N,N′-双(2-吡啶甲酰胺)-1,4-二乙烯三胺稀土配合物的合成、表征及与DNA作用的研究

首次合成了四种N,N′-双(2-吡啶甲酰胺)-1,4-二乙烯三胺(L=C16H19N5O2)稀土配合物。经过元素分析、红外光谱、热重分析和摩尔电导值的分析,确定配合物的组成为[Ln(H3L)(NO3)2].NO3.C l3.3H2O,(Ln=La(Ⅲ),Eu(Ⅲ),Gd(Ⅲ),Ho(Ⅲ))。光谱测试结果表明:配体中两个酰胺基氧和两个吡啶氮分别与稀土离子配位,两个硝酸根均为双齿配体,稀土离子的配位数为8,Ln(Ⅲ)与H3L形成了1∶1的配合物。另外,进一步采用荧光光谱、表面增强拉曼光谱和粘度法研究了系列配合物与DNA的作用情况。研究结果表明,系列配合物与DNA之间存在相互作用,其作用模式主要为沟面结合和静电作用。     

桂皮酸邻菲罗啉稀土配合物的合成及表征

合成了 13种桂皮酸和邻菲罗啉为配体的稀土配合物RE(phen)L3(L =C6H5CH =CHCOO- )。研究了配合物的红外光谱、摩尔电导、热重 差热曲线、X射线粉末衍射及荧光光谱。结果表明 ,稀土离子与配体间形成了化学键 ,配合物为晶体化合物 ,在 4 0 0和 540℃氧化分解 ;铕配合物Eu(phen)L3发出较强荧光 ,而其它配合物则发光较弱。     

高氯酸铕、铽-二苯亚砜-1，10菲咯啉配合物的合成及荧光性质研究

同时合成了高氯酸铕、铽.二苯亚砜-1,10菲咯啉三元配合物和高氯酸铕、铽-1,10菲咯啉二元配合物。以配合物进行了元素分析,摩尔电导。确定了配合物的组成分别为:[RE(DPSO)](phen)3(ClO4)2)ClO4·nH2O(n=1,3,DPSO为二苯亚砜,phen为1,10菲咯啉)和RE(phen)4(ClO4)3。红外光谱研究表明:DP-SO以氧原子与稀土离子配位;phen以氮原子与稀土离子配位;三元配合物中ClO4-中两个与稀土离子配位,二元配合物中三个ClO4-均与稀土离子配位。对比研究了两类配合物的发光性能,溶解性能及稳定性能。研究结果表明:第二配体DPSO的加入,大大改善了配合物的发光性能,可分别使铕、铽的发光强度提高2和8倍。同时大大改善了配合物的溶解性能及稳定性能。     

新的稀土Eu,Tb(Ⅲ)β-二酮三元配合物的合成与光谱性质

采用Claisen缩合反应合成了一种β-二酮1-(4-氨基苯)-3-苯基丙烷-1,3-二酮(L:C15H13NO2),以元素分析和1H NMR谱确定了其组成,核磁和红外分析结果表明L主要以烯醇式存在。以L为第一配体,分别以邻菲罗啉(phen),2,2’-联吡啶(bipy)为第二配体,合成了新的稀土Eu,Tb(Ⅲ)三元配合物。通过元素分析、红外光谱、紫外光谱、磷光光谱和荧光光谱对合成的配合物进行了表征。荧光光谱表明:稀土铽配合物的发光性能优于稀土铕配合物,进一步研究表明配体L与Tb3+间能级差较匹配,分子内传能效率高;phen对配合物的荧光敏化效果优于bipy,表明第二配体的刚性和共轭性越大,配合物的发光性能越好。     

N, N′-二吡啶基-3-亚甲基-1, 2-乙二胺-稀土硝酸盐配合物的合成与表征

在乙腈溶液中合成了N,N′-二吡啶基-3-亚甲基-1,2-乙二胺(L)的稀土硝酸盐系列配合物.利用元素分析、 红外光谱和差热-热重分析等手段对所合成的配合物进行了表征,结果表明合成的配合物都符合稀土金属离子与配体为1∶1的化学计量比,其组成可表示为[RE(NO3)3L]·nH2O [RELa(Ⅲ),Nd(Ⅲ),Eu(Ⅲ),Tb(Ⅲ),Er(Ⅲ),n2.5,1.5,1].另外,初步研究了其中Eu(Ⅲ)和Tb(Ⅲ)配合物在室温固体状态下的荧光性质,结果显示这两个配合物表现出相应的Eu(Ⅲ)和Tb(Ⅲ)离子的特征发射.     

