Ce(Ⅳ)、Th(Ⅳ)与1,10-二氮杂菲-1-氧化物及乙酰丙酮的三元配合物

三元配合物的形成可明显改变单一配体配合物的性质,它们在分析、分离化学中已有广泛的研究和应用。由于Ce(Ⅳ)的强氧化性致使其三元配合物的合成较为困难。我们曾合成出三价稀土与1,10-二氮杂菲-1-氧化物(PhenNO)及乙酰丙酮(Hacac)的三元配合物。作为该工作的继续,本文研究了Ce(Ⅳ)、Th(Ⅳ)与PhenNO及Hacac三元配合物的合成与     

系列Ln(Ⅲ)配位聚合物(Ln:Eu,Sm,Tb,Gd)的合成及其荧光分析

采用水热法合成了4个具有1D结构的Ln(Ⅲ)配位聚合物,[Eu2(C9H7O2)6(C9H7O2H)(C2H5OH)]n(1)、[Sm(C9H7O2)3]n(2)、[Tb(C9H7O2)3]n(3)和[Gd(C9H7O2)3]n(4)(C9H8O2=肉桂酸)。通过X射线单晶衍射确定了它们的结构。这4个Ln(Ⅲ)配合物中,Ln(Ⅲ)的配位数均为9,桥配体均为肉桂酸根,但其配位方式有差异。对配合物进行了IR、UV-Vis-NIR和荧光光谱等表征。分析了各配合物的荧光发射,结果表明,在可见区,配合物1发射较明显的红光,配合物2、3发射绿光,配合物4发射蓝光,但很弱。讨论了具有刚柔相混杂性质的肉桂酸配体对配位聚合物的构筑及稀土离子发光的影响。     

Al(Ⅲ)-槲皮素配合物的光谱分析

采用UV和IR分析手段,研究在甲醇溶剂酸性和中性条件下,槲皮素(3,3,′4,′5,7-五羟基黄酮)与A l(Ⅲ)形成配合物的构型、反应配比及在配位反应过程中配体分子中各个配位点的配位能力大小及优先配位的顺序。实验结果表明:在酸性介质中,槲皮素与A l(Ⅲ)所形成配合物的反应配比为A l(Ⅲ)∶Q=1∶1,其配位点为3-羟基-4-酮,配位构型中心为A l(Ⅲ)与一个槲皮素分子形成五元环四配位的配合物。在中性介质中发生两步配位反应,第一步配位反应发生在3-羟基-4-酮配位点其反应配比为1∶2,配位构型为中心A l(Ⅲ)与两个槲皮素分子形成两个五元环之间四配位的配合物;第二步配位反应发生在3,′4′-二羟基配位点其反应配比为2∶1,两个A l(Ⅲ)离子分别在上述两个配位点与一个槲皮素分子形成五元环四配位构型的配合物。     

锑(Ⅲ)配合物的合成及其空间立体化学

含锑(Ⅲ)配合物涉及到许多化学及生物化学的过程,特别是它的一些配合物具有一定的抗癌、杀菌等生物功能,其空间结构的多样性也一直吸引着人们的注意力。本文按照O供电子配体,含N供电子配体和含S供电子配体分类,系统地综述了各类锑(Ⅲ)配合物的合成方法及表征手段,介绍了锑(Ⅲ)配合物的分子结构及其晶体学参数和配位环境中孤电子对空间化学活性,展望了锑的生物无机配合物的合成与应用前景。     

含吡啶基十四元六氮大环配体与Ni(Ⅱ)配合物的合成及性质的研究

金属四氮大环配合物的合成及性能的研究对于探讨生理过程,人工模拟具有一定的意义,本文研究的一种四氮配位的大环配合物是含有吡啶基的十四元四氮配位的大环配合物(图1),关于此类配合物的合成工作始于1974年,最早由Goedken和Paryzek合成了Fe(Ⅱ)、Mg(Ⅱ)、Zn(Ⅱ)、Sc(Ⅲ)的这类配合物。     

La(Ⅲ),Sm(Ⅲ)与低分子量壳聚糖配合物的合成及性质

以低分子量壳聚糖(CTS')与稀土金属离子镧La(Ⅲ)、钐Sm(Ⅲ)在pH值4～5的条件下制备低分子量壳聚糖稀土金属离子配合物(La(Ⅲ)-CTS',Sm(Ⅲ)-CTS').通过紫外光谱(UV)、红外光谱(IR)、1H核磁共振、热失重分析对配合物进行表征,得出稀土金属离子和CTS'之间以氨基和羟基进行配位,配合物的热稳定性低于CTS'.最低抑菌浓度(MIC)试验表明,CTS'及其配合物对革兰氏阳性球菌和革兰氏阴性杆菌的最低抑菌浓度分别为4和5 g·L-1.     

