Eu（DBM）3纳米微晶的低频喇曼光谱

低频喇曼（LFR）光谱技术广泛应用于无序体系的结构性质研究，它能提供有关微粒的非弹性振动、量子尺寸效应以及分形体的光散射性质等方面的信息［‘一句.尤其是通过LFR光谱的研究，可以确定分形体振动（频率为叫激发的光谱线数已用于描述分形结构的局域振动量子一分形子的态密度：N（川。0‘’‘，又称之为分形干线教，是联系“几何结构”与“动力学行为”的重要参数.对它进行深入而广泛地研究，将有可能为更深入地认识无序材料的物理、化学性质带来重大的突破，因而引起人们的极大兴趣.其研究工作主要集中于非晶态的硅溶胶和玻璃体系［…     

Eu(DBM)3超微粒子的光谱特性

The colloids of Eu(DBM)3 and ultrafine particles Eu(DBM)3 were perpared. The particle sizes determined by X-ray and by TEM measurements were in 7-30nm range. Their UV absorption and fluorescence spectra were compared with each other and with those of the solid sample. It was shown that the 5D1→7 F1,2 transition was observed in the colloids of Eu(DBM)3 at room temperature. The increase of the excited-state S1 and T1 energy, the peak positions of UV absorption shifted to shorter wavelength, the changes of the absoprtion coefficient with decreasing size were observed.     

含Eu(DBM)_3·H_2O纳米微晶的光学树脂的制备及性能研究

稀土β二酮的配合物因其具有Antenna效应,发光强度明显增强;而且它的激光性质也被证实[1] ,是应用价值极大的配合物.稀土配合物与高分子的复合,获得了兼具二者优良性能的功能材料,有很好的应用前景.通常二者的复合多采用直接掺杂、机械共混和熔融等方法.但由于二者的相容性较差,并且存在着浓度淬灭现象,使获得高稀土含量、分散均匀的聚合物发光材料非常困难.以往,杨柏小组分别采用直接掺杂和原位复合的方法制备了含稀土配合物的光学树脂[2 ,3 ] ,但稀土配合物含量受到限制.本文在文献[4,5 ]的基础上,采用化学沉淀的方法,制备了30～30 0nmEu…     

用喇曼光谱研究Na_5Eu(WO_4)_4单晶的晶格振动模式

本文研究了基质发光单晶Na_5Eu(WO_4)_4在几种几何配置下的喇曼光谱和红外光谱。用群论中位置群分析法讨论了它的内、外振动模式,并对实验振动Ag,Bg真和Eg真模的归属进行了指认。由于WO_4~(2-)离子团的拉伸振动能很高,在755～940cm~(-1)范围,它是产生Eu~(3+)的5~D_2→5~D_1和5~D_1→5~D_0多声子无辐射弛豫的原因。这导致了Eu~(3+)在室温下主要产生5~D_0→7~F_j的发光跃迁,这是Na_5Eu(WO_4)_4红色发光有很高色纯度的原因。     

包覆铕配合物Eu(DBM)3phen的硅胶纳米荧光检测材料的制备

以十六烷基三甲基溴化铵(CTAB)和一种短链氟碳阴离子表面活性剂(Capstone FS-66)作为双模板,通过四乙氧基硅烷(TEOS)和含氯官能团的硅烷偶联剂制备了含氯官能团的大孔径树枝状介孔二氧化硅纳米球(MSNs);利用EuCl3·6H2O、1,10-邻菲啰啉盐酸盐和二苯甲酰甲烷合成铕的配合物Eu(DBM)3phen,然后以MSNs为基质填充Eu(DBM)3phen。为了更好地将Eu(DBM)3phen嵌入到纳米球孔道内,对所制备的介孔纳米球的孔道表面进行聚乙烯亚胺(PEI)修饰;同时为了解决荧光配合物从孔道泄露的问题,在纳米球表面层层自组装吸附多层聚合物,然后包覆一层二氧化硅膜形成核-壳结构。最后将所制备的荧光纳米球与3-氨丙基三乙氧基硅烷反应,使其表面带有氨基,用来嫁接生物分子如抗体等。通过透射电子显微镜(TEM)、荧光光度计和傅里叶红外光谱仪(FTIR)等多种方法对最终合成的纳米球的结构和性能进行了表征。结果表明:本制备的荧光纳米球粒径约为230μm、荧光强度约为2800a.u,1543cm^-1处出现了氨基的弯曲振动峰。     

