两种Zn(Ⅱ)配合物电子结构和光谱性质的理论研究

为了探究Zn(Ⅱ)配合物Zn(ATSM)(A)和Zn(BTSC)(DMSO)(B)的电子结构和光谱性质,采用M06方法优化了它们的基态几何构型,并利用计算得到的电子结构信息绘制了配合物在吸收过程中的电子云分布图.理论模拟出的吸收光谱数据与实验结果吻合较好.而且,在理论上检测到了实验上没有报道到的吸收峰.     

三种席夫碱-Ni(Ⅱ)配合物的电子结构和吸收光谱的理论计算

采用B3LYP/6-31+G(d)-LANL2DZ方法优化了三种Ni(Ⅱ)的席夫碱配合物基态的几何构型,并在相同水平下进行了频率分析以确认稳定点的性质;利用含时密度泛函理论和极化连续介质模型(PCM),按TDB3LYP/6-31+G(d)-LANL2DZ水平计算了目标配合物在N,N-二甲基甲酰胺溶剂中的电子结构和吸收光谱.计算结果表明,配体中间位甲氧基的存在使配合物A具有较大的HOMO-LUMO能级差;且三种Ni(Ⅱ)配合物的S0→S1态的跃迁能按照A→B→C的顺序依次降低.     

用密度泛函理论研究两种金属镍席夫碱配合物的电子结构和光谱性质

采用密度泛函理论(DFT),在B3LYP/6-31+G(d)-LANL2DZ水平上,研究了两种Ni(II)的席夫碱配合物1和2基态的几何结构,并在相同水平上进行了频率分析以确认稳定点的性质.基于优化的几何构型,在TDB3LYP/6-31+G(d)-LANL2DZ水平上,采用极化连续介质模型(PCM)在N,N-二甲基甲酰胺溶液中计算了配合物1和2的电子结构和紫外吸收光谱.结果显示,当配体对位上的Br原子被-NO2取代时,配合物的HOMO-LUMO能级差增大,从而导致配合物2的最大吸收波长相对于配合物1的发生蓝移.     

4-(二乙氨基)水杨醛缩4-氨基安替比林席夫碱的合成及荧光性质

合成了4-(二乙氨基)水杨醛缩4-氨基安替比林席夫碱,通过红外光谱、核磁共振谱、元素分析等对其结构进行了表征。利用分子荧光仪对其与Zn²⁺、Ni²⁺、Co²⁺、Pb²⁺、Cd²⁺、La³⁺、Ce³⁺、Sr²⁺、Ag⁺、Ru³⁺等金属离子作用前后的荧光性质进行了检测。检测结果表明,加入不同的金属离子后,该希夫碱的荧光发射波长略有变化,但荧光强度发生了不同程度的改变,其中Ru³⁺与希夫碱作用后的荧光强度显著增强。     

腙基席夫碱配体铜(Ⅱ)配合物的合成、结构表征、生物活性和密度泛函理论计算

以甲醇为介质,合成了3种新的席夫碱配体HL¹(2-hydroxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone)、HL²(4-hydroxybenzaldehyde2 -(2 - oxo- 1,2 -diphenylethylidene)hydrazone)和 L³(2 -methoxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone)的Cu(Ⅱ)配合物1~3。通过元素分析、光谱方法、磁化率测量和密度泛函理论(DFT)计算对配合物进行了表征。通过单晶X射线衍射研究对合成的配体进行了结构表征。通过DFT计算确定了配合物的优化结构。通过紫外可见吸收光谱和荧光发射光谱研究了配合物与小牛胸腺DNA(CT-DNA)的结合能力。吸收光谱研究揭示了增色效应,并提出了与CT-DNA相互作用的可能模式。溴化乙锭(EB)竞争结合研究表明,配合物可以取代 DNA-EB 加合物中的 DNA,且配合物可能以嵌入模式与 CT-DNA结合。配合物对革兰氏阴性肺炎克雷伯菌、大肠杆菌、鲍氏志贺菌和革兰氏阳性金黄色葡萄球菌的体外抗菌活性研究表明,配合物2对肺炎克雷伯菌和鲍氏志贺菌具有明显抗菌活性,但配合物1和3没有表现出任何显著的抗菌活性。     