喹啉氧基乙酰胺的Pr(Ⅲ)、Nd(Ⅲ)、Sm(Ⅲ)配合物的结构、表征和荧光性质

合成并通过单晶衍射表征了3个同构稀土配合物Ln(L)(NO3)3(H2O)(L=N-苯基-2-(5-氯-8-喹啉氧基)乙酰胺,Ln=Pr(Ⅲ),1;Nd(Ⅲ),2;Sm(Ⅲ),3)。在每个配合物中,十配位的稀土离子采取扭曲的双帽四方反棱柱配位构型,分别与来自1个配体L的2个氧原子和1个氮原子,2个双齿配位硝酸根和1个水分子配位。配合物3能够发射Sm(Ⅲ)离子特征荧光,荧光寿命为11.7μs。     

含稀土铕(Ⅲ)配位聚合物的研究——铕(Ⅲ)噻吩甲酰三氟丙酮苯乙烯丙烯酸共聚物的研究

研究了铕 (Ⅲ )和噻吩甲酰三氟丙酮 (HTTA)形成的有机配合物与苯乙烯 丙烯酸共聚物 (PSAA)在不同pH值时发生配位反应得到配位聚合物NaEu(Ⅲ ) TTA PSAA的 3种样品 (a)、(b)、(c) .红外光谱、紫外光谱、X光电子能谱、DTA TG等测试手段证实Eu3+ 分别与PSAA、TTA- 发生配位 .元素分析和电导率测定结果证明了配位组成和结构在不同的pH条件下发生变化 .结果表明 ,配合物试样 (a)、(b)、(c)中Eu3+ 的含量分别为11 89%、12 5 5 %和 13 4 1% .由于配合物中存在着Eu3+ 分别与TTA- 和PSAA分子中羧基的配位作用并进一步交联 ,因此配合物样品均不溶于大部分有机溶剂 ,只能溶于N ,N 二甲基甲酰胺和丙三醇和异丙醇的混合溶剂 ,而且耐热性能均提高 .该配合物均是褐色固体 .荧光光谱表明 ,样品在常温、紫外光下发出强的红光 ,主要是Eu离子的5D0 →7F2 的跃迁 .讨论了溶剂、pH值对配合物荧光强度的影响 .当pH =10时 ,合成的配合物有最好的荧光性质 .     

尾式金属卟啉配合物的研究(Ⅲ)──咪唑基尾式卟啉及其铁(Ⅲ)配合物的合成和性质

合成了咪唑基尾式卟啉──5-邻[4-(1-咪唑基)丁氧基]苯基-10,15,20-三苯基卟啉(o-ImBPTPP)及其铁(Ⅲ)配合物[Fe(Ⅲ)(o-ImBPTPP)Cl],以元素分析、质谱、¹HNMR、IR和紫外可见吸收光谱等进行了表征.初步研究了在氯仿和苯中某些含氮配体与铁(Ⅲ)配合物的轴向配位性质.结果表明,Fe(Ⅲ)(o-ImBPTPP)Cl通常与含氮配体生成低自旋的六配位加合物,但在苯溶液中与咪唑作用时,一定条件下还能生成稳定的高自旋五配位加合物.     

1,10-二氮杂菲-1-氧化物与高氯酸钪、钇的配合物

吡啶类氮氧化物与过渡金属离子能形成稳定的配合物,其中某些配合物具有荧光。在寻找新型发光材料中,这类配合物引起了人们的重视,使这类配合物的合成与性质研究工作得了到广泛的开展。钪、钇与其它吡啶类氨氧化物的配合物已有研究,但与1,10—二氮杂菲—1—氧化物(PhenNO)的配合物至今未见报道,本文研究了钪、钇高氯酸盐与PhenNO配合物的合成及有关性质。     

Controlling the nature of mixed (phthalocyaninato)(porphyrinato) rare-earth(III) double-decker complexes: the effects of nonperipheral alkoxy substitution of the phthalocyanine ligand

