Experimental and Theoretical Study of the Electronic States and Spectra of TeH and TeLi

Gas-phase emission spectra of the hitherto unknown free radical TeLi have been measured in the NIR range with a Fourier-transform spectrometer. The emissions were observed from a fast flow system in which tellurium vapor in argon carrier gas was passed through a microwave discharge and mixed with lithium vapor in an observation tube. Two systems of blue-degraded bands were measured at high spectral resolution in the ranges 8000-9000 and 5700-6700 cm(-1) and vibrational and rotational analyses were performed. In order to aid in the analysis of the experimental data, a series of relativistic configuration interaction calculations has been carried out to obtain potential curves for the low-lying states of TeLi and the isovalent TeH and also electric dipole transition moments connecting them. As in the TeH system, the ground state of TeLi is found to be X(2)Pi(i), but with a remarkably smaller spin-orbit splitting. The TeLi calculations indicate a strongly bound A(2)Sigma(+) state, while in TeH the analogous state is computed to lie significantly higher at approximately 32 000 cm(-1), and it is strongly predissociated. Based on the theoretical analysis, the observed TeLi band systems are assigned to the transitions A(2)Sigma(+)(A1/2)-->X(1)(2)Pi(3/2)(X(1)3/2) and A(2)Sigma(+)(A1/2)-->X(2)(2)Pi(1/2)(X(2)1/2). Analysis of the spectra has yielded the molecular constants (in cm(-1)) X(1)(2)Pi(3/2):omega(e)=457.49(3), omega(e)x(e)=2.482(9), B(0)=0.408908(8); X(2)(2)Pi(1/2): T(e)=2353.44(3), omega(e)=456.28(4), omega(e)x(e)=2.635(8), B(0)=0.414954(8), p(0)=1.00637(4); A(2)Sigma(+): T(e)=8574.64(2), omega(e)=437.81(3), omega(e)x(e)=2.581(8), B(0)=0.423903(8), p(0)=-0.19915(2), where the numbers in parentheses are the standard deviations of the parameters. Comparison of the isovalent TeLi and TeH systems emphasizes that the difference in bonding character (ionic in TeLi vs covalent in TeH) is responsible for qualitative differences in the electronic spectra of these two molecules. Copyright 2001 Academic Press.     

铕、铽四元配合物的合成及其发光性能

以对苯二甲酸(p-PA)、苯甲酸(BA)、邻(间、对)甲基苯甲酸[o(m、p)-MBA]和1,10-邻菲啰啉(phen)为配体,合成了4种Eu(Ⅲ)和4种Tb(Ⅲ)的四元配合物。通过EDTA配位滴定分析和元素分析,确定了各配合物的组成。利用红外光谱分析对配合物的结构进行了初步表征,在配合物中羧基氧原子和1,10-邻菲啰啉中的氮原子均参与了配位。在室温条件下,测定了各固体配合物的激发和发射光谱,结果表明:4种铕的四元配合物中,苯甲酸配合物在614 nm最强发射峰的荧光强度强于3种甲基取代苯甲酸配合物的荧光强度;4种铽的四元配合物中,以对甲基苯甲酸为配体的配合物在545 nm最佳发射峰和490 nm次强发射峰的荧光强度较高。     

金属-糖胺配合物的合成,光谱表征及催化酯类水解的动力学研究

合成了4种新的糖胺 金属配合物,分别为[Ni(HL) (H2 O) 2 ]2 Cl2 ·CH3OH·2H2 O ,[Cu(HL) ]2 Cl2 ·CH3CH2 OH·3H2 O ,[Zn(HL) ]2 Cl2 ·H2 O ,[Co(HL) (H2 O) (OH) ]2 Cl2 ·CH3OH·2H2 O (HLN ,N′ 二βD 葡萄糖基乙二胺) ,并用元素分析、红外、紫外、核磁共振氢谱对其结构进行了表征。结果表明,Ni(Ⅱ) ,Co(Ⅲ)配合物为八面体构型,而Cu(Ⅱ) ,Zn(Ⅱ)配合物为四面体构型。最后研究了其对对硝基苯吡啶甲酸酯(PNPP)催化水解的催化速率常数。     

