吡啶-2-羧酸的Dy(Ⅲ)和Tm(Ⅲ)配合物及其与牛血清白蛋白结合性能

以5-(三氟甲基)吡啶-2-羧酸(Htpc)与DyCl₃·6H₂O、TmCl₃·3H₂O构筑了2种异质同晶的单核配合物[M(tpc)₃(H₂O)₃]·H₂O,其中 M=Dy (1)、Tm (2)。配合物 1 和 2 均为单斜晶系,P2₁/c 空间群,中心金属离子为八配位且形成了轻微扭曲的十二面体构型。温度梯度下的荧光和紫外测试表明,2 种配合物均能与牛血清白蛋白(BSA)发生静态猝灭作用,猝灭常数(K_sv)为 10⁵~10⁶ L·mol^-1。配合物与BSA结合过程的ΔH和ΔS均为正值,说明疏水作用在其中扮演重要的角色。25℃时,2种配合物与BSA结合常数约为10⁴ L·mol^-1,表明二者与BSA的具有中等强度的结合力。     

吡啶-2-羧酸的Dy（Ⅲ）和Tm（Ⅲ）配合物及其与牛血清白蛋白结合性能

以5-(三氟甲基)吡啶-2-羧酸(Htpc)与DyCl₃·6H₂O、TmCl₃·3H₂O构筑了2种异质同晶的单核配合物[M(tpc)₃(H₂O)₃]·H₂O,其中M=Dy(1)、Tm(2)。配合物1和2均为单斜晶系,P2₁/c空间群,中心金属离子为八配位且形成了轻微扭曲的十二面体构型。温度梯度下的荧光和紫外测试表明,2种配合物均能与牛血清白蛋白(BSA)发生静态猝灭作用,猝灭常数(K_sv)为105~10⁶ L·mol^-1。配合物与BSA结合过程的ΔH和ΔS均为正值,说明疏水作用在其中扮演重要的角色。25℃时,2种配合物与BSA结合常数约为10⁴ L·mol^-1,表明二者与BSA的具有中等强度的结合力。     

荧光法研究偏钒酸钠与牛血清白蛋白的相互作用

本文用荧光光谱和紫外可见吸收光谱研究了在模拟人体生理条件下，偏钒酸钠与牛血清白蛋白(BSA)结合反应的特征，研究了紫外灯(253.7 nm)照射对偏钒酸钠与BSA结合的影响。紫外吸收光谱显示，加入偏钒酸钠后，牛血清白蛋白的紫外吸收降低，表明偏钒酸钠与BSA形成了缔合物。荧光猝灭光谱显示偏钒酸钠对牛血清白蛋白有较强的荧光猝灭作用，荧光猝灭机理符合静态机制。缔合物的稳定常数分别为：K_s=0.357×10⁴(25 ℃)，K_{s相似文献}   

镍(Ⅱ)、镉(Ⅱ)与去甲基斑蝥酸钠和咪唑配合物的结构、与DNA/BSA的作用及抗增殖活性

以2种配体去甲基斑蝥酸钠(Na₂DCA=7-氧杂二环[2.2.1]庚烷-2,3-二甲酸钠)和咪唑(IM),分别与镍(Ⅱ)和镉(Ⅱ)的醋酸盐通过溶液法合成了2种配合物[Ni(IM)(DCA)(H₂O)₂]·2H₂O(1),[Cd₂(IM)₄(DCA)₂]·2H₂O(2)。应用元素分析、热重分析、红外光谱及X-射线单晶衍射法对配合物的组成和结构进行了表征。配合物1与2的中心离子分别与咪唑的亚胺氮原子、去甲基斑蝥酸根的羧基氧原子和醚键氧原子配位,配位数均为6,分别为单核(1)和双核(2)配合物。通过紫外光谱法、荧光光谱法和粘度法研究了配合物与DNA的相互作用。结果表明,配合物能通过部分插入模式与DNA发生较强的结合作用(K_b:5.51×10³(1)、1.01×10³(2)L·mol^-1)。同时,利用荧光光谱法研究了配合物与牛血清白蛋白(BSA)的相互作用。配合物能与BSA发生强烈的相互作用(K_AM:1.91×10⁵(1)和6.17×10⁵(2)L·mol^-1),结合位点数均为1。测试了配合物对人肝癌细胞(SMMC₇₇₂₁)和人乳腺癌(MCF-7)的体外抗增殖活性。结果显示,配合物对不同癌细胞具有选择性抑制作用。镍配合物(1)对SMMC₇₇₂₁的抗癌活性较去甲基斑蝥酸钠有明显提高。     