The half-sandwich rare-earth complexes [M(III)(acac)(TClPP)] (M = Sm, Eu, Y; TClPP = meso-tetrakis(4-chlorophenyl)porphyrinate; acac = acetylacetonate), generated in situ from [M(acac)3] x n H2O and H2(TClPP), were treated with 1,8,15,22-tetrakis(3-pentyloxy)phthalocyanine [H2{Pc(alpha-OC5H11)4}] (Pc = phthalocyaninate) under reflux in n-octanol to yield both the neutral nonprotonated and protonated (phthalocyaninato)(porphyrinato) rare-earth double-decker complexes, [M(III){Pc(alpha-OC5H11)4}(TClPP)] (1-3) and [M(III)H{Pc(alpha-OC5H11)4}(TClPP)] (4-6), respectively. In contrast, reaction of [Y(III)(acac)(TClPP)] with 1,4,8,11,15,18,22,25-octakis(1-butyloxy)phthalocyanine [H2Pc(alpha-OC4H9)8] gave only the protonated double-decker complex [Y(III)H{Pc(alpha-OC4H9)8}(TClPP)] (7). These observations clearly show the importance of the number and positions of substituents on the phthalocyanine ligand in controlling the nature of the (phthalocyaninato)(porphyrinato) rare-earth double-deckers obtained. In particular, alpha-alkoxylation of the phthalocyanine ligand is found to stabilize the protonated form, a fact supported by molecular-orbital calculations. A combination of mass spectrometry, NMR, UV-visible, near-IR, MCD, and IR spectroscopy, and X-ray diffraction analyses, facilitated the differentiation of the newly prepared neutral nonprotonated and protonated double-decker complexes. The crystal structure of the protonated form has been determined for the first time.     

Theoretical study on vibrational circular dichroism spectra of tris(acetylacetonato)metal(III) complexes: anharmonic effects and low-lying excited states

The open-shell density functional theory calculations with M06 exchange-correlation functional and all-electron Douglas-Kroll second order scalar relativistic correction were performed to interpret the vibrational circular dichroism (VCD) spectra of four kinds of tris(acetylacetonato)metal(III), [M(III)(acac)(3)] (acac = acetylacetonato, M = Ru, Cr, Co, and Rh). It was deduced that the experimental spectra were well reproduced by the calculation with harmonic approximation in case of [Co(III)(acac)(3)] (d(6); S = 0), [Rh(III)(acac)(3)] (d(6); S = 0), and [Ru(III)(acac)(3)] (d(5); S = 1/2). In case of [Cr(III)(acac)(3)] (d(3); S = 3/2), anharmonic effects should be taken into account to predict the accurate vibrational frequencies of closely located modes. Time-dependent density functional theory calculations were performed to estimate the contribution of excited states in the VCD spectra. As a consequence, the presence of the low-lying excited states was predicted for [Ru(III)(acac)(3)] alone, which agreed with the experimental observation.     

Induction and structural control of chiral nematic phases by the use of photoresponsive tris(beta-diketonato) Co(III) and Ru(III) complexes

Two kinds of tris(beta-diketonato) metal(III) complexes denoted as [M(acac)2(LC12)] and [M(acac)2(Lazo)] (M=Ru(III) and Co(III); acac=acetylacetonato; LC12=1,3-didodecyloxyphenyl-1,3-propanedionato; Lazo=3-[4'-(4'-(butoxy)phenylazo)phenyl]-pentane-2,4-dionato) were synthesized and optically resolved into Delta, Lambda isomers. Here, LC12 and Lazo were designed to be elongated perpendicular to and in parallel with the molecular C 2 axis, respectively. The metal complexes were doped into three kinds of nematic liquid crystals (MBBA, EBBA, and ZLI-1132). Both dopants induced chiral nematic phases with relatively high helical twisting powers. With a purpose to clarify the mechanisms of helical induction, order parameters (S) were determined by means of polarized UV-vis measurements on nematic samples doped with racemic Co(III) complexes. As a result, the long axes of the elongated ligands in both [Co(acac)2(LC 12)] and [Co(acac)2(trans-Lazo)] were found to align in the direction of the director vector with S=0.50+/-0.05 and 0.60+/-0.05, respectively. Based on the results, the photoresponsive behavior of Delta- or Lambda-[Ru(acac)2(Lazo)] was interpreted in terms of the variation of S accompanied with the cis-trans isomerization of the azobenzene moiety in Lazo.     

