Quantum-chemical study of effect of conjugation on structure and spectral properties of C105 sensitizing dye

The structure and spectral properties of two organic ruthenium complexes used as sensitizing dyes for solar batteries (well-known N3 dye and its selenophene-conjugated analogue C105 ([Ru(bpy)(bpysef)(COOH)₂(NCS)₂] (bpy = 2,2′-bipyridine, bpysef = 4,4′-bis(5-hexylselenophene-2-yl)2,2′-bipyridine)) are comparatively studied within the density functional method. It is shown that the conjugation of the bipyridine ligand with selenophene affects the electronic structure of the C105 dye. A multilevel model for interpreting the electronic spectra of dyes is proposed based on the analysis of the shapes of molecular orbitals. The nature of the absorption bands of these ruthenium complexes in the region of 300–800 nm is explained. It is found that, in the polar acetonitrile solvent, these dyes are negatively solvatochromic, which agrees with the current classical views on the effect of the solvent on the shape of electronic absorption spectra of related compounds.     

Infrared Spectra of Morfolonium (mpH)2Mo2Cl6(H20)2(I),(mpH)2Mo2ClxBr6-x(H2O)2(II)/ (mpH)2Mo2Br6(H2O)2(III) and the Pyridinium (PyH)2Mo2I6(H2O)2(IV)Hexahalo-di(aquo): dimolybdate(II) Complexes,Containing Quadruple Metal-Metal Bounds

Abstract

The electronic (800–400 nm), infrared (4000–200,400–20 cm^?1), ordinary Raman (400–200 cm^?1) spectra of morpholinium and the pyridium hexahalo-di(aquo) dimolybdate(II) complexes, containing quadruple metal-metal bonds were investigated. The electronic spectra of the solid compounds at various temperatures (25,100 and 300K) demonstrate intense and structured bands in the visible region (510–582 nm) attributed to the expected δ→δ? transitions.

From the infrared and Raman spectra, the skeletal stretching modes in these complexes have been localized, and the charectenstic bands of these ions were observed in the expected regions.

Finally, the ionic interections were relatively weak, but the existance of phenomena was perceptible and the result was obtained in agreement with X-ray data.     

双酰胺配体铕和铽混合固态配合物的光谱研究

在氯仿和乙酸乙酯溶液中合成了以1,6-二[(2’-苄胺甲酰基)苯甲氧基]己烷(L)为配体的硝酸铕和硝酸铽配合物,以及不同摩尔比的铕和铽的共沉淀配合物,又按不同的摩尔比将单一的硝酸铕和硝酸铽配合物通过研磨混合,得到混合固态的铕铽配合物。通过元素分析、红外光谱、紫外光谱、XPS 光电子能谱对配合物进行了表征,结果表明：单一稀土硝酸盐与配体形成的是2∶3型的配合物;所有的配合物都具有相似的配位结构;与单一稀土配合物相比,相同摩尔比的混合配合物的紫外吸收有所降低;混合配合物中发生了一定的化学键合作用,电子结合能有变化。通过荧光光谱对这些配合物的荧光性质进行了详细的研究, 表明与单一的铕和铽配合物相比,两种混合固态配合物无论是荧光发射峰位还是荧光强度均发生了明显变化,铽对铕的荧光强度有很强的敏化作用,铕对铽的荧光强度有猝灭作用。在紫外灯的照射下,共沉淀配合物的荧光颜色随着摩尔比的变化呈现有规律的变化。     

Phenoxide bridged tetranuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes: Syntheses,characterization and fluorescence studies

A tetranucleating compartmental Schiff base ligand system has been derived from 2,6-diformyl-4-methylphenol, p-phenylenediamine and 2-aminomethylbenzimidazole. Phenoxide bridged later first row transition metal(II) complexes of this ligand have been prepared by conventional sequential route. Ligand and complexes were characterized by routine physicochemical characterizations. The mutual influence of metal centers in terms of cooperative effect on the electronic, magnetic, electrochemical and structural properties was investigated. The Schiff-bases exhibit fluorescence originating from intraligand (π→π?) transitions. Metal mediated fluorescence enhancement is observed on complexation with Zn(II), whereas metal mediated fluorescence quenching occurs in all other complexes.     