邻菲咯啉乳酸镍配合物的合成与表征及其与牛血清白蛋白相互作用的荧光分析

利用溶液法合成了配合物[Ni(Hlact)2(phen)]·2H2O(1),并对该配合物进行了元素分析、红外光谱和X-射线单晶衍射表征。通过荧光光谱法研究了不同温度下配合物1与牛血清白蛋白相互作用时的荧光强度的变化,计算了在不同温度下,配合物1与牛血清白蛋白(BSA)的结合常数、结合位点数以及热力学函数,并进一步讨论了配合物1与BSA相互作用时的作用力类型和两者之间的距离。结果表明,配合物1对牛血清白蛋白的荧光猝灭为静态猝灭过程,它与牛血清白蛋白的相互作用有一个位点,结合常数的平均值5.06×105L·mol-1,作用距离为2.35 nm,相互作用力表现为氢键和范德华力。     

三种钴乙醇酸配合物与牛血清白蛋白相互作用的荧光分析

利用溶液法合成了3种钴乙醇酸配合物,并对配合物cis-[Co₂（Hgly）₄（2,2’-bpy）₂]（Hgly=glycolicacid,2,2’-bpy=2,2’-bipyridine）（3）进行了X-射线单晶衍射表征,结果表明：该配合物为三斜晶系,空间群为P2₁/c,a=1.0037（3）nm,b=2.0226（5）nm,c=1.6601（4）nm,β=119.942（13）°,V=2.9203（13）nm³。利用荧光光谱法分别研究了室温下这3种配合物与BSA相互作用的结果,并测定了不同温度下配合物2和3与牛血清白蛋白相互作用的荧光强度的变化,确定了配合物2和3对牛血清白蛋白的荧光淬灭方式均为静态淬灭;同时分析了这两种配合物与牛血清白蛋白相互作用时的结合常数、结合位点数以及热力学函数与温度变化之间的关系,进一步讨论了这两种配合物分别与BSA相互作用时的作用力类型。综合以上结果表明：当分别含有邻菲咯啉和2,2’-联吡啶配体的配合物与BSA相混合时,它们都能与BSA相互作用,且主要的作用力都是氢键和范德华力,但它们对蛋白质中色氨酸的构象或其周围环境的影响却是不同的。     

苯并咪唑衍生的单核钴（Ⅱ）和单核镍（Ⅱ）配合物与DNA和蛋白质的结合反应性及细胞毒活性研究

利用紫外吸收光谱、荧光光谱、圆二色光谱（CD）等各种光谱手段对比地研究了由苯并咪唑衍生的单核钴配合物[Co（EDTB）]²⁺（1）和单核镍配合物[Ni（EDTB）]²⁺（2）（这里EDTB为N,N,N’,N’-四（2-苯并咪唑甲基）-1,2-乙二胺）与小牛胸腺DNA（CT-DNA）和牛血清白蛋白（BSA）的相互作用。结果表明,在生理条件下,配合物1和2均能通过插入方式较强的与CT-DNA结合,诱导DNA构象的改变;且配合物1对DNA的结合能力略强于2,其结合常数分别为K_b（1）=3.23×10⁴L·mol^-1和K_b（2）=2.40×10⁴L·mol^-1。配合物与BSA相互作用的研究表明,1和2均能与BSA发生较强的相互作用,结合常数均处在10⁴~10⁵L·mol^-1;该结合引起了BSA微环境和构象发生变化,且使BSA内源荧光被淬灭,淬灭机理为静态淬灭。利用MTT法研究了配合物1和2对小鼠白血病细胞株P388和人非小细胞肺癌细胞株A-549的体外细胞毒活性,实验结果表明,配合物1和2对P388不敏感,对A-549在高浓度（10^-4~10^-5mol·L^-1）下表现出与顺铂相当的细胞毒活性。     