The Millimeter- and Submillimeter-Wave Spectrum and the Dipole Moment of Ethylenimine

The 0(0)(0) bands of the ?(2)B(2)-&Xtilde;(2)A(1) and &Btilde;(2)B(1)-&Xtilde;(2)A(1) systems of SrNH(2) were observed at Doppler-limited resolution using a Broida oven source and laser-induced fluorescence detection. A full rotational analysis of both transitions was performed including K(a) levels up to 5 and J levels up to 55. The &Btilde;(2)B(1) state was found to be extensively perturbed and only some of the subbands could be analyzed. The ?(2)B(2) and &Btilde;(2)B(1) states undergo a strong Coriolis-type interaction which results in extremely large spin-rotation splittings in both states, effectively splitting all levels with K(a)(') not equal 0 into two well-separated spin components. Copyright 2000 Academic Press.     

纳米固体超强酸的制备及表征

本文采用不同的金属离子(Sn2+,Sn4+,Al3+,Ag+,Ni2+)和SO2-4浸渍ZrO(OH)2的方法制备了一系列金属改性的SO2-4/ZrO2的纳米固体超强酸。并通过指示剂法测定其酸强度,用IR、BET、XRD、TEM及化学分析等多种试验手段对催化剂进行表征,并通过正己烷裂解反应考察了该类固体超强酸催化剂的催化活性。结果发现:不同的金属离子掺杂制得的改性SO2-4/ZrO2催化剂具有不同的性能。Sn2+、Sn4+和Al3+掺杂的超强酸有较强的酸性,但只有Ni2+、Sn2+掺杂的SO2-4/ZrO2样品具有正己烷裂解反应活性,Ag+、Sn4+掺杂改性的SO2-4/ZrO2样品不具有正己烷裂解活性。     

Photoexcitation of K-shell and L-shell hollow beryllium

We have observed K-shell and L-shell hollow beryllium atoms (2s(2)2p3s and 1s3s(2)3p) created by photoexcitation using synchrotron radiation. Resonance shapes were fitted to the Fano profile and the parameters were deduced. A Dirac-Fock calculation was performed to identify the configuration of the peaks and to predict other hollow atomic peaks. The results of the calculation were in good agreement with the experimental data. The comparison of the transition strength has revealed that the three-electron photoexcitation to the 1s3s(2)3p configuration is stronger than the two-electron photoexcitation to the 2s(2)2p3s configuration. This is attributed to the large overlap between the 2s orbital of the ground state (1s(2)2s(2)) with the orbital of the L-shell hollow state (1s3s(2)3p).     

PdH、PdH2分子的结构与势能函数

用相对论有效原子实势(SDD)和密度泛函(B3LYP)方法对PdH和PdH2体系的结构进行了优化,计算表明:PdH分子的几何构型为C∞v,其基态为X2∑+态,键长R=0.154 11 nm,离解能为De=2.511 0eV,谐振频率ωe=2 156.226 9 cm-1,并拟合得到Murrell-Sorbie势能函数;PdH2分子稳态为C2y构型,电子组态为1A1,平衡核间距RPdH=0.151 73 nm,键角∠HPdH=72.373 3°,基态简正振动频率:对称伸缩振动频率v1(b2)=2 104.369 6 cm-1、弯曲振动频率v2(a1)=528.742 6 cm-1、反对称伸缩振动频率v3(a1)=2 208.649 0 cm-1,离解能De=5.318 56 eV.在此基础上,用Murrell-Sorbie函数和多体展式理论导出PdH(C∞v,X2∑+)、PdH2(C2v,1A1)分子的解析势能函数.其等值势能面图准确地再现了PdH2分子的结构特征和离解能,由此讨论了Pd+H2分子反应的势能面静态特征.     