[M(SS)(NN)](M=Zn2+,Cd2+)配合物分子内跃迁与结构的关系

报道了配合物[M(SS)(NN)](M=Zn2 ,Cd2 )(SS=mnt2-,1,2-二氰基乙烯-1,2-二硫醇离子,NN=5-NO2-phen,5-硝基-1,10-邻菲咯啉)的合成,探讨了Zn(SS)(NN)和Cd(SS)(NN)在二甲基亚砜(DM-SO)、二甲基甲酰胺(DMF)、丙酮(acetone)、吡啶(Py)等溶剂中的电子吸收光谱。研究发现配合物的紫外区的吸收带270～280nm,320～350nm,350～390nm本质上属于配体mnt2-,5-NO2-phen内部的πb→π*跃迁,可见光区400～500nm本质上属于配体mnt2-到配体5-NO2-phen的荷移跃迁(LL′CT)。确认了标题配合物的荷移跃迁光谱在相关分子轨道能级图中的对应关系。标题配合物的LL′CT吸收带与组成相似配合物M(SS)(NN)(M=Co2 ,Fe2 ,Ni2 ,Cu2 )的对应吸收带相比较弱一些,这是由于[M(SS)(NN)](M=Zn2 ,Cd2 )的LL′CT谱带(7b2→7b1)是部分解除轨道禁阻的跃迁。     

Rare Earth Complexes with 3-Carbaldehyde Chromone-(Benzoyl) Hydrazone: Synthesis,Characterization, DNA Binding Studies and Antioxidant Activity

A new ligand, 3-carbaldehyde chromone-(benzoyl) hydrazone (L), was prepared by condensation of 3-carbaldehyde chromone with benzoyl hydrazine. Its four rare earth complexes have been prepared and characterized on the basis of elemental analyses, molar conductivities, mass spectra, ¹H NMR spectra, UV-vis spectra, fluorescence studies and IR spectra. The Sm(III) complex exhibits red fluorescence under UV light and the fluorescent properties of Sm(III) complex in solid state and different solutions were investigated. In addition, the DNA binding properties of the ligand and its complexes have been investigated by electronic absorption spectroscopy, fluorescence spectra, ethidium bromide displacement experiments, iodide quenching experiments, salt effect and viscosity measurements. Experimental results suggest that all the compounds can bind to DNA via an intercalation binding mode. Furthermore, the antioxidant activities of the ligand and its complexes were determined by superoxide and hydroxyl radical scavenging methods in vitro. The rare earth complexes were found to possess potent antioxidant activities that are better than those of the ligand alone.     

Study of Infrared and Electronic Spectra Of N-Exadecyl-8-hydroxy-2-quinolinecarboxamide Complexes

The infrared and electronic spectra of twelve amphiphilic complexes of N-hexadecyl-8-hydroxy-2-quinoline carboxamide (HL) have been investigated. In IR spectra a linear relationship between the v (C-O) frequency in C-O-M bond of the complexes and the relative atomic weight of the central metal ions and a linear relationship between the v (C-O) frequency and the ionization potential of the central metal (M →M²⁺(g)+2e) were obtained. These complexes appeared to fall into two groups. One is the complexes of closed-shell metal ions such as Ca(II), Mg(II), Zn(II), Cd(II), Al(III), La(III) and Gd(III) ion, the other is the complexes of transitional metal ions such as Mn(II), Co(II), Ni(II) and Cu(II) ion. All these complexes can form stable monolayer and can be deposited as uniform LB films.     

