双核钌(II)多吡啶配合物与酵母RNA的相互作用研究

用紫外-可见吸收光谱和荧光光谱滴定、稳态荧光淬灭和反向盐滴定实验研究了双核钌(II)配合物[(bpy)₂Ru(ebipcH₂)Ru(bpy)₂](ClO₄)₄ {bpy＝2,2'-联吡啶; ebipcH₂＝N-乙基-4,7-二(咪唑-[4,5-f]-(1,10-邻菲啰啉)-2-基)咔唑}与酵母RNA的相互作用. 结果表明该双核配合物以插入方式与酵母RNA作用, 在生理盐浓度下(≈150 mmol/L NaCl)该配合物与RNA的相互作用明显强于DNA.     

噻吩基钌配合物与酵母RNA的相互作用研究

通过紫外-可见吸收光谱和荧光光谱滴定、稳态荧光猝灭以及盐效应实验研究了噻吩基钌配合物[Ru(bpy)2(Htip)]Cl2(1)、[Ru(Htip)2(dppz)]Cl2(2)、[Ru(Htip)3]Cl2(3)和[Ru2(bpy)4(H2bipt)]Cl4(4){bpy=2,2'-联吡啶;Htip=2-噻吩咪唑[4,5-f][1,10]邻菲咯啉;H2bipt=2,5-二(2-咪唑[4,5-f][1,10]邻菲咯啉)噻吩;dppz=二吡啶并[3,2-a:2',3'-c]吩嗪}与酵母RNA(yeast-RNA)的相互作用,并比较了该类配合物与yeast-RNA和小牛胸腺DNA(ct-DNA)的键合性质。结果表明,该类噻吩基钌配合物是较强的RNA嵌入试剂,其中配合物2和3的RNA键合强度大于其DNA键合强度;此系列配合物在低盐和高盐浓度时均能与RNA较强地结合,即使在100 mmol/L Na Cl条件下仍具有较大的RNA键合常数;配合物1与RNA键合时荧光强度下降,配合物2在水溶液中以及与RNA键合时几乎无荧光,而它们与DNA作用时荧光强度明显增大,显示出良好的区分RNA和DNA的荧光特性。     

新型双核配合物的形成及荧光性质研究

利用光谱学方法研究了[Ru(bpy)2TPPHZ]2+(TPPHZ=四吡啶[3,2-a: 2',3'-c: 3",2"-h: 2'",3'"-j]吩嗪)和[Ru(bpy)2ODHIP]2+(ODHIP=3,4-二羟基-咪唑并[4,5-f][1,10]邻菲咯啉)与Ni2+的配位情况及配位后的荧光性质变化, 探讨了配合物与Ni2+配位形成双核配合物后与DNA的作用机制变化. 结果表明, [Ru(bpy)2TPPHZ]2+和[Ru(bpy)2ODHIP]2+均可与Ni2+配位, 形成双核配合物[Ru(bpy)2(TPPHZ)Ni]4+和[Ru(bpy)2(ODHIP)Ni]4+, 配合物的荧光强度随着Ni2+浓度的增加而减弱. 与DNA作用后, 配合物仍可与Ni2+配位形成双核配合物, [Ru(bpy)2(TPPHZ)Ni]4+的荧光几乎完全消失, 同时配合物与DNA保持插入模式作用, 而配合物[Ru(bpy)2(ODHIP)Ni]4+与DNA的作用则由沟面结合改为插入结合, 同时配合物的荧光减弱.     

吲哚咪唑基钌(Ⅱ)联吡啶配合物与酵母RNA的相互作用

通过紫外-可见光谱和荧光光谱滴定、稳态荧光猝灭和溴化乙啶竞争键合实验研究了Ru(Ⅱ)配合物[Ru(bpy)(H₂iip)₂](ClO₄)₂{bpy=2,2′-联吡啶, H₂iip=2-(吲哚-3-基)-咪唑[4,5-f][1,10]-邻菲罗啉}的酵母RNA键合性质. 结果表明, 二者键合模式为嵌入键合, 其键合常数为7.09×10⁶ L/mol, 比小牛胸腺DNA的键合常数大, 且比同类配合物[Ru(bpy)₂(H₂iip)](ClO₄)₂的酵母RNA键合常数大.     

