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.     

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.     

钌多吡啶配合物与DNA作用及抗肿瘤活性

应用电子吸收光谱、荧光光谱和粘度测定等方法研究钌多吡啶配合物[Ru(phen)2(Hecip)]2(phen=1,10-邻菲啰啉,Hecip=2(9-乙基-9H-咔唑-3-基)-1H-咪唑并[4,5-f][1,10]菲啰啉)与DNA相互作用。结果表明配合物与DNA键合计量比为2∶1,键合常数超过105mol-1.L,配合物以插入方式与DNA结合。运用琼脂糖凝胶电泳实验研究配合物诱导pBR322DNA断裂及断裂机理。体外抗肿瘤活性结果表明配合物能有效抑制肿瘤细胞增殖,进一步研究表明配合物可以将细胞周期阻滞在S期。     

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.     

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.     

新型2-取代苯基-1H-咪唑[4,5-f][1,10]邻菲啰啉基Ru(II)配合物的光电性质

为获取具有活性官能团的接枝型、高性能荧光传感配合物,合成了2-(4-氨基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-NH2)、2-(4-羟基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-OH)、2-(4-羧基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-COOH)和2-(4-硝基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-NO2)四种配体,借助紫外-可见(UV-Vis)吸收光谱、荧光(PL)光谱、循环伏安法(CV)和含时密度泛函理论(TD-DFT)对上述四种配体与过渡金属元素钌(Ru)所形成的配合物的光电性能进行研究.结果表明:四种配合物均在可见光区域有较强吸收,发光范围覆盖绿色到红色光波段.在极性溶剂N,N-二甲基甲酰胺(DMF)中,以2-(4-氨基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉为配体所构建的钌配合物([Ru(CImPB-NH2)(bpy)2]2+的荧光量子产率(Φ)较不含咪唑环的5-氨基邻菲啰啉合钌([Ru(phen-NH2)(bpy)2]2+)的提高了67%,以2-(4-羧基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉所构建的钌配合物([Ru(CImPB-COOH)(bpy)2]2+)的Φ可达29.8%,是[Ru(phen-NH2)(bpy)2]2+的18倍.理论计算表明:配体中取代苯环、咪唑环和邻菲啰啉的稠环共平面,形成共价大π体系,其有效共轭长度较邻菲啰啉母体有显著增加,配合物是以Ru为中心的近似八面体构型,理论计算的电子吸收光谱和跃迁性质与实验结果相一致.上述研究有可能为接枝型、高性能荧光传感配合物的设计和筛选提供实验依据.     

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-.     

方波伏安法研究[Ru（bpy）2dppz]2+与DNA的相互作用

合成了含有嵌入配体二吡啶并[3,2-a:2′,3′-c]-吩嗪(dppz)的钌配合物二联吡啶二吡啶并[3,2-a;2′,3′-c]吩嗪钌([Ru(bpy)2dppz]2+),并对其结构和物理化学性质进行了表征。采用方波伏安法研究了[Ru(bpy)2dppz]2+与天然双链小牛胸腺DNA的相互作用,实验结果表明,[Ru(bpy)2dppz]2+配合物的嵌入配体会嵌入DNA的碱基对中,与DNA结合形成体积较大的"金属配合物-DNA"联合体,该联合体在电解质溶液中扩散速度较慢,导致溶液中游离的钌配合物分子减少,峰电流信号降低。计算得到[Ru(bpy)2dppz]2+与DNA的结合常数Ka=1.7×105 L/mol,结合位点n=0.84。     

[Ru(bpy)_2tpphz]~(2+)与Zn~(2+)形成的双核配合物的荧光性质研究

近年来,钌多吡啶配合物与DNA的作用得到了比较广泛的研究,并且发展了一系列具有特定功能的钌配合物犤1犦。如传统的DNA分子光开关犤Ru(bpy)2dppz犦2+和犤Ru(phen)2dppz犦2+犤2,3犦(bpy=2,2'-联吡啶,phen=1,10-菲咯啉,dppz=二吡啶犤3,2-a:2',3'-c犦吩嗪)。这些配合物与DNA具有较强的结合力,在水溶液中几乎不发光,但在DNA存在下则有强烈荧光发出。这是由于配合物插入DNA的碱基对之后,保护了dppz的吡嗪环上的N原子,使其免受水分子的进攻从而导致配合物荧光的恢复。但是对于大多数的多吡啶钌配合物来讲,由于其自身较强的背景荧光或与DN…     

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.     

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.     

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.     

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.