胡椒碱与牛血清白蛋白的作用及Cu2+、Fe3+影响的研究

采用荧光光谱及紫外光谱法研究了胡椒碱与牛血清白蛋白（bovine serum albumin,BSA）的相互作用。实验结果表明：胡椒碱与BSA形成基态复合物从而猝灭BSA的内源性荧光,猝灭原因主要为静态猝灭和非辐射能量转移作用。胡椒碱对BSA的猝灭速率常数Kq为7．31×10^12 L·mol^-1·s^-1（25℃）和7．20×10^12 L·mol^-1·s^-1（37℃）,胡椒碱与BSA的结合常数K为1．02×10^7 L·mol^-1（25℃）和1．11×10^7 L·mol^-1（37℃）,结合位点数n为1．45（25℃）和1．46（37℃）。根据Ftirster偶极-偶极非辐射能量转移理论问题得到结合距离r为3．28nm（25℃）和3．30nm（37℃）。通过热力学参数的计算,确定胡椒碱与牛血清白蛋白的相互作用是一个熵增加和吉布斯自由能降低的自发过程,主要作用力为疏水作用力。同步荧光光谱表明,胡椒碱与BSA的相互作用没有引起BSA构象的变化。讨论了共存金属离子Cu^2＋、Fe^3＋对胡椒碱与BSA相互作用的影响。     

邻菲咯啉合铜配合物与牛血清白蛋白的相互作用

利用荧光光谱法研究了两种配合物,[Cu（phen）（L-Phe）（H2O）]ClO4（1）（L-Phe为L-苯丙氨酸根）和[Cu（phen）（Gly）（H2O）]ClO4·2．5H2O（2）（Cly为甘氨酸根）,与牛血清白蛋白（BSA）的相互作用。结果表明,牛血清白蛋白的荧光强度随着配合物浓度的增大而逐渐降低,配合物（2）与BSA的结合常数大于配合物（1）与BSA的结合常数,牛血清白蛋白对配合物的结合位点数为1,荧光猝灭作用机理为静态猝灭．     

芥子碱与牛血清白蛋白的相互作用

利用荧光光谱法研究了新芥子碱与牛血清白蛋白(BSA)的相互作用,结果表明,新芥子碱对牛血清白蛋白的荧光有猝灭作用,且荧光光谱有较大的红移,其猝灭类型属于静态猝灭;根据Stern-Volmer荧光猝灭方程计算得到不同温度下的新芥子碱和BSA的结合常数和结合位点数;由实验计算得到该猝灭反应的热力学参数,表明新芥子碱与BSA之间相互作用以氢键和范德华力为主;根据能量转移理论求得新芥子碱与BSA的结合距离及能量转移率。     

乳酸钴配合物与牛血清蛋白相互作用的研究

合成和表征了系列乳酸钴配合物,测定二水二乳酸钴配合物的结构,配合物中乳酸的羟基和羧基配位键平均键长分别为0.206 0(2)nm和0.206 8(2)nm。当[Co(Hlact)2(H2O)2](2)或[Co(Hlact)2(phen)].2H2O(4)配合物与牛血清白蛋白(BSA=Bovine SerumAlbumin)相互作用后,红外光谱显示乳酸或邻菲咯啉的特征吸收消失,钴离子与BSA出现新的配位,初步推定乳酸或邻菲咯啉配体被BSA中的强配体所取代。     

Probing the Interaction Between a Surfactant–Cobalt(III) Complex and Bovine Serum Albumin

The mechanism of binding of the surfactant–cobalt(III) complex, cis-[Co(phen)₂(C₁₄H₂₉NH₂)Cl](ClO₄)₂⋅3H₂O (phen = 1,10-phenanthroline, C₁₄H₂₉NH₂ = tetradecylamine) with bovine serum albumin (BSA) was investigated by UV–vis absorption, circular dichroism (CD) and fluorescence spectroscopic techniques. The results of fluorescence titration revealed that the surfactant–cobalt(III) complex quenched the intrinsic fluorescence of BSA through a combination of static and dynamic quenching. The apparent binding constant (K _a) and number of binding sites (n) were calculated below and above the critical micelle concentration (CMC). The thermodynamic parameters determined by the van’t Hoff analysis of the constants (ΔH ^∘=14.87 kJ⋅mol⁻¹; ΔS ^∘=152.88 J⋅mol⁻¹⋅K⁻¹ below the CMC and 25.70 kJ⋅mol⁻¹ and 243.14 J⋅mol⁻¹⋅K⁻¹, respectively, above the CMC) clearly indicate that the binding is entropy-driven and enthalpically disfavored. Based on F?rster’s theory of non-radiation energy transfer, the binding distance, r, between donor (BSA) and the acceptor (surfactant–cobalt(III) complex) was evaluated. UV–vis, CD and synchronous fluorescence spectral results showed that the binding of the surfactant–cobalt(III) complex to BSA induced conformational changes in BSA.     