钌（Ⅱ）多吡啶配合物的合成、荧光性质及与脱氧核糖核酸DNA的作用机制研究

设计合成含多个配位中心的多吡啶配体ODCIP(3,4-二氯基苯并咪唑并[4,5-f][1,10]邻菲咯啉)及其钌(Ⅱ)多吡啶配合物[Ru(bpy)2ODCIP]2 .运用元素分析、红外光谱、核磁谱和质谱对配体及配合物进行结构表征.利用紫外吸收光谱、荧光光谱和粘度法研究了[Ru(bpy)2ODCIP]2 与DNA(脱氧核糖核酸)的作用机制、与Co2 配位后与DNA的作用机制及其荧光变化情况.结果表明[Ru(bpy)2ODCIP]2 与DNA通过部分插入模式作用,[Ru(bpy)2ODCIP]2 与Co2 配位形成的双核配合物[Ru(bpy)2(ODCIP)Co]4 也能与DNA插入结合.进一步利用稳态荧光发射光谱、荧光淬灭实验等方法研究了单核配合物[Ru(bpy)2ODCIP]2 和双核配合物[Ru(bpy)2(ODCIP)Co]4 的荧光性质.     

钌(II)多吡啶配合物的合成、荧光性质及与脱氧核糖核酸DNA的 作用机制研究

设计合成含多个配位中心的多吡啶配体ODCIP (3,4-二氯基苯并咪唑并[4,5-f][1,10]邻菲咯啉)及其钌(II)多吡啶配合物[Ru(bpy)2ODCIP]2＋. 运用元素分析、红外光谱、核磁谱和质谱对配体及配合物进行结构表征. 利用紫外吸收光谱、荧光光谱和粘度法研究了[Ru(bpy)2ODCIP]2＋与DNA(脱氧核糖核酸)的作用机制、与Co2＋配位后与DNA的作用机制及其荧光变化情况. 结果表明[Ru(bpy)2ODCIP]2＋与DNA通过部分插入模式作用, [Ru(bpy)2ODCIP]2＋与Co2＋配位形成的双核配合物[Ru(bpy)2(ODCIP)Co]4＋也能与DNA插入结合. 进一步利用稳态荧光发射光谱、荧光淬灭实验等方法研究了单核配合物[Ru(bpy)2ODCIP]2＋和双核配合物[Ru(bpy)2(ODCIP)Co]4＋的荧光性质.     

一个新型钌(Ⅱ)配合物对F~-的双重光谱识别

采用紫外-可见光谱和荧光光谱滴定方法研究了钌(Ⅱ)配合物[Ru(bpy)(H2iip)2](ClO4)2[bpy=2,2'-联吡啶,H2iip=2-吲哚基-咪唑并[4,5-f][1,10]-邻菲罗啉]在DMSO溶液中对卤素离子的识别性质.结果表明该配合物能比色和荧光双重光谱高选择性识别F-.     

手性双核钌(Ⅱ)配合物与DNA的相互作用研究

本文合成了1对手性双核钌(Ⅱ)配合物ΔΔ-和ΛΛ-[(bpy)₂Ru(mbpibH₂)Ru(bpy)₂](ClO₄)₄(bpy=2,2′-联吡啶,mbpibH₂=1,3-二(咪唑并[4,5-f][1,10-邻菲咯啉])苯)。通过元素分析、质谱、核磁共振、CD光谱对这两个化合物进行了结构表征。采用循环伏安法对配合物的电化学性质进行了分析。利用紫外-可见吸收光谱滴定、荧光光谱滴定     

钌配合物[Ru(bpy)2(PNT)]2+的合成、表征及与DNA相互作用研究

以cis-Ru(bpy)2Cl2·2H2O与PNT为原料合成钌(Ⅱ)多吡啶配合物[Ru(bpy)2(PNT)]2+(bpy=2,2’-联吡啶, PNT=2-[4’-(5-四唑基)苯基]咪唑-[4,5-f][1,10]邻菲咯啉), 通过元素分析、质谱和核磁共振波谱对该化合物进行了结构表征. 利用紫外-可见吸收光谱、荧光光谱、热变性和黏度实验研究了配合物与CT-DNA的相互作用, 实验结果表明, 该配合物以部分插入模式与DNA结合.     

一个新型钌(II)配合物对F－的双重光谱识别

采用紫外-可见光谱和荧光光谱滴定方法研究了钌(II)配合物[Ru(bpy)(H2iip)2](ClO4)2 [bpy＝2,2’-联吡啶, H2iip＝2-吲哚基-咪唑并[4,5-f][1,10]-邻菲罗啉]在DMSO溶液中对卤素离子的识别性质. 结果表明该配合物能比色和荧光双重光谱高选择性识别F－.     

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%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.