一种新型铕的有机配合物的光物理特性及机理研究

基于吸收及荧光光谱技术对一种新型铕的有机配合物发光材料在不同状态下的光谱特性进行了表征,并分析了该配合物的光物理特性与机理。发现该配合物的吸收光谱主要是配体邻菲咯啉(phen)的贡献;随着浓度增大自短波到长波区域逐渐出现了饱和吸收现象,光谱向长波方向延伸、展宽,而且这种特征在样品的激发光谱上得到了体现;该配合物在不同状态下的荧光光谱均由Eu3+的4个特征荧光峰组成,且出现617 nm强荧光峰。提出该配合物的荧光光谱主要是在配体乙酰苯胺的微扰或介导作用下,改变了Eu3+能量场的宇称态,导致跃迁概率大大增强,并使配体phen将吸收的能量转移给Eu3+,发出617 nm强荧光峰。表明这种新型铕的有机配合物是一种有效的红光有机发光材料,具有潜在的应用价值。     

均苯三甲酸Eu-Tb配合物的合成及荧光性质研究

以H₃BTC为配体,用水热法合成了均苯三甲酸Eu-Tb系列发光配合物Eu_1-xTb_x BTC·nH₂O(H₃BTC=1,3,5-均苯三甲酸,x=0,0.1,0.3,0.5,0.7,0.9,1.0;n=0, 0.5),通过化学分析及元素分析确定了配合物的组成,用红外光谱对其进行了表征;研究了配合物的激发光谱和发射光谱,并就其荧光强度与两种稀土离子含量之间的关系进行了讨论。结果表明：(1)该系列配合物(除纯均苯三甲酸Tb外)均发出Eu离子的特征荧光,而荧光强度随着Eu和Tb离子的不同发生了明显变化,发射峰位置基本不变;(2)系列配合物中Tb对Eu的荧光强度有敏化作用,Eu对Tb的荧光强度有猝灭作用;同时Eu离子的5D₀→7F₁和5D₀→7F₂跃迁发射强度较强,且均劈裂为两个峰(587,593 nm)及(611.2,618 nm),这是由于Eu离子所处的配位环境不同所引起的。     

4-乙烯基联吡啶金属配合物的光谱研究

采用水热合成法以4-乙烯基联吡啶（dpe）为有机配体与铜,锌和镉的硫酸盐合成了三种金属有机配合物,利用红外、拉曼、紫外-可见光谱对dpe及合成的配位化合物进行了对比研究,对主要红外和拉曼谱带进行了归属,讨论了配体dpe和配合物的特征谱带与其结构间的关系。红外吸收光谱上,dpe中C—C伸缩和C—N面内弯曲的复合振动,在Cu-dpe,Zn-dpe和Cd-dpe配合物中分别位移到较高的波数处。在拉曼光谱中,对于相应的C—N,CC, C—C和C—H键的振动频率也看到了相同的变化规律。在紫外-可见光谱中,Zn-dpe,Cd-dpe分别只有一个配体本身的跃迁吸收峰,而配合物Cu-dpe由于发生了d—d电子跃迁,产生两个吸收峰,分别归属为配体本身的跃迁吸收谱带和配位体场吸收谱带,可见同一种配体与不同的金属离子合成的配位化合物,由于金属离子核外电子分布的不同,其紫外-可见光谱有很大变化。     

Cu^2＋—柞蚕丝蛋白络合物的ESR研究

本文用ESR、UV和IR研究了Cu~(2 )-柞蚕丝蛋白络合物,确定了铜的价态及其配位体,给出了化学结构模型,用实验参数计算了配位键参量和配位场能.     

红色荧光联苯四甲酸碱式稀土配合物的合成及发光性能

以3,3',4,4'-联苯四甲酸二酐(BPDA)为配体原料合成了两种碱式铕和铽配合物,通过元素分析、红外光谱和热重分析等测试技术表征了配合物的结构组成,用紫外光谱和荧光光谱研究了配合物的发光性能。结果表明:两种配合物的组成分别为Tb₅L₃(OH)₃·8H₂O和Eu₅L₃(OH)₃·10H₂O(L=BPDA),稀土铕(Ⅲ)和铽(Ⅲ)与羧酸根的配位方式主要以桥式配位为主,兼有少量螯合配位。这些配合物的热稳定性能良好。铽配合物和铕配合物均呈现红色荧光,铽配合物归属于⁵D₄→⁷F₃跃迁(613 nm)的荧光寿命为491.11 μs,归属于⁵D₄→⁷F₅ 跃迁(544 nm) 的荧光寿命为27.9 μs;铕配合物归属于⁵D₀→⁷F₂ 跃迁 (613 nm) 的荧光寿命为329.5 μs,荧光量子产率为13.05%。     