腙基席夫碱配体铜(Ⅱ)配合物的合成、结构表征、生物活性和密度泛函理论计算

以甲醇为介质,合成了3种新的席夫碱配体HL¹(2-hydroxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone)、HL²(4-hydroxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone)和 L³(2-methoxybenzaldehyde2-(2-oxo- 1,2-diphenylethylidene)hydrazone)的Cu(Ⅱ)配合物1~3。通过元素分析、光谱方法、磁化率测量和密度泛函理论(DFT)计算对配合物进行了表征。通过单晶X射线衍射研究对合成的配体进行了结构表征。通过DFT计算确定了配合物的优化结构。通过紫外可见吸收光谱和荧光发射光谱研究了配合物与小牛胸腺DNA(CT-DNA)的结合能力。吸收光谱研究揭示了增色效应,并提出了与CT-DNA相互作用的可能模式。溴化乙锭(EB)竞争结合研究表明,配合物可以取代 DNA-EB 加合物中的 DNA,且配合物可能以嵌入模式与 CT-DNA结合。配合物对革兰氏阴性肺炎克雷伯菌、大肠杆菌、鲍氏志贺菌和革兰氏阳性金黄色葡萄球菌的体外抗菌活性研究表明,配合物2对肺炎克雷伯菌和鲍氏志贺菌具有明显抗菌活性,但配合物1和3没有表现出任何显著的抗菌活性。     

配合物[N,N'-二(亚水杨基)-1,2-乙二胺]Pt(Ⅱ)光谱性质的理论研究

化合物[N,N'-二(亚水杨基)-1,2-乙二胺]Pt(Ⅱ)(1)在OLED材料上具有很大的应用潜力, 我们利用密度泛函(DFT/Lanl2dz)方法计算了它的电子结构和光谱性质. 计算结果与实验值符合得很好. 计算结果表明, 该化合物最低能吸收和三态磷光发射均来自于[L(Phenoxide lone pair)→π*(imine)](LLCT: ligand-to-ligand charge transfer)和[Pt(5d)→π*(Schiff base)](MLCT: metal-to-ligand charge transfer)的混合电荷跃迁. 另外, 计算得到了该配合物在气态中的激发态几何结构. 通过在不同的溶液中计算吸收和发射光谱, 发现该化合物没有明显的溶剂化显色效应, 说明溶液极性对光谱的影响不大.     

含有共轭炔基的发光Pt(Ⅱ)配合物发光性质的密度泛函理论研究

本文利用密度泛函(DFT)和含时密度泛函(TDDFT)方法研究了一系列配合物Pt(ppy)(C≡C)_nPh(ppy=6-phenyl-2,2′-bipyridine n=1～6)的基态和激发态的电子结构和发射光谱。计算揭示,当(C≡C)_n链长n=1～3时,配合物1～3的磷光发射被指认为是 ³[π^*(ppy) → Pt(5d),π((C≡C)_nPh)](³LMCT/³LLCT)的混合电荷跃迁。而当n=4～6时,配合物4～6的磷光发射主要是来自于(C≡C)_nPh配体内部³ππ^*跃迁(³ILCT)和少部分的³LLCT微扰跃迁。通过分析前线轨道成份,可以预测当炔基链长n趋于∞时,电荷跃迁将完全发生在炔基链的π轨道之间。     

席夫碱锰(Ⅱ)配合物的合成及结构表征

由乙酰丙酮和1R,2R-环己二胺缩合得到N,N’-双(乙酰丙酮)-1R,2R-环己二胺的席夫碱配体L,然后与MnCl2.4H2O进行配位反应,得到了配合物[Mn(L)Cl2]n.nH2O,并用元素分析、FT-IR和X-射线单晶衍射进行了表征。结果表明,配合物属于单斜晶系,空间群P21,晶体学参数:a=9.2719(14),b=18.871(3),c=24.767(4),β=98.346(4),Z=2,Dc=0.854g.cm-3,F(000)=1164,R1=0.1201,wR2=0.2968[Ⅰ>2σ(Ⅰ)]。在配合物中,每个Mn(Ⅱ)的配位环境都是三角双锥,每个Mn(Ⅱ)离子同时与3个配体配位,每个配体L通过其两臂乙酰丙酮亚胺单元的端基氧原子同2个金属离子配位桥连形成二维网状结构。     

新荧光试剂4-氨基安替比林芳香席夫碱的合成

新荧光试剂4-氨基安替比林芳香席夫碱的合成     

Theoretical study on electronic structures,spectra, and charge transporting properties of two Pt(II) complexes with triazenido ligands

Russian Journal of General Chemistry - Two compounds 1-[(2-carboxymethyl)benzene]-3-[2-pyridine]triazene (HL) and 1-[(2-carboxymethyl) benzene]-3-[o-aminobenzoic acid]triazene (H2L') and two...     