Static and Ultrafast Transient Photophysics of Mono- and Dual-Branched Triarylamines

Mono- and dual-branched molecules, { 4-[2-（4-benzothiazol-2-yl-phenyl）-vinyl]-phenyl}-（4-methoxy-phenyl）-phenyl- amine （BS1） and bis-{4-[2- （4-benzothiazol-2-yl-phenyl）-vinyI]-phenyl}-（4-methoxy-phenyI）-phenyl-amine （BS2）, are investigated with one- and two-photon static spectroscopy, and the femtosecond fluorescence up-conversion technique. The molecules show branch-based fluorescence emission at low quantum yield. U1trafast non-radiative decay on a picosecond time scale is found and is attributed to intramolecular charge-transfer bridged by the central triphenylamine. The two-photon absorption cross-sections of BS1 and BS2 are 19.1 and 19.4 GM, respectively.     

Tautomery and acid-base properties of some azoderivatives of benzoylacetone

The structural, tautomeric and acid-base properties of the new 1-phenyl-2-(2-hydroxy-3-sulfo-5-chlorophenylhydrazo)butane-1,3-dione (H₂L¹), 1-phenyl-2-(2-hydroxy-3,5-disulfophenylhydrazo)butane-1,3-dione (H₂L²), 1-phenyl-2-(2-hydroxy-3-sulfo-5-nitrophenylhydrazo)butane-1,3-dione (H₂L³) and 1-phenyl-2-(2-hydroxy-4-nitrophenylhydrazo)butane-1,3-dione (H₂L⁴) were studied using IR, ¹H and ¹³C NMR spectroscopies and potentiometry. The study reveals that H₂L^1-4 and the known 1-phenyl-2-(2-hydroxyphenylhydrazo)butane-1,3-dione (H₂L⁵) exist in solution as a mixture of Z-enol-azo-II and hydrazo-III tautomeric forms and that an increase in the solvent polarity shifts the tautomeric balance to the enol-azo form. The thermodynamic parameters of the proton dissociation in H₂L^1-5 were determined showing that this process is unspontaneous, endothermic and entropically unfavorable.     

Synthesis and Characterization of Molecules Containing Thiazole and Oxazole Moieties and Study of ESIPT Phenomenon

Two novel ESIPT molecules, 2-[4-(1,3-benzothiazol-2-yl)naphtho[1,2-d][1,3]oxazol-2-yl]phenol 9a and 4-[4-(1,3-benzothiazol-2-yl)naphtho[1,2-d][1,3]oxazol-2-yl]benzene-1,3-diol 9b were synthesized by condensing 1-amino-3-(1,3-benzothiazol-2-yl)naphthalen-2-ol with 2-hydroxybenzoic acid and 2,4-dihydroxybenzoic acid respectively. The novel compounds were characterized by FT-IR, (1)H NMR, Mass spectral and elemental analysis. Effect of polarity on photo physical properties, absorption and emission were studied. Compounds showed single absorption and dual emission due to ESIPT phenomenon. The structural changes due to ESIPT phenomenon in terms of bond angle, bond distances and geometry were investigated by using Gaussian 03 software. These two novel ESIPT molecules are thermally stable up to 200?°C.     

The periodic table of urea derivative: small molecules of zinc(II) and nickel(II) of diverse antimicrobial and antiproliferative applications

Molecular Diversity - Two complexes of Zn(II) and Ni(II) ions with the urea derivative, 2-benzimidazolyl-urea (BZIMU), of formulae [ZnBZIMU)2(H2O)](NO3)2 (1) and [Ni(BZIMU)2(CH3CH2OH)2](NO3)2 (2)...     

从头计算对GanNm团簇的结构与稳定性的研究

用B3LYP-DFT方法对GanN2(n=1~7)和GanN(n=2~8)团簇的结构与稳定性进行了研究.在6-31G*水平上进行了结构优化和频率分析,得到了GanN2(n=1~7)和GanN(n=2~8)团簇的基态结构.在GanN(n=2~8)团簇的基态几何结构中,N原子处在分子结构的中心;在GanN2(n=1~3)团簇中,N—N键比Ga—N键强;在GanN2(n=4~7)团簇中存在Ga3N单元和Ga4N单元.在GanN2(n=1~7)和GanN(n=2~8)团簇中,Ga4N2,Ga6P2,Ga3N,Ga5N和Ga7N较其它团簇稳定.     