Synthesis and Photoluminescence of New Europium Complex Eu(DBM)3 (DPPZ) with Dipyridophenazine Ligand

Dipyrido[3,2-a:2′,3′-c] phenazine moiety has been introduced as neutral lignad in europium complex.Therefore a new europium complex with saturate emission,strong fluorescnet intensity and good solubility was designed and synthesized for the first time.Its photoluminescence and UV properties were examined.The experimental results showed that this new Eu-complex could be used as red electroluminescnet materials.     

对苯二胺和N-取代衍生物正离子自由基的共振喇曼光谱研究

本文中报道了对苯二胺和四种N-烷基取代衍生物正离子自由基的共振喇曼光谱, 揭示了自由基是具有明显C=C和C=N双键性质的半醌式结构, N原子上给电子基团的取代引起上述化学键振动峰低频移动, 反映出结构一端N上有烷基的自由基中与取代基直接相连的N原子失去一个p电子带正电荷, 并吸引环上的π电子形成一定程度C=N双键. 共振喇曼光谱随激发光波长的变化表明, 自由基的两个可见电子吸收带分别主要产生于环结构的π→π*和包含N原子结构的n→π*电子跃迁。     

人工神经网络在喇曼光谱数据处理中的应用

将人工神经网络（ａｒｔｉｆｉｃｉａｌｎｅｕｒａｌｎｅｔｗｏｒｋｓ）应用于喇曼光谱数据处理中。研究了学习时间常数μ（ｌｅａｒｎｉｎｇｒａｔｅｃｏｅｆｆｉｃｉｅｎｔｓ）及传递函数（ｔｒａｎｓｆｅｒｆｕｎｃｔｉｏｎｓ）对网络性能的影响，发现当μ＝０．５时，网络运行最佳。通过比较原始谱图及经网络处理后所得谱图，证明采用带有Ｓ形传递函数的前向网络能获得较好的信噪比，谱线的分辨率也有所提高。     

共振喇曼光谱研究稀土离子Er3对肌红蛋白结构的影响

随着稀土金属开发应用的不断深入 ,它的安全性已引起人们的广泛关注 .Evans[1]曾报道稀土化合物由于其类 Ca2 + 性导致各种负面生物效应 ,包括影响心血管功能及溶血 ,然而有关稀土离子影响血红素蛋白结构的研究尚很少见报道 .肌红蛋白由含 1 5 2个残基的单一多肽链 (珠蛋白 )和血红素组成 .在生物体中 ,它为肌肉组织贮存氧 ,以供细胞呼吸的需要 ,因此它在人体中具有极其重要的生理作用 .研究稀土离子对肌红蛋白的影响对了解稀土离子降低血红素蛋白载氧能力的作用机理具有实际意义[2 ] .由于血红素在可见和近紫外区有很强的吸收带 ,以氩离子…     

Eu(α-NMA)_3(α-HNMA)Phen的晶体结构及光谱研究

Eu(α NMA) 3(α HNMA)Phen (NMA =萘甲酸根 ;HNMA =萘甲酸 ;Phen =1,10 邻菲咯啉 )配合物晶体属三斜晶系 ,P1- 空间群 ,晶胞参数a =1.2 40 1( 3)nm ,b =1.30 5 6( 3)nm ,c =1.65 0 0 ( 3)nm ,α =73.0 1( 3)° ,β =82 .44( 3)° ,γ =62 .0 7( 3)° ,V =2 2 5 72 ( 8)nm3,Z =2 ,Dc=1.496g/cm3,F( 0 0 0 ) =10 2 6,R =0 .0 5 17.该配合物是双核分子 ,两个Eu(Ⅲ )离子通过 4个α 萘甲酸根的羧基桥联 .中心离子分别与五个羧基桥氧原子、一个螯合配位羧基的 2个氧原子和一个邻菲咯啉的 2个N原子配位 ,形成九配位的扭曲三帽三棱柱体 .双核分子中萘环与邻菲咯啉平面之间存在着π π相互作用 ,有利于该配位构型的稳定 .荧光光谱测定结果显示 ,标题配合物发光性能良好     