2, 6-双(2-苯并咪唑)吡啶-乙酸锌的合成和光谱性能

合成了一种新型的蓝光发射材料2,6-双(2-苯并咪唑)吡啶-乙酸锌,并利用元素分析、红外光谱、UV-Vis吸收谱、荧光激发光谱和荧光发射光谱研究了其结构、光学特性、能级结构和发光机理。结果表明,2,6-双(2-苯并咪唑)吡啶-乙酸锌是一种三齿配体的发光材料。在N,N-二甲基甲酰胺(DMF)溶液体系中测定了材料的紫外吸收光谱,2,6-双(2-苯并咪唑)吡啶的吸收峰波长主要为330,344nm;2,6-双(2-苯并咪唑)吡啶-乙酸锌的吸收峰波长主要为346,366nm。禁带宽度为3.01eV,在紫外光激发下,在DMF溶液体系中的荧光发射峰在458nm处,固态荧光发射峰在475nm,均为蓝色荧光,色纯度高,荧光量子效率高,其荧光发射主要来源于长波吸收带,最大波长吸收带对荧光发射贡献最大。有望通过合理的设计运用到有机电致发光器件中去。     

掺杂金属离子对(Eu,Tb)稀土配合物发光性质的影响

合成了以柠檬酸为第一配体、1,10-菲咯啉为第二配体的单核稀土(Eu、Tb)配合物和Tb/Y、Eu/Y按不同比例混合的掺杂稀土配合物。采用红外光谱、紫外光谱、激发和发射光谱等对合成的配合物结构和荧光性能进行了表征。红外光谱表明稀土离子与第一、第二配体进行了配位,配合物的紫外吸收主要是配体的吸收,保持了π→π^* 电子跃迁的特征。激发和发射光谱表明,不发光稀土离子Y³⁺的掺入能显著增强发光稀土离子的光发射强度。     

2-硫醇基甲基苯并咪唑锌制备及其光谱分析

采用一步法制备出2-硫醇基甲基苯并咪唑锌(MMBZ),通过FTIR,UV-Vis,XRD,TG-DSC对其进行检测和表征,揭示出MMBZ的微观结构和内在规律性。FTIR揭示了MMBZ分子内部的各元素之间的化学键键型,确定最终产物为MMBZ。UV-Vis检测出MMBZ在219.6,245.5和302.2 nm有三个吸收峰,分别为MMBZ分子中S—C、苯环、含N五元杂环的n→σ*,π→π*,π→π*的电子跃迁产生的,为企业MMBZ产品质量检测,推测MMBZ的结构提供实验依据。XRD谱图发现MMB作为MMBZ的配体,仍然保留其单元基本结构,MMBZ分子呈非晶态结构。TG-TG-DSC检测出MMBZ的质量变化与热效应两种信息,在167.5,155.3,253.7,324.8,391.3 ℃吸热峰,分别为杂质溶剂分解峰、相变峰、分解峰。一步法制备环保复合型橡胶防老剂MMBZ,方案切实可行,本研究通过检测结果推测MMBZ结构,关联MMBZ的性能,探究其防橡胶老化机理,开拓MMBZ应用范围,提供基础实验数据。     

Co,Mn,Ni的联苯酸配合物的合成及光谱研究

合成了联苯酸 ,并以其和吡啶为配体 ,制备了第一过渡系金属离子Co(Ⅱ ) ,Mn(Ⅱ ) ,Ni(Ⅱ )的 3种配合物 ,并通过元素分析、IR及UV等手段对配合物进行了表征 ,推测了可能的组成和结构。     