5-氯-2-甲氧基苯甲酸与1,10-邻菲啰啉稀土配合物的合成、表征及热分解机理

合成了三种稀土配合物[Ln(5-Cl-2-MOBA)3phen]2(Ln=Nd(1),Eu(2),Ho(3);5-Cl-2-MOBA:5-氯-2-甲氧基苯甲酸根;phen:1,10-邻菲啰啉),通过元素分析、热重-微分热重-差示扫描量热(TG-DTG-DSC)、红外光谱(IR)、紫外光谱(UV)及摩尔电导等技术对标题配合物进行了表征.荧光光谱表明配合物(2)发出铕离子的特征荧光.用热分析/傅里叶变换红外(TG-DSC/FTIR)联用技术,阐明标题配合物的热分解反应机理,并分析了逸出气体的三维(3D)红外光谱.     

Eu(BSA)3phen与PVK共混体系的光致和电致发光特性的研究

合成了一类新型的以苯甲酰水杨酸(benzoyl salicylic acid,BSA)为第一配体,邻菲罗啉(1,10-phenanthroline,phen)为第二配体的稀土配合物Eu(BSA)3phen,将导电高分子材料PVK引入到配合物中,制成了结构为ITO/PVK:RE配合物/LiF/Al的电致发光器件.通过测量电致发光和光致发光光谱,发现PVK:RE配合物混合体系存在着能量传递,并对Eu(BSA)3phen与PVK共混体系的光致发光和电致发光机制进行了分析.同时比较了几种不同PVK掺杂浓度对于器件性能的影响.     

酰胺型开链冠醚类稀土配合物的合成及其与DNA的作用研究

以2,3-二羟基萘为母体,以稀土元素为中心离子,与苦味酸盐(pic)反应合成了3个末端基不同的酰胺型开链冠醚类稀土配合物。用红外吸收光谱、元素分析、摩尔电导率、差热-热重分析等方法对配体和配合物的组成和结构进行了表征分析。通过紫外光谱、荧光光谱、黏度和循环伏安法对配合物的荧光性质及与DNA的作用方式进行了研究。结果表明:该系列配合物的组成为RE(pic)3L(L1=C26H22N2O4,L2=C30H30N2O4,L3=C28H26N2O4;RE=Eu(Ⅲ),Tb(Ⅲ),Ce(Ⅲ),Y(Ⅲ))。Eu(Ⅲ)配合物荧光强度较强,Tb(Ⅲ)配合物次之,该类配体对Eu3+的敏化效果强于对Tb3+的。配合物与DNA的作用模式均为插入式,且Eu(pic)3L3配合物与DNA的键合作用最强。     

钐、铕-2,4-二氯苯氧乙酸的二元、三元配合物的合成及荧光性能

以2,4-二氯苯氧乙酸为第一配体、1,10-菲罗啉为第二配体,合成了钐、铕的二元、三元配合物。通过元素分析、EDTA络合滴定及热重分析,确定了配合物的通式为RE(DCP)3.H2O,RE(DCP)3phen(RE=Sm,Eu;DCP=2,4-二氯苯氧乙酸根;phen=邻菲罗啉);测定了配合物红外光谱、紫外光谱、荧光光谱;研究了配合物的热稳定性。结果表明,三元配合物较二元配合物稳定;Eu(DCP)3.H2O和Eu(DCP)3phen具有荧光性能。     

3-羟基-1-金刚烷甲酸轻稀土配合物的合成、晶体结构及与DNA作用

以3-羟基-1-金刚烷甲酸(Hhata=C11H16O3),邻菲啰啉(phen)和稀土硝酸盐为原料,合成了7个轻稀土配合物(1)～(7)[RE2(hata)6(phen)2].4H2O(RE=La(1),Ce(2),Pr(3),Nd(4),Sm(5),Eu(6),Gd(7))。其中(1)为单晶样,其余6个样为粉末样;用元素分析、红外光谱、摩尔电导、热重分析等手段表征了配合物;用单晶X射线衍射法测定了(1)的晶体结构,该配合物[La2(hata)6(phen)2].4H2O(C90H114La2N4O22)属于单斜晶系,空间群P2(1)/c,a=1.33979(13)nm,b=2.6395(2)nm,c=1.31321(14)nm,β=112.174(4)°,V=4.3005(7)nm3,Z=2,Mr=1881.67,F(000)=1944.0,Dc=1.453 g.cm-3,μ(Mo Kα)=1.056 mm-1。结果表明:两个镧原子与两个邻菲啰啉中的4个氮原子和6个3-羟基-1-金刚烷甲酸根中的羧基氧原子配位,中心原子的配位数为9。用溴化乙锭荧光探针法测试了7个配合物对EB-DNA复合体系的荧光猝灭效应,实验结果显示配合物均与DNA发生了不同程度的插入作用。     

Advances of sensitive techniques in laser spectroscopy

Different techniques are used for the sensitive detection of overtone transitions of small molecules, such as H₂S, C₂H₂, OCS, O₃ in the visible and near infrared region. The techniques include: phase-modulated or wavelength-modulation absorption spectroscopy with a widely tunable single mode diode laser, opto-acoustic spectroscopy in resonance cells with a color center laser or a Ti:Sapphire laser, and sub-Doppler opto-thermal spectroscopy in cold collimated molecular beams, using a low temperature bolometer as detector. The three techniques are compared with regard to sensitivity and spectral resolution. The mass selective sensitive detection of small metal clusters Li₃ and Na₃ and their high resolution sub-Doppler spectroscopy, using resonant two-photon ionization with cw lasers, is briefly discussed.     