可见光响应的Co3(PO4)2/Ag3PO4纳米复合光催化剂的制备及表征

采用简单的化学偏聚法合成出Ag₃PO₄纳米颗粒、磷酸钴（Co₃（PO₄）₂,CoP）纳米片以及它们两者的纳米复合结构（CoP/Ag₃PO₄）,同时还比较了它们的可见光催化活性. 采用场发射扫描电镜（FESEM）、X 射线衍射（XRD）、紫外-可见（UV-Vis）吸收光谱以及光致发光谱等手段对其形貌、结构、光学以及可见光催化性能等进行表征. 结果表明,CoP/Ag₃PO₄复合纳米结构的可见光降解甲基橙（MO）的速率和循环稳定性均明显优于其它两种物质. 这表明CoP应该起着共催化剂的作用,它能够抑制光生电子与空穴之间的复合,并且提供大量高活性的光生空穴. 此外,我们还发现CoP/Ag₃PO₄降解另一种阳离子型染料——罗丹明B（RhB）的能力则远不如纯Ag₃PO₄,这可能是与光催化剂的表面性质发生改变有关,造成更低的RhB吸附能力. 本文提供了一种廉价制备高效可见光催化剂的新方法.     

反式2-甲基-2-丁烯酸甲酯与臭氧反应机理的计算研究

采用G3B3方法构建反式2-甲基-2-丁烯酸甲酯与O3反应体系以及后续Criegee自由基有、无水分子参与下异构化反应的势能面剖面.结果表明,反式2-甲基-2-丁烯酸甲酯与O3反应首先生成一个稳定的五元环中间体,此中间体按断键位置不同后续裂解反应存在两条路径,分别生成产物P1(CH3CHOO+CH3OC(O)C(CH3)O)和P2(CH3CHO+CH3OC(O)C(CH3)OO).利用经典过渡态理论(TST)并结合Wigner矫正模型计算了200-1200 K温度区间内标题反应的速率常数kTST/W.计算结果显示,294 K时,该反应速率常数为7.55×10-18cm3molecule-1s-1,与Bernard等对类似反应所测实验值非常接近.生成的Criegee自由基(CH3CHOO和CH3OC(O)C(CH3)OO)可分别与水分子发生α-加成及β-氢迁移反应,其中Criegee自由基与水的α-加成反应较其与水的β-氢迁移反应具有优势.另外与无水分子参与CH3CHOO和CH3OC(O)C(CH3)OO异构化反应相比,水分子的参与使得异构化反应较为容易进行.     

卟啉H2TSPP和Ag(II)TSPP吸附在均分散Fe3O4胶体上的拉曼光谱

Surface Enhanced Raman Scattering (SERS) of tetrasodium meso-tetrakis (4-sulfonatophenyl) porphine (H2TSPP) and silver tetraphenylporphyrin (Ag(Ⅱ)TSPP) adsorbed spontaneously on uniform Fe3O4 colloids are recorded. The enhancement of Raman bands is approximately 30. An analysis of the SERS spectrum shows that on the Fe3O4 surface H2TSPP takes its diacid form H42+TSPP.     