Synthesis of heteroleptic anthryl-substituted beta-ketoenolates of rhodium(III) and iridium(III): photophysical,electrochemical, and EPR study of the fluorophore-metal interaction

The anthryl-substituted rhodium(III) and iridium(III) heteroleptic beta-ketoenolato derivatives of general formula [M(acac)(2)(anCOacac)] [acac = pentane-2,4-dionate; anCOacac = 3-(9-anthroyl)pentane-2,4-dionate], 3 (M = Rh) and 4 (M = Ir), and [M(acac)(2)(anCH(2)acac)] [anCH(2)acac = 3-(9-anthrylmethyl)pentane-2,4-dionate], 5 (M = Rh) and 6 (M = Ir), were prepared by reacting the corresponding tris(pentane-2,4-dionate)metal complexes, [M(acac)(3)], with 9-anthroyl chloride and 9-chloromethylanthracene, respectively, under Friedel-Crafts conditions. 3-6 were characterized by elemental analysis, ion spray mass spectrometry (IS-MS), (1)H NMR, and UV-vis spectroscopy. The structure of 3 was also elucidated by single-crystal X-ray analysis. When excited at 365 nm, 3-6 result to be poorly luminescent compounds; while the free diketone, i.e., 3-(9-anthrylmethyl)pentane-2,4-dione 1, whose structure was established also by single-crystal X-ray analysis, results to be a strongly light emitting molecule. The study of the electrochemical behavior of 3-6 as well as of the corresponding tris-acetylacetonates of rhodium(III) and iridium(III) allows a satisfactory interpretation of their electrode process mechanism, and gives information about the location of the redox sites along with the thermodynamic and kinetic characterization of the corresponding redox processes. All data are in agreement with the hypothesis that the quenching of the anthracene fluorescence, observed for compounds 3-6, can be due to an intramolecular electron transfer process between the anthryl moiety and the metal-beta-ketoenolato component. Moreover, a study was carried out of the redox behavior of the dyads 3-6 under chemical activation. The one-electron oxidation of compounds 3-6 by thallium(III) trifluoroacetate leads to the formation of the corresponding cation radicals, 3(+)-6(+), whose highly resolved X-band EPR spectra were fully interpreted by computer simulation as well as by semiempirical and DFT calculations of spin density distribution.     

镧系无素与今菲咯啉单氮氧化物及乙酰丙酮三元络合物的研究

本文合成十三种镧系元素与邻菲咯啉(Phenno)单氮氧化物及乙酰丙酮(Hacac)的三元配合物, 元素分析确定配合物的组成为Ln(phenno)(acac)3(Ln=La,Pr,Nd,Sm-Lu)。对该系列配合物的红外光谱, 紫外光谱, 热谱及电导等性质进行了研究,Sm(Phenno)(acac)3的X射线单晶结构分析表明, 金属离子与三个acac及一个Phenno的七个氧一个氮原子配位, 配位数为八, 配位多面体为变形十二面体。     

Effects of central metal ions on vibrational circular dichroism spectra of tris-(beta-diketonato)metal(III) complexes

Vibrational circular dichroism (VCD) spectra of a series of [M(III)(acac)3] (acac = acetylacetonato; M = Cr, Co, Ru, Rh, Ir, and Al) and [M(III)(acac)2(dbm)] (dbm = dibenzoylmethanato; M = Cr, Co, and Ru) have been investigated experimentally and/or theoretically in order to see the effect of the central metal ion on the vibrational dynamics of ligands. The optical antipodes give the mirror-imaged spectra in the region of 1700-1000 cm(-1). The remarkable effect of the central metal ion is observed experimentally on the VCD peaks due to C-O stretches (1500-1300 cm(-1)) for both [M(III)(acac)3] and [M(III)(acac)2(dbm)]. In the case of Delta-[M(III)(acac)3], for example, the order of frequency of two C-O stretches (E and A2 symmetries) is dependent on the kind of a central metal ion as follows: E (-) > A2 (+) for M = Co, Rh, and Ir, while A2 (+) > E (-) for M = Cr and Ru. In the case of Delta-[M(III)(acac)2(dbm)], the order of frequency of three C-O stretches (A, B, and B symmetries) is as follows: A (-) > B (+) > B (+) for Co(III), B (+) > A (-) > B (-) for Cr(III), and A (-) > B (+) > B (-) for Ru(III). These results imply that the energy levels of C-O stretches are delicately affected by the kind of central metal ion. Since such detailed information is not obtained from the IR spectra alone, the VCD spectrum can probe the effect of the central metal ion on interligand cooperative vibration modes.     