Spectral Study of Some Samarium Complexes in the Region 750–250 cm−1

Abstract

Rare earth β -diketonates and diketo-ester complexes are promising laser materials due to narrow line width of the internal 4fⁿ transitions and weak crystal-field interactions¹. The electronic energy states², spectral intensities^3–5, bonding^6,7 and infrared spectra^8–11 of some of these complexes have been recently reported by the authors. However, little information regarding their structure and strengths of various bonds are available. The infrared spectra of rare earth complexes in the spectral region 4000 – 750 cm^?1 are characteristic of the ligand, while those in the region 750 – 250 cm^?1 characterize the metal-ligand bonding. The present communication reports the values of force constants computed from the observed infrared absorption spectra of four ethyl 1-methyl acetoacetate (EMA) and ethylbenzoylacetate (EBA) complexes of trivalent samarium in the region 750 – 250 cm^?1.     

Synthesis,Spectroscopic and Antimicrobial Investigations of Scandium(Ⅲ) Complexes with Four Kinds of Sulfa Drugs

Herein,this article was focused on the synthesis and discussed the spectroscopic characterizations of four new scandium(Ⅲ)sulfa-drug complexes.The nomenclature and symbols of these drugs were sulfadimidine(sulp-1),sulfanilamide(sulp-2),sulfamethoxazole(sulp-3)and sulfadiazine(sulp-4).The microanalytical and spectroscopic analyses which utilized in this study were micro-analyses,magnetic,FT-IR,UV-Vis techniques.The mid infrared spectra deduced that the four sulfa-drug chelates acts as a bidentate chelates with scandium(Ⅲ)ion via two nitrogen atoms of-NH2-Ar and-NH-SO2 groups.Also,the FTIR spectra of Sc3+complexes referred to the existed of new medium weak bands in the range of 500~400 cm^-1 due to stretching vibration bands ofν(M-N).The elemental analysis technique confirmed the 1∶2 stoichiometry between Sc3+ions and sulp ligand with molecular formula[Sc(sulp)2(Cl)2]·Cl.At room temperature,the results of magnetic measurements for the Sc(Ⅲ)complexes indicated that all of the synthesized complexes have a diamagnetic character with octahedral configuration.The electronic spectra of the free sulfa-drug ligands shows band at 275 and 310 nm which are intraligand charge transfer band.The electronic sbsorption spectra of the Sc3+complexes were recorded using DMSO solvent.The spectra of complexes display bands within 275~388 nm,which attributed toπ-π*,n-π*and charge-transfer M-LCT electronic transitions,which strongly favors the octahedral geometry around Sc(Ⅲ)metal ions.1HNMR spectra of complexes referred to the downfield proton shifts of the-NH2 and NHSO2 groups,which supported the place of coordination.The half maximal inhibitory concentration(IC50)of the ScⅢcomplexes was assessed against the human hepato cellular carcinoma(HepG-2)tumor cell line.     

铽与两种不同结构羧酸配合物的低温固相合成及发光性质研究

以两种不同结构的羧酸苯乙酸和苯基羟基乙酸与氯化铽为原料,采用低温固相反应合成了两种羧酸铽配合物。经元素分析、稀土络合滴定、摩尔电导确定了配合物的组成为： Tb(L₁)₃·H₂O,Tb(L₂)₃·4H₂O(L₁= C₆H₅ CH COO- ,L₂=C₆H₅CH(OH)COO-)。测定了配体及配合物的IR谱、1H NMR及配体的磷光光谱和铽配合物荧光激发和发射光谱。根据磷光发射光谱数据计算了配体的三重态能级值。比较两个配合物的荧光发射主峰5D₄→7F₅强度： 苯基羟基乙酸铽为苯乙酸铽的5倍。由此可见在配体亚甲基上引入拉电子基团羟基,将会扩大共轭体系π电子的离域范围,提高能量传递效率,提高稀土离子的发光强度。