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1.
合成、鉴定了具有离子识别功能的题示光敏离子载体(6,7-二甲氧基-4-亚甲基香豆素基)单氮杂-18-冠-6 (DMC-MAC(O5)),研究了它在水中的吸收和荧光光谱,基于不同pH值水溶液中荧光光谱的变化,计算得该试剂激发态分子的酸性常数pKa= 6.00。基于在不同溶剂中荧光光谱的变化,由Solvachrom ic法,利用Lippert方程并借助Alchem y 2000量化计算软件,采用分子力学模型(MM3),估算得该分子的基态和激发态偶极矩,分别为2.75D和7.84D。DMC-MAC(O5)保留了6,7-二甲氧基香豆素(DMC)优良的发光性能,为其离子识别功能的研究奠定了良好的基础。  相似文献   

2.
合成、鉴定了具有离子识别功能的题示光敏离子载体(6,7-二甲氧基-4-亚甲基香豆隆基)单氮杂-18-冠-6(DMC-MAC(O5),研究了它在水中的吸收和荧光光谱,基于不同pH值水溶液中荧光光谱的变化,计算得该试剂激发态分子的酸性常数pKa^*=6.00。基于在不同溶剂中荧光光谱的变化,由Solvachromic法,利用Lippert方程并借助Alchemy2000量化计算软件,采用分子力学模型(  相似文献   

3.
利用一维和二维NMR技术,对含有手性膦配体的铂配合物cis-〔Pt(2-MBPAH)2Cl2〕(1),trans-〔Pt(2-MBPAH)2Cl2〕(2),cis-〔Pt(2-MBPA)2〕(3)和cis-〔Pt(2-MBPA)(2-MBPAH)Cl〕(4)进行1H和13CNMR谱分析,区分了化合物(3)和(4),归属了糖苷部分的1H和13CNMR谱线,并根据磷和铂及磷与磷的偶合常数确定化合物(3)和(4)是顺式构型  相似文献   

4.
本文研究了以甲苯为溶剂,AlCl3和BF3·OEt2为引发剂,1,3-戊二烯(PD)与苯乙烯(St)的阳离子共聚合反应,并用红外光谱测定聚合物的微观结构。由共聚单体PD和St加入顺序的不同可生成无规共聚物P(PD-co-St)和接枝共聚物P(PD-g-St)和P(St-g-PD)。无论是由AlCl3引发聚合反应,还是由BF3·OEt2引发聚合反应,St上的碳阳离子的活性都高于PD上碳阳离子的活性。由AlCl3首先引发PD进行聚合反应,结束后再引入St时,聚合体系不能引发St聚合反应;相反AlCl3首先引发St聚合后的体系能继续引发PD的聚合反应。BF3·OEt2无论先引发St或是PD,都能在聚合反应完成后接着引发另一单体而生成接枝共聚物P(PD-g-St)和P(St-g-PD)。二苯醚与烯丙基氯的加入,提高了碳阳离子的稳定性,增加了聚合物的分子量,但降低了碳阳离子的活性,使得聚合反应的产率降低,同时对St和PD碳阳离子的活性次序无明显影响  相似文献   

5.
建立了用丹磺酰氯定性鉴定吡咯喹啉醌的薄层色谱法。甲基营养菌No.2培养液经二乙氨基乙基交联葡聚糖凝胶A-25离子交换剂、Sep-Pak C18 Cartridge纯化后,可获得纯度92%以上的吡咯喹啉醌(PQQ)粉末。在碱性条件下丹磺酰氨(DNS-Cl)可与PQQ生成具有特征性的DNS-N-PQQ荧光衍生物,将其点祥于聚酰胺薄膜上,经正庚烧-正丁醇-醋酸(体积比3:3:1)系统展开,Rf值为0.7  相似文献   

6.
合成了新的十一个2-(N-十六烷基氨基甲酰基)-8-羟基喹啉(C26H39N2O2,简写为HL)的配合物[ML2],(M=Mn(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Zn(Ⅱ)、Cd(Ⅱ)、Pd(Ⅱ)、Mg(Ⅱ)和Ca(Ⅱ))、[ML2Cl(H2O)4](M=La(Ⅲ)、Ga(Ⅲ))和[CuLCl],并经元素分析、摩尔电导、磁性和红外光谱所表征。红外光谱表明:配合物是以三齿形式与金属离子配位。配合物中C-O键伸缩振动频率与中心金属离子的相对原子质量或中心离子的电离势呈双线性关系。  相似文献   

