

We report polarized infrared absorption spectra of water isotopologues isolated in solid parahydrogen (pH2) which reveal the crystal field induced splittings of the 1 01<--0 00 R(0) lines in the nu1 HDO, nu3 D2O, nu3 HDO, and nu3 H2O fundamental bands. For annealed pH2 solids, these spectra also reveal a strong alignment of the hexagonal-close-packed crystallites' c axes with the deposition substrate surface normal. This alignment effect explains our failure to detect the parallel-polarized components of these R(0) lines in spectra of pH2 solids produced on a transparent deposition substrate [M. E. Fajardo et al., J. Mol. Struct. 695, 111 (2004)]. This lesson applies more generally to comparison of solid pH2 spectra obtained in different laboratories. The spectra are consistent with water monomers existing in solid pH2 as very slightly hindered rotors. The individual components of the R(0) absorption lines show a Lorentzian lineshape, with vibrational depopulation the most important source of line broadening.     

Tricarbonyls of low-coordinated Au(0) atoms in zeolite-supported gold nanoparticles: Evidence from infrared and X-ray absorption spectroscopies

Mononuclear gold complexes in zeolite NaY were synthesized from initially physisorbed Au(CH3)2(C5H7O2) and characterized by X-ray absorption and infrared spectra recorded as the samples were exposed to flowing CO. X-ray absorption spectra demonstrate the formation of zero-valent gold nanoparticles during the CO treatment. Three new nu(CO) bands grew in during this treatment, at 2070, 2033, and 2000 cm(-1), characteristic of carbonyls of Au0. Because the relative intensities of these bands decreased monotonically when the flow of CO was replaced by flowing He, it is inferred that they correspond to a single Au0(CO)3 species, on low-coordinated Au atoms. This is the first example of an Au0(CO)3 species.     

Infrared intensities of the external modes of crystalline nitrous oxide

The absorption intensities of two infrared active lattice modes of crystalline N₂O have been measured. Both the frequencies and intensities of the external modes of N₂O have been found to be very similar to those of CO₂, and most of the differences between the spectra of CO₂ and N₂O can be explained by the differences in the quadrupole moments.