酰胺型开链冠醚类稀土配合物的合成及其与DNA的作用研究

以2,3-二羟基萘为母体,以稀土元素为中心离子,与苦味酸盐(pic)反应合成了3个末端基不同的酰胺型开链冠醚类稀土配合物。用红外吸收光谱、元素分析、摩尔电导率、差热-热重分析等方法对配体和配合物的组成和结构进行了表征分析。通过紫外光谱、荧光光谱、黏度和循环伏安法对配合物的荧光性质及与DNA的作用方式进行了研究。结果表明:该系列配合物的组成为RE(pic)3L(L1=C26H22N2O4,L2=C30H30N2O4,L3=C28H26N2O4;RE=Eu(Ⅲ),Tb(Ⅲ),Ce(Ⅲ),Y(Ⅲ))。Eu(Ⅲ)配合物荧光强度较强,Tb(Ⅲ)配合物次之,该类配体对Eu3+的敏化效果强于对Tb3+的。配合物与DNA的作用模式均为插入式,且Eu(pic)3L3配合物与DNA的键合作用最强。     

C3对称性含膦三足体衍生物及其稀土配合物的合成以及与DNA相互作用的研究

本文设计合成了一种新的C3对称性含膦三足体衍生物N’,N’’,N’’’-三（亚磷酸三乙酯）缩氨三乙酸（L=N’,N’’,N’’’-三（亚磷酸三乙酯）缩氨三乙酸）及其Eu(Ⅲ)配合物。用1HNMR、13CNMR、红外光谱、元素分析、差热-热重及紫外光谱对其组成和结构进行分析和表征。结果表明,三足体衍生物与稀土苦味酸盐(Eu(pic)3?6H2O形成了1:1型配合物Eu(pic)3L。综合运用紫外-可见吸收光谱法、荧光光谱法和循环伏安法研究了Eu(pic)3 L与小牛胸腺DNA之间的结合模式。通过紫外、EB探针及循环伏安得出了配合物Eu(pic)3L与DNA之间以嵌插形式发生相互作用。将该配合物作为杂交探针,对其在DNA电化学传感器方面的应用进行了探讨。结果发现,该配合物在修饰单链DNA的电极检测作用下,无明显的电化学信号响应。而当将其用于检测杂交双链DNA时,出现了明显信号,并且该配合物的DNA传感器对互补序列、错配序列及非互补序列都有良好的选择作用。     

Eu~(3+)和Tb~(3+)冠醚配合物的合成、荧光性质及与DNA作用研究

合成了含联萘骨架的酰胺型开链冠醚配体及稀土苦味酸盐配合物RE(pic)3L[L=N,N-乙基,苯基-N’,N’-二苯基-1,1’-联萘-2,2’-二(氧杂乙酰胺),RE=Eu3+,Tb3+],通过元素分析、IR、TG-DTA和摩尔电导率对配合物进行组成和结构推测。荧光光谱表明:Eu3+配合物的荧光强度远大于Tb3+配合物,说明配体L的三重态能级与Eu3+的激发态能级匹配较好。通过光谱法和粘度法研究了配合物与DNA的作用方式为插入作用,求出了Eu3+,Tb3+配合物与DNA的结合常数分别为4.072×104L.mol-1,8.780×103L.mol-1,证明配合物与DNA的作用大小是Eu3+(pic)3LTb3+(pic)3L.     

C3对称性含膦三足体衍生物及其Eu(III)配合物的合成以及与DNA相互作用的研究

设计合成了一种新的C3对称性含膦三足体衍生物N',N″,N-三(亚磷酸三乙酯)缩氨三乙酸(L)及其Eu(Ⅲ)配合物。用1H NMR、13C NMR、红外光谱、元素分析、差热-热重及紫外光谱对其组成和结构进行分析和表征。结果表明,三足体衍生物与稀土苦味酸盐(Eu(pic)3·6H2O)形成了1∶1配合物Eu(pic)3L。综合运用紫外-可见吸收光谱法、荧光光谱法和循环伏安法研究了Eu(pic)3L与小牛胸腺DNA之间的结合模式,结果表明,配合物Eu(pic)3L与DNA之间以嵌插形式发生相互作用。将该配合物作为杂交探针,对其在DNA电化学传感器方面的应用进行了探讨。结果发现,该配合物在修饰单链DNA的电极检测作用下,无明显的电化学信号响应,而当将其用于检测杂交双链DNA时,出现了明显信号,并且该配合物的DNA传感器对互补序列、错配序列及非互补序列都有良好的选择作用。     

2,2'-联吡啶In(Ⅲ)配合物与DNA作用的电化学研究

应用循环伏安法、微分脉冲伏安法和交流阻抗法研究了配合物In(bpy)Cl3.H2O与DNA在Tris-HCl缓冲溶液(pH=7.2)中的相互作用.结果表明:配合物中心In(Ⅲ)离子的循环伏安曲线上呈现一对准可逆的氧化还原波,DNA与配合物作用后,配位中心离子的氧化还原峰电流明显降低,扩散系数减小,电化学反应阻抗增大,式量电位负移,表明该配合物与DNA的作用方式为静电结合.     