Theoretical calculation of energy levels and radiative lifetimes of Tl I

Considering the perturbation, the results of theoretical calculation of five Rydberg series energy levels 6s2ns^2S1/2 （n = 7 - 20）, 6s^2nd^2D3/2 （n = 6 - 20）, 6s^2nd^2D5/2 （n = 6 - 20）, 6s^2np^2P1/2^0 （n = 7- 20）, and 6s^2np^2P3/2^0 （n = 7-20） for Tl I are presented using the weakest bound electron potential model （WBEPM） theory. Furthermore, the radiative lifetimes of this five series are also calculated. The calculated values of energy levels and lifetimes are in good agreement with the experimental results.     

甲基乙基亚硫酸与亚氨基负离子多组分反应及机理的理论研究

采用分子动力学方法研究了一系列同比例(5:5,10:10,20:20,50:50)和不同比例(20:30,20:40,20:50和30:20,40:20,50:20)的亚氨基负离子与甲基乙基亚硫酸的反应显示,有较多的亚氨基转化为氨气,同时甲基乙基亚硫酸分解为甲醇、乙醇和一些小的碳化合物等物质.通过密度泛函的B3lyp和Bhandhlyp两种方法,在6-311++G(3df, 3pd)水平下对其反应机理进行研究表明,此反应为多通道多步骤的反应体系,无论主反应还是次反应均为放热反应,其中生成产物为P1(CH₃OSO₂~-+NH₃+C₂H₄),P2(CH₃OSO₂~-+NH₂CH₂CH₃),P3(CH₂O+SO₂+NH₃+C₂H₅~-)的路径为最佳反应通道,而生成P4...     

金属羰基化合物（CpFe（CO）2）2与金属氧化物表面作用的傅里叶变…

用漫反射红外光谱和光声红外光谱研究了金属羰基化合物（ＣｐＦｅ（ＣＯ）２）２Ｃｐ＝η＾５－Ｃ５Ｈ５与酸性，中性和碱性Ａｌ２Ｏ３及ＴｉＯ２的相互作用，结果表明，在Ａｌ２Ｏ３表面生成的洗生物种类及浓度与Ａｌ２Ｏ３的酸碱度明显相关，在酸性Ａｌ２Ｏ３表面，主要存在衍生物（ＣｐＦｅ（ＣＯ）２Ｆｅ－Ｈ－Ｆｅ（ＣＯ２Ｃｐ）＾＋及少量的ＣｐＦｅ（ＣＯ）２（－Ｏ－）；在中性Ａｌ２Ｏ３表面存在的ＣｐＦｅ（ＣＯ）２（－Ｏ     

Ratiometric comparison of intense field ionization of atoms and diatomic molecules

Intense-laser ionization rates for rare gas atoms and diatomic molecules have been precisely compared by making simultaneous measurements of ionization yield vs laser intensity for mixed atomic and molecular targets. At a given laser intensity, the N (2) and F (2) ionization yields are slightly greater than that of Ar. Conversely, comparison of O (2) and S (2) with Xe indicates significant ionization suppression in these molecules. Recent molecular ionization models that successfully describe ionization suppression in O (2) and its absence in N (2) fail to explain our observations in F (2) and S (2).     