7.
合成了[Mn_2(bzacen)_2(MeOH)_2(μ-4,4′-bipy)](ClO_4)_2化合物,并测定其晶体结构。该晶体属单斜晶系,空间群P2_1/n,晶胞参数:a=1.3082(3)nm,b=1.2713(3)nm,c=1.8006(5)nm,β=110.91(2)°,Z=2,μ=5.97cm-1,R=0.0580,GOF=1.66.在配合物阳离子中,4,4′-联吡啶桥联2个[Mn(bzacen)(MeOH)]+,而锰原子具有3个N原子和3个O原子形成的扭曲八面体配位构型。红外光谱和拉曼光谱均表明,形成配合物后,v_(C=N)、v(C=O)、和v(C=C)移向低频。红外光谱的1110cm ̄(-1)谱带表明ClO_4 ̄-未与Mn(Ⅲ)配位,812cm ̄(-1)振动说明4,4′-bipy充当桥联二齿配体。拉曼光谱中的463cm ̄(-1)和401cm ̄(-1)别为Mn-O和Mn-N的振动带。电子光谱证明存在d-d、d-π和π-π跃迁。电极电位测定显示该配合物Mn(Ⅲ)的价态是稳定的。  相似文献   

8.
以1-(2-噻唑偶氮)-2-萘酚(TAN)作柱前显色剂,于ODS柱上,用内含0.1mol/LLiCl,5×10-6mol/L TAN和HAc-NH4Ac缓冲溶液(pH 5.5)的甲醇-水溶液(80:20,V/V)作流动相,流速为0.6mL/min,并以紫外-可见检测器于590nm处进行检测,发展了一种RP-HPLC法同时分离测定铜(Ⅱ)、铁(Ⅱ)、镍(Ⅱ)的方法,方法灵敏度高,对于铜、铁、镍的检测限分别为1μg/L, 2 μg/L和 0.4 μg/L。用于实际样品测定,结果满意。  相似文献   

9.
合成了三种以2-溴代对苯二甲酸根为桥联配体的新型双核钴(Ⅱ)的配合物,即[Co2(BTP)(phen)4](ClO4)2·H2O(配合物1)、[Co2(BTP)(Nphen)4](ClO4)2·2H2O(配合物2)和[Co2(BTP)(Bpy)4](ClO4)2·2H2O(配合物3)(BTP=2-溴代对苯二甲酸根,phen=1,10-菲罗啉,Nphen=5-硝基-1,10-菲罗啉,Bpy=2,2′-联吡啶)。使用元素分析、IR、UV-Vis光谱和电导测定方法对该配合物进行了表征。测定了配合物的变温磁化率,并对所得数据进行了理论分析,求得了配合物1、配合物2和配合物3的自旋磁交换积分分别为:2J=-6.5cm-1,2J=-7.8cm-1和2J=-8.9cm-1。对该三配合物进行了体外抗人白血病癌细胞的实验。发现该三配合物均具有一定的抑制癌细胞的活性  相似文献   

10.
研究了四元体系CsCl-LaCl3-HCl-H2O(25℃、「HCl」=13%(wt),23%(wt)和CsCl-LaCl3-HAc-H2O(30℃,「HAc」=42%(wt))的平衡态的溶度数据,并给出制了相应的溶度图,共得到了CsCl.LaCl3.4H2O、2CsCl.LaCl3.2H2O和3CsCl.LaCl3.3H2O3种化合物。对得到的新相进行了热分析,X射线粉末衍射及偏光性质的测定,依  相似文献   

11.
The absorption and fluorescence spectra of N-nonyl acridine orange are determined at room temperature (298 K) in cyclohexane, benzene, carbon tetrachloride, chloroform, chlorobenzene and dichloromethane. The ground state of dipole moment was obtained by impedance measurements using Guggenheim-Debeye's method. The experimental excited state dipole moment of N-nonyl acridine orange was determined using Bakhshiev's and Kawski-Chamma-Viallet's formulae and solvent polarity parameter proposed by Reichardt. These experimental results were completed with theoretical results using quantum chemical methods. The experimental (muexp=10.76 D) and theoretical (mucal=9.9 D) dipole moments in the ground and excited state (muexp*=14.56 D) were compared.  相似文献   

12.
刘涛  魏用刚  袁燕秋  郭庆祥 《中国化学》2005,23(10):1430-1436
A series of N-bonded donor-acceptor derivatives of phenothiazine containing phenyl (PHPZ), anisyl (ANPZ), pyridyl (PYPZ), naphthyl (NAPZ), acetylphenyl (APPZ), and cyanophenyl (CPPZ) as an electron acceptor have been synthesized. Their photophysical properties were investigated in solvents of different polarities by absorption and emission techniques. These studies clearly revealed the existence of an intramolecular charge transfer (ICT) excited state in the latter four compounds. The solvent dependent Stokes shift values were analyzed by the modified Lippert-Mataga equation to obtain the excited state dipole moment values. The large excited state dipole moment suggests that the full (or nearly full) electron transfer take place in the A-D systems. In the system of A-D phenothiazine derivatives, the transition dipole moments Mflu were determined mainly by direct interactions between the solvent-equilibrated fluorescence ^1CT state and ground state because of their lack of significant change with increase of the solvent polarity. The electron structure and molecular conformation of phenothiazine derivatives will be significantly changed with the increase of the electron affinity of the N-10 substituent.  相似文献   