制备方法对WO3/ZrO2结构的影响

WO3/ZrO2 catalysts prepared from Zr(OH)4 and crystallized ZrO2 have been characterized by means of XRD, LRS (qualitative and quantitative), and the specific sufrace area has been measured. The influence of the preparation method, the contents of WO3 in the samples and the calcination tempearture on the specific surface areas of the samples, the phase of support and the structural states of active component has been studied. The results show: (1) WO3 can disperse on ZrO2 as a monolayer; (2) WO3 dispersed on Zr(OH)4 as a monolayer retards the crystalline growth of the support on calcination, makes it crystallizing into a metastable tetragonal modification, and prevents the inter- crystalline sintering between the crystallites of ZrO2. These factors would result in an increase in the specific surface area of WO3／ZrO2 prepared from Zr(OH)4. As the content of WO3 in the sample comes up to its monolayer capacity, this effect is displayed most fully. A chemical reaction can occur between WO3 and Zr(OH)4 (or the tetragonal ZrO2) at a high temperature(800℃),producing some superacid sites on the surface. By these views, the main experimental facts published in the literatures can been interpreted satisfactotily.     

C60离子束撞击固体表面的坍塌沉积(I)共焦显微拉曼光谱研究

Raman spectroscopy was applied to characterize the species deposited from the mass-selected C60 ion beam which was accelerated to 900 eV. The substrates for the deposition were (0001) surface of highly oriented pyrolitic graphite and (111) surface of gold crystal. The species do not exhibit the Raman scattering features of buckminsterfullerene, but displays peaks at 1585 and 1332 cm-1 instead. The former peak is the chararteristic Ranan peak of hexagonal graphite, and the latter can be attributed to the amorphous carbon in sp3 hybridization. The result reveals that C60 was collapsed to form a new phase when it collides on the solid surface.     

真空辅助法合成Fe_3(PO_4)_2·8H_2O及对LiFePO_4/C结构、形貌和电化学性能的影响(英文)

采用了一种真空辅助沉淀法制备Fe3(PO4)2·8H2O,并以此进一步合成粒径尺寸在400 nm左右LiFePO4颗粒.研究了Fe3(PO4)2·8H2O对于磷酸铁锂的形貌、结构、电化学性能的影响.X射线衍射(XRD)结果表明,真空辅助制备的Fe3(PO4)2·8H2O具有高纯度,以此制备的LiFePO4具有高结晶度和纯度.扫描电子显微镜(SEM)结果表明,真空辅助制备的Fe3(PO4)2·8H2O具有未完全发育的颗粒,以此制备的LiFePO4均匀无硬团聚.透射电子显微镜(TEM)结果显示真空辅助制备的LiFePO4包覆一层均匀的碳.真空制备的LiFePO4显示了优异的电化学性能,在1C、10C、20C倍率下的容量分别为140、113、100 mAh·g-1.真空制备的LiFePO4的循环伏安曲线显示了小的极化电压和尖锐的氧化峰.充放电平台曲线表明真空对LiFePO4高倍率性能起到重要作用.电化学阻抗谱(EIS)计算结果显示,真空和非真空制备的LiFePO4的锂离子扩散系数分别为1.42×10-13和4.22×10-14cm2·s-1,说明真空辅助能够提高LiFePO4的扩散系数.     