Direct electrochemical synthesis and characterization of cobalt and nickel complexes with 2-pyridinone and 2-pyridinemethanethiol-1-oxide

Summary The electrochemical oxidation of anodic metals (nickel and cobalt) in MeCN solutions of 2-pyridinone (HOpy) or 2-pyridine methanethiol-1-oxide (HPMTO) or its dimer, 2,2′-dithiodimethyldipyridine-1,1′-dioxide (DPMTO), gives the simple complexes [Ni(Opy)₂]·2H₂O, [Co(Opy)₂]·2H₂O, [Ni(PMTO)₂]·2H₂O and [Co(PMTO)₂]·3H₂O. When 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen) was added to the electrolytic phase, only three mixed complexes were obtained: [Ni(Opy)₂bipy]·H₂O, [Co·(Opy)₂phen]·H₂O and [Ni(Opy)₂phen]·5H₂O. The complexes were characterized by their elemental analyses, i.r. spectra and magnetic properties.     

Synthesis,spectral properties,in vitro α-glucosidase inhibitory activity and quantum chemical calculations of novel mixed-ligand M(II) complexes containing 1,10-phenanthroline

A series of mixed-ligand M(II) complexes containing 1,10-phenanthroline (phen) and 3-methylpyridine-2-carboxylic acid (3-mpaH) or 6-methylpyridine-2-carboxylic acid (6-mpaH), namely [Co(3-mpa)₂(phen)]·3H₂O ( 1 ), [Hg(6-mpa)₂(phen)]·2H₂O ( 2 ), [Mn(6-mpa)₂(phen)]·2H₂O ( 3 ), [Co(6-mpa)₂(phen)]·H₂O ( 4 ) and [Ni(6-mpa)₂(phen)]·H₂O ( 5 ), were synthesized for the first time. Among them, 1 was obtained as single crystals. The structural characterization for 1 was conducted using X-ray diffraction and that for 2 – 5 using mass spectrometry. The IC₅₀ values for α-glucosidase inhibition of 1 – 5 were obtained as 0.161 to >600 μM. The spectral properties were also investigated using Fourier transform infrared and UV–visible spectra. Furthermore, to investigate the geometrical parameters, spectral and electronic properties and second- and third-order nonlinear optical parameters for 1 – 5 , density functional calculations were applied.     

A new series of oxofluorovanadates (IV) of the type [VOF3(H2O)]−

Four salts of a new series of the type LH[VOF₃(H₂O)] (where L = pyridine,2,6,-lutidine, 2,2′-bipyridyl and 1,10-phenanthroline) have been isolated by crystallising solutions of the bases in aqueous hydrofluoric acid with VOSO₄·3H₂O. A dinuclear complex, pyH[(VO)₂F₅] and two nonelectrolytes, [VOF₂(bipy)] and [VOF₂(phen)] have also been prepared by the pyrolysis of the corresponding salts of [VOF₃(H₂O)]. The molecular conductances of dilute aqueous solutions of the salts are very high indicating appreciable decomposition, whereas the molecular conductances of [VOF₂(bipy)] and [VOF₂(phen)] in nitrobenzene are practically zero. The magnetic moments of the salts and the nonelectrolytes are almost equal to the spin-only value for one electron. The dinuclear complex pyH[(VO)₂F₅] is, however, much weakly paramagnetic (μ_eff = 1.33 BM). The i.r. spectra of all the complexes show very strong terminal VO bands between 980-940 cm^-1. The spectrum of pyH[(VO)₂F₅] gave no bands between 950-750 cm^-1 indicating the absence of bridging VO group.     

Synthesis,crystal structures,and fluorescence properties of (RS)-2-methylglutarato Zn(II), Cd(II) complexes

Reactions of fresh M(OH)₂ (M = Zn²⁺, Cd²⁺) precipitate and (RS)-2-methylglutaric acid (H₂MGL), 2,2′-bipyridine (bipy), or 1,10-phenanthroline (phen) in aqueous solution at 50°C afforded four new metal–organic complexes [Zn₂(bipy)₂(H₂O)₂(MGL)₂] (1), [Zn₂(phen)₂(H₂O)(MGL)₂] (2), [Cd(bipy)(H₂O)(MGL)] · 3H₂O (3), and [Cd(phen)(H₂O)(MGL)] · 2H₂O (4), which were characterized by single crystal X-ray diffraction, IR spectra, TG/DTA analysis as well as fluorescence spectra. In 1, the [Zn(bipy)(H₂O)]²⁺ moieties are linked by R- and S-2-methylglutarate anions to build up the centrosymmetric dinuclear [Zn₂(bipy)₂(H₂O)₂(MGL)₂] molecules. In 2, the 1-D ribbon-like chains [Zn₂(phen)₂(H₂O)(MGL)₂] _n can be visualized as from centrosymmetric dinuclear [Zn₂(phen)₂(H₂O)₂(MGL)₂] units sharing common aqua ligands. Both 3 and 4 exhibit 1-D chains resulting from [Cd(bipy)(H₂O)]²⁺ and [Cd(phen)(H₂O)]²⁺, respectively, bridged alternately by R- and S-2-methylglutarate anions in bis-chelating fashion. The intermolecular and interchain π···π stacking interactions form supramolecular assemblies in 1 and 1-D chains in 2–4 into 2-D layers. The hydrogen bonded lattice H₂O molecules are sandwiched between 2-D layers in 3 and 4. Fluorescence spectra of 1–4 exhibit LLCT π → π* transitions.     