13.
The one-photon absorption (OPA) properties of donor-pi-bridge-acceptor-pi-bridge-donor (D-pi-A-pi-D)-type 2,1,3-benzothiadiazoles (BTD) were studied with two dimensional (2D) site and three dimensional (3D) cube representations. The 2D site representation reveals the electron-hole coherence on electronic state transitions from the ground state. The 3D representation shows the orientation of transition dipole moment with transition density, and the charge redistribution on the excited states with charge difference density. In this paper, we further developed the 2D site and 3D cube representations to investigate the two-photon absorption (TPA) properties of D-pi-A-pi-D-type BTD on electronic transitions between excited states. With the new developed 2D site and 3D cube representations, the orientation of transition dipole moment, the charge redistribution, and the electron-hole coherence for TPA of D-pi-A-pi-D-type BTD on electronic state transitions between excited states were visualized, which promote deeper understanding to the optical and electronic properties for OPA and TPA.  相似文献   

14.
A series of N-bonded donor-acceptor derivatives of phenothiazine containing benzene (PHPZ), anisole (ANPZ), pyridine (PYPZ), naphthalene (NAPZ), acetophenone (PEPZ), and benzonitrile (BNPZ) as an electron acceptor was synthesized. Their photophysical properties were investigated in solvents of different polarities by absorption and emission techniques. These studies clearly reveals the existence of an intramolecular charge transfer (ICT) excited state in the latter four compounds. The solvent dependent Stokes shift values were analyzed by the modified Lippert-Mataga equation to obtain the excited state dipole moment values. The large excited state dipole moment suggests that the full electron transfer takes place in the A-D systems. The obtained values of redox potentials indicate that both subunits of all the A-D molecules studied interact very weakly in the ground states. The results obtained from the analysis of the CT fluorescence spectra confirm that the small conformational changes accompanying excited state charge transfer, the twist angle between the donor and acceptor moieties in the excited 1CT state seems to be similar to that in the ground state.  相似文献   

15.
The ground state and excited state dipole moment of a series of alkyl substituted para-nitroaniline derivatives is reported. Ground state dipole moment was determined by the Debye-Guggenheim method and the excited state dipole moment was estimated using the solvatochromic method. For all molecules under investigation, the excited state dipole moment was found to be higher than the ground state dipole moment. The molecules exhibited positive solvatochromism.  相似文献   

16.
NF (nitrogen monofluoride, fluoroimidogen) is isoelectronic with O2, and, like O2, it has a triplet configuration in the ground state, with two low-lying metastable singlet excited states. The dipole moment of the a 1Delta excited state was measured in 1973 to be 0.37 +/- 0.06 D; at the time its polarity was assumed to be normal (i.e., with the negative charge on the fluorine). However, high-level electronic structure calculations, which reproduce with high accuracy the known spectroscopic constants of the ground and excited states of NF, predict a dipole moment of -0.388 D for a 1Delta NF, indicating that, despite the electronegativities, this molecule carries a positive charge on fluorine. The other singlet state is predicted to have an even larger negative dipole moment; the ground-state triplet should have a very small positive moment. Singlet NF resembles in this respect CO and BF, from the N2 isoelectronic series, both of which also have negative dipole moments.  相似文献   

17.
Electronic absorption and dual fluorescence spectra of 6,8-diphenylimidazo[1,2-α]pyrazine (68DIP) was recorded in various solvents with different polarity at room temperature. The ground state (μg) and the excited state (μg) dipole moments of 68DIP were estimated from solvatochromic shifts of absorption and fluorescence spectra as a function of the dielectric constant (?) and refractive index (n). The results show that the value of excited state dipole moment in SE: μeSE=2.8772 D and twisted intramolecular charge transfer (TICT) excited equilibrated state dipole moment value of μeLE=2.9744 D was found. The solvent dependent spectral shifts in absorption and fluorescence spectra were analyzed by the polarizability-polarity and Kamlet-Taft parameters.  相似文献   

18.
Electronic structure and photophysical properties of 2-(N,N-diethylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3,5-triazine are studied theoretically with quantum chemical methods as well as 2D site and 3D cube representations. The theoretical results reveal that the first excited state is an intramolecular charge transfer excited state. The change in dipole moment for the first excited state of the excitation is fitted, and the calculated result the change in dipole moment ¢1=6.40 D is consistent with the experimental result ¢1=6.90 D. The polarizability is also fitted. The large changes in dipole moment and the polarizability of the excitation show that S1 is of large nonlinear optical (NLO) effect. The NLO will promote efficient two-photon-absorption cross sections. The excited state properties of dpbt with different external electronic fields are also discussed theoretically.  相似文献   

19.
The permanent dipole moments of excited molecules can be obtained from the ratio of the solvent shifts of absorption and fluorescence spectra. This ratio method eliminates the uncertain solute cavity radius parameter, as well as the solvent polarity function. In the case of the first excited singlet state of aniline the dipole moment is 5 D (versus 1.57 D in the ground state).  相似文献   

20.
MgH2分子的激发态研究   总被引:1,自引:0,他引:1  
本文采用SCF、MCSCF、SOCI方法对MgH_2的基态和两个激发态进行了计算研究,预言了各态的平衡几何构型、总能量、偶极矩、电荷分布等性质,并首次报道了各态的振动频率。  相似文献   

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