冠醚铕镧异核配合物的合成表征及荧光性质

以 18冠 6为配体 ,分别与高氯酸铕和高氯酸镧在乙腈介质中反应 ,合成冠醚铕和冠醚镧配合物 ;两种冠醚配合物与交联配体———对苯二甲酸反应 ,形成了对苯二甲酸冠醚铕镧异核稀土超分子配合物。由元素分析数据推测 ,超分子配合物的组成式为EuLaL2 L′(ClO4) 4 ·6H2 　 [L =18 C 6 ,L′ =p C6H4(COO-) 2 ],测定了超分子配合物的红外光谱 ,紫外光谱 ,摩尔电导及荧光光谱。结果表明 ,冠醚和对苯二甲酸根与稀土离子配位 ,而高氯酸根离子处于配合物的外界 ,铕镧异核稀土超分子配合物的荧光强度是冠醚铕的 8倍多。     

Sonocatalytic degradation of methyl orange in the presence of TiO2 catalysts and catalytic activity comparison of rutile and anatase

Rutile and anatase titanium dioxide (TiO(2)) powders were used as sonocatalysts for the degradation of methyl orange which was used as a model compound. Ultrasound was used as an irradiation source. It was found that the sonocatalytic degradation ratios of methyl orange in the presence of TiO(2) powder were much better than ones without any TiO(2), but the sonocatalytic activity of rutile TiO(2) particles was obviously higher than that of anatase TiO(2) particles. Although there are many factors influencing sonocatalytic degradation of methyl orange, the experimental results show that the best degradation ratio of methyl orange can be obtained when the experimental conditions of the initial methyl orange concentration of 10 mg/l, rutile TiO(2) added amount of 500 mg/l, ultrasonic frequency of 40 kHz, output power of 50 W, pH=3.0 and 40 degrees C within 150 min were adopted. In addition, the catalytic activity of reused rutile TiO(2) catalyst was also studied and found to be better than new rutile TiO(2) catalyst sometimes. All experimental results indicated that the method of the sonocatalytic degradation of organic pollutants in the presence of TiO(2) powder was an advisable choice for treating non- or low-transparent organic wastewaters.     

LB膜的XPS光谱及其电致发光

采用X射线光电子能谱 (XPS)和UV Vis光谱研究了 2个以 8 氨基喹啉为亲水头基的两亲配体 ;2 长链烷基丙二酸二 (8 氨基喹啉 )酰胺 (H2 A) (H2 A1 2 :长链烷基为十二烷基 ;H2 A1 6 :十六烷基 )在气 /水界面与Cu2 离子的配位作用。配位后H2 A1 2 和H2 A1 6 单分子膜的崩溃压分别由 12 5和 15 6mN·m- 1 增加至 2 8 0和33 8mN·m- 1 。从含Cu2 离子亚相表面组装的LB膜出现了Cu2 离子的特征XPS峰 ,Cu2p为 935和 95 5eV ,XPS表明H2 A与Cu2 的配位比为 1∶1。H2 A的LB膜可以用作电致发光 (EL)器件的空穴传输材料 ,三层EL器件ITO/TPD/LB膜 /Alq3/Al(LB膜分别为 15层H2 A1 2 和 15层H2 A1 6 )的驱动电压分别为 6 5和 7 5V ,最大亮度分别为 6 2 1和 2 0 1cd·m- 2 。     

三价铕荧光络合物与聚乙烯吡咯烷酮复合物研究

为研究稀土荧光络合物与高分子形成的复合物的结构与发光性能间的关系,利用α-噻吩甲酰三氟丙酮（TTA）和三苯基氧化膦（TPPO）与氯化铕（EuCl₃）分别制备了Eu(TTA)₃·2H₂O和Eu(TTA)₃·(TPPO)₂络合物,及其与聚乙烯吡咯烷酮（PVP）的复合物。采用荧光光谱,红外光谱和透射电镜等方法对复合物进行了表征。荧光光谱测定结果表明Eu(TTA)₃·2H₂O与PVP K30结构单元摩尔比为1∶35的PVP/Eu(TTA)₃·2H₂O复合物的612　nm发射峰的荧光强度较Eu(TTA)₃·2H₂O络合物有显著提高。红外光谱研究表明络合物的Eu3+与PVP分子的羰基之间存在着明显的配位作用,并且存在多种配位方式。透射电镜观察结果表明复合物具有微相分离结构,其中的稀土络合物为无定形结构,这进一步表明PVP与络合物分子间存在相互作用。