Two novel coordination polymers [Sm2(Pzdc)3(H2O)]x · 2xH2O and [Nd2(Pzdc)3(H2O)]x · 2xH2O: Synthesis, structure, and photoluminescent properties

Coordination polymers, [Sm₂(Pzdc)₃(H₂O)] _x · 2xH₂O (I) and [Nd₂(Pzdc)₃(H₂O)] _x · 2xH₂O (II), were obtained by hydrothermal reactions with 2,3-pyrazinedicarboxylic acid (H₂Pzdc) and the salts nitrates, and characterized by single crystal X-ray structure, thermogravimetric analysis, element analysis and infrared spectroscopy. The X-ray crystal diffraction data indicates that two complexes crystal in a monoclinic system with the space group P2₁/c, of the three dimensional framework. The Pzdc ligand in the complexes I and II adopts tetradentate, hexadentate, and heptadentate bridging modes. The influences of coordination modes of the Pzdc ligand on the superstructural diversity is discussed. The photoluminescent data suggest that the ligands act as efficient “antennas” sensitizing the luminescence of the Sm³⁺ ion. Complex I exhibits strong fluorescent emission bands in the solid state at room temperature.     

Aggregates of complexes [Sc(H2O)4(NCS)2]+ and [Sc(H2O)2(NCS)4]? with 18-crown-6

The compounds [Sc(H₂O)₄(NCS)₂][Sc(H₂O)₂(NCS)₄] ·2(18C6) (I) and [Sc(H₂O)₄(NCS)₂][Sc(H₂O)₂(NCS)₄] · 3(18C6) · H₂O (II) were synthesized and studied by X-ray diffraction analysis. It was found that the cations in the structures of compounds I and II form sandwiches [Sc(H₂O)₄(NCS)₂] · 2(18C6). In the case of I, the sandwiches are united by the [Sc(H₂O)₂(NCS)₄]⁻ anions into chains, while in compound II, the sandwiches and infinite chains of [Sc(H₂O)₂(NCS)₄] · 18C6 · H₂O are bonded by van der Waals contacts only. Original Russian Text ? A.B. Ilyukhin, S.P. Petrosyants, 2007, published in Koordinatsionnaya Khimiya, 2007, Vol. 33, No. 4, pp. 275–281.     

Reactivity of the Re-NO centre: Proton induced oxidation of Re(NO)2+ to Re(NO)3+. Synthesis and characterisation of some Re(II) thiocyanato-halogenonitrosyl complexes

The Re(NO)²⁺ moiety as [Re(NO)(NCS)₃H₂O]⁻ or [Re(NO)(NCS)₂(L-L)H₂O]· [L-L = phen (1,10-phenanthroline) or bipy (2,2′-bipyridine)] undergoes proton-induced oxidation reaction with HX (X = Cl, Br) to produce a Re(NO)³⁺ moiety. The spectral and physico-chemical data suggest that the anionic complex is 5 coordinate and the neutral one is 6 coordinate with axial NO group and two NCS ligands intrans-equatorial positions. The complex, [Re(NO)(NCS)₂(phen)Br]·H₂O shows complicated magnetic behaviour which is discussed in the paper. The ESR spectrum of this compound shows typical rhenium hyperfines and <g>-tensor anisotropy compatible with the loss of axial symmetry. However, the spectrum of [Re(NO)(NCS)₂Br₂]⁻ quite reasonably shows axial symmetry, other features being grossly comparable to the L-L compounds. The anionic species and the neutral L-L complex show irreversible one-electron oxidation waves at different voltages. This may correspond to a conversion of Re(NO)³⁺ to Re(NO)⁴⁺ in both the cases. Interestingly enough, only the neutral complexes exhibit an irreversible reduction wave due probably to a conversion of Re(NO)³⁺ to Re(NO)²⁺.