Decongestion of methylene spectra in biological and non-biological systems using picosecond 2DIR spectroscopy measuring electron-vibration–vibration coupling

Methylene is found in the repeat units of many polymers including proteins. In some cases it appears to be a useful reporter of variation in local environment whilst in other contexts average behaviour seems to dominate. In this paper we apply a particular 2DIR technique to a range of systems containing methylene groups, showing that mode frequencies, linewidths and splittings can be easily extracted even when the infrared absorption bands are too congested to allow reliable analysis. 2DIR spectra of polyethylene and several liquid alkanes are compared and it is shown for the case of l-arginine that the methylene scissor modes are split and that this can be resolved by tracking the 2DIR spectrum as a function of time. Calculations from first principles reveal that for most of the methylene modes studied, electrical anharmonicity is the dominant contributor to the 2DIR cross-peak intensity, with the mechanical anharmonicity making only a small contribution.     

Study of the thermal decomposition of a sepiolite by mid- and near-infrared spectroscopies

Near-infrared (NIR) and mid-infrared (MIR) spectroscopies were used to characterize the hydroxyl groups present in a sepiolite and its calcination products at 250, 500 and 800 °C. Calcining the sepiolite at 250 °C was found to result in its dehydration through the loss of coordination water. Raising the calcination temperature to 500 °C caused the sepiolite structure to fold and hydroxyl groups in octahedral layers to be removed. Finally, calcination at 800 °C resulted in a phase change leading to enstatite, as confirmed by XRD spectroscopy.     

Terahertz Time‐Domain Spectroscopy of Gases,Liquids, and Solids

The techniques and methods employed in the spectroscopic characterization of gases, liquids, and solids in the terahertz frequency range are reviewed. Terahertz time‐domain spectroscopy is applied to address a broadband frequency range between 100 GHz and 5 THz with a sub‐10 GHz frequency resolution. The unique spectral absorption features measured can be efficiently used in material identification and sensing. Possibilities and limitations of fundamental and industrial applications are discussed.     

Polarization Dependent Time-Resolved Infrared Spectroscopy and Its Applications

Polarization dependent time-resolved infrared (TRIR) spectroscopy has proven to be a useful technique to study the structural dynamics in a photochemical process. The angular information of transient species is obtainable in this measurement, which makes it a valuable technique for the investigation of electron distribution, molecular structure, and conformational dynamics. In this review, we briefly introduce the principles and applications of polarization dependent TRIR spectroscopy. We mainly focused on the following topics: (i) an overview of TRIR spectroscopy, (ii) principles of TRIR spectroscopy and its advantages compared to the other ultrafast techniques, (iii) examples that use polarization dependent TRIR spectroscopy to probe a variety of chemical and dynamical phenomena including protein conformational dynamics, excited state electron localization, and photoisomerization, (iv) the limitations and prospects of TRIR spectroscopy.     

The Kinetic and Mechanistic Evaluation of NMR Spectra. New analytical methods (18)

In addition to the static parameters of the chemical shifts and coupling constants, which serve as a source of knowledge for molecular structure and stereochemistry, an NMR spectrum can frequently furnish dynamic quantities characterizing relaxation and exchange phenomena. The information about nuclear switching processes has proved to be particularly useful in practice for the detection of internal molecular motions and for the estimation or determination of the corresponding energy barriers. A plethora of studies of this nature has in the past been performed on simple proton spectra. Methodological developments of recent years have led to a significant reduction of the effort required for the quantitative dynamic evaluation of NMR spectra arising from complex spin systems or involving other nuclei. In many cases it has, moreover, become possible to extract detailed mechanistic information inaccessible by other means. The practical execution of such analyses will be explained and illustrated by a selected number of applications.     

Isolation and Spectroscopic Characterization of New Endohedral Fullerenes in the Size Gap of C74 to C76

New alkaline earth metal endohedral fullerenes Sr@C₇₄, Sr@C₇₆‐I, II and Ca@C₇₄, prepared by means of the RF‐method, have been isolated using multistep HPLC. The purity was ascertained by anionic LDI TOF mass spectroscopy, considering the isotopic patterns of the compounds. The influence of the incorporated metal on the electronic structure has been studied by VIS‐NIR and Raman spectroscopy. Photoexcited triplet‐state EPR spectroscopy was used to investigate the structure of these otherwise EPR‐silent fullerenes. Displaying the frequency of the cage vs. encapsulated metal vibrational modes as a function of the square root of the reciprocal masses of the metals clearly separates the M³⁺@C_n^3— and the M²⁺@C_n^2— families. This seems to be a generally applicable tool for monitoring the metal to fullerene charge transfer.