2，2′-联吡啶In（Ⅲ）配合物与DNA作用的电化学研究

应用循环伏安法、微分脉冲伏安法和交流阻抗法研究了配合物In(bpy)Cl3·H2O与DNA在Tris-HCl缓冲溶液(pH=7.2)中的相互作用.结果表明配合物中心In(Ⅲ)离子的循环伏安曲线上呈现一对准可逆的氧化还原波,DNA与配合物作用后,配位中心离子的氧化还原峰电流明显降低,扩散系数减小,电化学反应阻抗增大,式量电位负移,表明该配合物与DNA的作用方式为静电结合.     

C3对称性含膦三足体衍生物及其Eu(Ⅲ)配合物的合成以及与DNA相互作用的研究

设计合成了一种新的C3对称性含膦三足体衍生物N',N',N'-三(亚磷酸三乙酯)缩氨三乙酸(L)及其Eu(Ⅲ)配合物.用1H NMR、13C NMR、红外光谱、元素分析、差热-热重及紫外光谱对其组成和结构进行分析和表征.结果表明,三足体衍生物与稀土苦味酸盐(Eu(pic)3·6H2O)形成了1:1配合物Eu(pic)3L.综合运用紫外-可见吸收光谱法、荧光光谱法和循环伏安法研究了Eu(pic)3L与小牛胸腺DNA之间的结合模式,结果表明,配合物Eu(pic)3L与DNA之间以嵌插形式发生相互作用.将该配合物作为杂交探针,对其在DNA电化学传感器方面的应用进行了探讨.结果发现,该配合物在修饰单链DNA的电极检测作用下,无明显的电化学信号响应,而当将其用于检测杂交双链DNA时,出现了明显信号,并且该配合物的DNA传感器对互补序列、错配序列及非互补序列都有良好的选择作用.     

双(N-苄基)-2,7-萘-二(氧杂乙酰胺)稀土配合物的合成、表征、荧光性及其与DNA的作用

合成了2,7-二(苄胺酰乙氧基)萘(L)与稀土(RE:Y,La,Eu,Tb)苦味酸盐(pic)的配合物[RE(pic)3L2],用1H NMR、红外光谱、元素分析和摩尔电导表征了它们的结构、组成及性质。在pH=7.20的Tris-HCl缓冲溶液中用光谱法、伏安法和粘度法,测定4种配合物均以插入方式与ct-DNA发生配合作用,其作用强度为:La(Ⅲ)>Tb(Ⅲ)>Y(Ⅲ)>Eu(Ⅲ)。     

铬(Ⅵ)-谷胱甘肽配合物诱导小牛胸腺DNA变性的新表征方法

本文采用电化学方法对铬(Ⅵ)-谷胱甘肽(GSH)配合物诱导DNA变性进行表征,同时运用原子力显微镜(AFM)对DNA损伤变性过程进行可视化探测.结果表明:在pH=5.6的HAc-NaAc缓冲溶液中,DNA溶液中加入Cr(Ⅵ)-GSH配合物后进行循环伏安扫描,+0.20 V和0.00 V(vs SCE)处出现一对新的氧化还原峰,该氧化还原峰随Cr(Ⅵ)-GSH配合物浓度增加峰电流上升.DNA热变性和表面活性剂SDS变性实验进一步证明了该峰为DNA变性后的氧化还原峰,且变性DNA的峰信号在修饰电极上比裸金电极上更为灵敏.电化学动力学表明在30 min内配合物诱导DNA变性的程度随时间的上升而增加,并通过AFM观察了配合物作用下DNA断链的过程.     

N_3非对称配体、稀土配合物的合成及其在DNA传感器中的应用

合成具有三脚架形结构的配体L及其稀土配合物。用元素分析、红外光谱、核磁共振波谱、热分析、紫外吸收光谱、荧光光谱等方法对L及其配合物的结构进行表证,用光谱法和电化学法分析配合物与BSA,DNA之间的相互作用,并考查其作为杂交探针在DNA传感器方面的应用。结果表明,每1个L中C=O,P=O,P-O上O均可与稀土离子Eu~(3+),Y~(3+)配位,L与苦味酸配体以1∶1配位,化学式为RE(pic)_3L·3H_2O (RE=Eu,Y); Eu(Ⅲ)配合物对BSA内源荧光以静态方式淬灭,能量为非辐射转移,两者之间主要存在氢键和范德华力; Eu(Ⅲ)配合物与ct-DNA之间以嵌插作用结合,且在实验范围内有电化学活性; Eu(Ⅲ)配合物可以识别电极上的杂交过程,对互补、非互补、错配序列有较好的选择性。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.