Aluminum(III), gallium(III), and indium(III) 4-hydroxyacridinato complexes

4-Hydroxyacridine (HAcr) is an O,N-chelating ligand whose coordination chemistry toward group 13 M(III) ions has received little attention. The molecular structure of HAcr consists of a 2,3-disubstituted-8-hydroxyquinoline; thus, in order to compare 8-hydroxyquinoline (HQ), 2-methyl-8-hydroxyquinoline (HMeQ′), and 2,3-disubstituted-8-hydroxyquinoline (HAcr) for steric and/or electronic influence, HAcr chelating ability toward the Al(III), Ga(III), and In(III) triad has been investigated. Irrespective of the nature of M(III), only complexes containing two equivalents of deprotonated HAcr are obtained. This article describes the synthesis and characterization of different series of bis-chelated pentacoordinated (Acr)₂MY (M = Al, Ga, In; Y = Cl, Br, I, NCS, N₃) or (Acr)₂MZ (M = Ga or In; HZ = C₆H₅OH, C₆H₁₃OC₆H₄OH, C₆H₅COOH, or C₆H₁₃OC₆H₄COOH) six-coordinate neutral (Acr)₂In(acac) (H(acac) =acetylacetone), or ionic [(Acr)₂In(N,N)][CF₃SO₃] (N,N = 2,2′-bipyridine or 1,10-phenanthroline) complexes. These results significantly contribute to elucidating the complexation capability of HAcr.     

Thermal and spectral studies of 2,4,5-trimethoxybenzoates of heavy lanthanides(III) and yttrium(III)

2,4,5-Trimethoxybenzoates of Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III) and Y(III) are crystalline, hydrated salts with colours typical for M(III) ions. The carboxylate group is a bidenate, chelating ligand. The complexes of Tb(III), Dy(III) and Ho(III) are dihydrates while those of Er(III), Tm(III), Yb(III), Lu(III) and Y(III) are trihydrates. These compounds are characterized by low symmetry. On heating in air to 1273 K, the 2,4,5-trimethoxybenzoates of heavy lanthanides(III) and yttrium(III) decompose in two steps. At first they dehydrate to form anhydrous salts which next are decomposed to the oxides of the respective metals. The values of the enthalpy of dehydration process were determined. The solubility in water at 293 K for all heavy lanthanides(III) and yttrium(III) are in the orders of 10^-3-10^-4 mol dm^-3. The magnetic moments of the complexes were determined in the temperature range 77-300 K.     

Salicylic acid derivatives form stable complexes with scandium(III) ion in aqueous solution

The stability constants of 5-nitrosalicylic acid (5-NSA) and 5-sulfosalicylic acid (5-SSA) complexes of Sc(III) were determined by potentiomeric pH titration. ML and ML2 type first and second complexes were observed in the solutions of 5-NSA and 5-SSA with Sc(III) at 25 degrees C in I=0.1 M ionic medium. The stability constants of Sc(III)-5NSA and Sc(III)-5SSA systems were also investigated by spectrophotometry to determine the stoichiometries of the complexes formed in the reactions. Our results showed that Sc(III)-5SSA complexes are more stable than the Sc(III)-5NSA complexes in aqueous solutions.     

Identification of geometrical isomers using vibrational circular dichroism spectroscopy: a series of mixed-ligand complexes of diamagnetic Co(III) ions

Vibrational circular dichroism (VCD) spectra were measured on the chloroform solutions of a series of mixed-ligand diamagnetic Co(III) complexes, [Co(tfac)(n)(acac)(3-n)] (n = 0-3, tfac = 1,1,1-trifluoro-2,4-pentanedionato; acac = acetylacetonato). Distinct differences were observed in the VCD spectra among the geometrical isomers of the same ligand composition. Such differentiation was hardly possible by their infra-red spectra alone. The structural identification of these isomers was performed in conjunction with DFT calculations.