Theoretical study on the influence of ancillary ligand on the spectroscopic properties and electronic structures of phosphorescent Pt(II) complexes

The geometries, energies, and electronic properties of a series of phosphorescent Pt(II) complexes including FPt, CFPt, COFPt, and NFPt have been characterized within density functional theory DFT calculations which can reproduce and rationalize experimental results. The properties of excited‐states of the Pt(II) complexes were characterized by configuration interaction with singles (CIS) method. The ground‐ and excited‐state geometries were optimized at the B3LYP/LANL2DZ and CIS/LANL2DZ levels, respectively. In addition, we also have performed a triplet UB3LYP optimization for complex FPt and compared it with CIS method in the emission properties. The datum (562.52 nm) of emission wavelength for complex FPt, which were computed based on the triplet UB3LYP optimization excited‐state geometry, is not agreement with the experiment value (500 nm). The absorption and phosphorescence wavelengths were computed based on the optimized ground‐ and excited‐state geometries, respectively, by the time‐dependent density functional theory (TD‐DFT) methods. The results revealed that the nature of the substituent at the phenylpyridine ligand can influence the distributions of HOMO and LUMO and their energies. Moreover, the auxiliary ligand pyridyltetrazole can make the molecular structure present a solid geometry. In addition, the charge transport quality has been estimated approximately by the predicted reorganization energy (λ). Our result also indicates that the substitute groups and different auxiliary ligand not only change the nature of transition but also affect the rate and balance of charge transfer. By summarizing the results, we can conclude that the NFPt is good OLED materials with a solid geometry and a balanced charge transfer rate. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010     

Theoretical study of the electronic spectra of square-planar platinum (II) complexes based on the two-component relativistic time-dependent density-functional theory

In the present work the electronic spectra of [PtCl(4)](2-), [PtBr(4)](2-), and [Pt(CN)(4)](2-) are studied with a recently proposed relativistic time-dependent density-functional theory (TDDFT) based on the two-component zeroth-order regular approximation and a noncollinear exchange-correlation (XC) functional. The contribution to the double group excited states in terms of singlet and triplet single group excited states is estimated through the inner product of the transition density matrix obtained from two-component and scalar relativistic TDDFT calculations to better understand the double group excited states. Spin-orbital coupling effects are found to be very important in order to simulate the electronic spectra of these complexes. The results show that the two-component TDDFT formalism can afford excitation energies with high accuracy for the transition-metal systems studied here when use is made of a proper XC potential.     

Theoretical studies of electronic absorption and emission spectra of Pt(saloph)

The performance of ab initio calculations for the ground and excited states of the Pt(saloph) complex is examined in detail. The S₀–S_i and T₁–T_i absorption spectra are calculated, and the transition between the ground S₀ state and the excited S₁ state involves the HOMO-2, HOMO-1, HOMO and LUMO. Moreover, calculations show that the emissive singlet is of mixed MLCT/LLCT characteristic. On the other hand, the molecular geometry of the complex is nearly planar in the ground state while the geometry is obviously nonplanar in the excited state of S₁(π, π^*) in the gas phase.     

Theoretical study of the electronic spectroscopy of CO adsorbed on Pt(111)

The excited states of CO adsorbed on the Pt(111) surface are studied using a time-dependent density functional theory formalism. To reduce the computational cost, electronic excitations are computed within a reduced single excitation space. Using cluster models of the surface, excitation energies are computed for CO in the on-top, threefold, and bridge binding sites. On adsorption, there is a lowering of the 5sigma orbital energy. This leads to a large blueshift in the 5sigma- -> pi(CO*) excitation energy for all adsorption sites. The 1pi and 4sigma orbital energies are lowered to a lesser extent, and smaller shifts in the corresponding excitation energies are predicted. For the larger clusters, pi* excitations at lower energies are observed. These transitions correspond to excitations to virtual orbitals of pi* character which lie below the pi* orbitals of gas phase CO. These orbitals are associated predominantly with the metal atoms of the cluster. The excitation energies are also found to be sensitive to changes in the adsorption geometry. The electronic spectrum of CO on Pt(111) is simulated and the assignment of the bands observed in experimental electron energy loss spectroscopy discussed.     

Pt(II) complexes of 4-amino-4H-1,2,4-triazole

The coordination ability of 4-amino-4H-1,2,4-triazole with Pt(II), both in solution and solid states, is elucidated by conventional and linear-polarized IR spectroscopy of oriented colloid suspensions in nematic host, ¹H- and ¹³C-NMR, UV-Vis spectroscopy, mass spectrometry (ESI and FAB), TGV, and DSC methods. The interpretation of the spectroscopic characteristics of corresponding metal complexes is obtained by comparison with free 4-amino-4H-1,2,4-triazole. In addition, quantum chemical calculations of the last compound are performed to obtain data for electronic structures and optical properties of the ligand, thus supporting the experimental elucidation. The evaluation of the cell viability on a panel of human tumor cell lines is made. The new Pt(II) complexes exerted cytotoxic effects in a concentration-dependent manner.     

Data base for electronic spectra of metal complexes

An information system for electronic spectra of transition elements called ESTE—DBS (DBS for data base system) has been described and discussed. This relational system is divided in two main parts, one containing data extracted from experimental spectra, the second created by simulation on the basis of the ligand field theory and some empirical parameters.