NH0-1+2-3离解能等的高级ab initio计算与评价

A recent experimental determination[1] of the dissociation energies (D0) for H2N-H, H2N+-H and H2N-H+, the ionization energies for NH3 and NH2 resulted in large deviations when compared with those of the earlier values and the QCISD(T)/6-311+G(3df,2p) ab initio calculations. We have performed some higher level ab initio calculations on these data by utilizing the Gaussian 92/DFT and Gaussian 94 pakages of programs and have assessed the available experimental values. Our calculations were carried out at the QCISD (TQ)/aug-cc-pVDZ, G2(QCI), QCISD(T)/6-311 ++G(3df,3pd) and QCISD(T)/aug-cc-pVTZ levels of theory. Geometries were optimized at both of the MP2(full)/6-31G(d) and the MP2(full)/6-31(d,p) levels, and were compared with those of the experiments if available. The MP2(full)/6-31G(d,p) tight-optimized geometries for the neutrals are closer to those of the experiments than those of the MP2 (full)/6-31G(d), and are in excellent agreement with the experimental results as shown in Table 1. In this case, we assumed that the optimized geometries for the cations would be better if p polarization functions are added to the hydrogen atoms. We firstly noted that the symmetry of the NH3+ cation was D3h, other than Cs. as reported in ref.[1]. All of the zero-point energies and the final geometries are calculated at the MP2(full)/6-31G(d,p) level of theory. We have also repeated the QCISD(T )/6-311 + G(3df,2p) calculations of ref. [1], because we could not identify their level of goemetry optimization. It is found that the total energy, -55.244 19 Hartrees, for NH2+(1A1 ) in ref.[1] might be in error. Our result is -55.336 29 Hartrees at the same level of theory. At our highest level [QCISD(T)/aug-cc-pVTZ] of calculations as shown in Table 3, the D0 (temperature at zero Kelvin) values of H2N-H, H2N+-H(3B1for NH2+ ) and H2N- H+ are 4.51, 5.49 and 8.00 eV, respectively. These data reported in re f.[1] were 4.97, 5.59 and 8.41 eV, respectively. Our result on D0(H2N-H) supports the work of ref.[2,3,5,6]. The ionization energies (IE) for NH3 and NH2 (3B1 for NH2+) at our highest level are 10.11 and 11.09 eV while in ref.[1] were 10.16 and 10.78 eV, respectively. For the latter, our result supports the experiment of ref.[3]. Our predicted D0 for HN2+-H and IE for NH2 (1A1 for each NH2+) are 6.80 and 12.39 eV, respectively. These values differ greatly from the predicted values (9.29 and 14.88 eV) of ref.[1] where the total energy of NH2+(1A1) might be in error. The D0 value for HN-H has not been found in ref.[1]. Our result supports the work of ref.[3]. We have also derived all of these values at the temperature of 298K and under the pressure of 101kPa at several levels of thoery as shown in Table 3. On examining the experiment of ref.[1] in detail, it is easy to find that all of the larger deviations might be from a too high value of the appearance potential of proton AP(H+). Indeed, ref.[1] has mentioned that the determintion of AP(H+), due to kinetic shift, would lead to a hihger value for the dissociation energy as has been pointed out by Berkowitz and Ruscic. In this work, we concluded that, besides some mistakes in the theoretical calculations of ref.[1], the dissociation energies for H2N-H and H2N-H+,the IE for NH2 (3B1 for NH2+) might also be unreliable and need to be re-examined.
     

配位化合物Zn(Met)3(NO3)2·H2O(s)(Met=L-α-蛋氨酸)的低温热容及标准摩尔生成焓

利用精密绝热热量仪测定了化合物配合物Zn(Met)₃(NO₃)₂·H₂O (s) (Met=L-α-蛋氨酸)在78-371 K温区的摩尔热容. 通过热容曲线解析, 得到了该配合物的起始脱水温度为T_D=325.10 K. 将该温区的摩尔热容实验值用最小二乘法拟合得到了摩尔热容(C_p)对约化温度(T)的多项式方程, 由此计算得到了配合物的舒平热容值和热力学函数值. 基于设计的热化学循环, 选择100 mL of 2 mol·L^-1 HCl为量热溶剂, 利用等温环境溶解-反应热量计, 得到了298.15 K配合物的标准摩尔生成焓为Δ_fH_m⁰[Zn(Met)₃(NO₃)₂·H₂O(s),s]=-(1472.65±0.76) J·mol^-1.     

C2H3自由基与O2反应的红外发射光谱及反应通道

The reaction of vinyl radicals with oxygen was investigated by Time-Resolved Fourier Transform infrared emission spectroscopy. The radicals were produced by the pulsed laser photolysis of C_2H_3Br at 248 nm. Vibrationally excited products of H_2CO(v1), HCO(v3), CO_2(v3, v), CH_3(v3), C_2H_2(v3), HO_2(v1), C_2H_2O_2(v3+v11), CO(v) formed in the C2H3+O_2 reaction have been observed. Four elementary reaction channels have been verified.