带茂铁基团的茂钛配合物研究进展

综述了带有二茂铁基团的茂钛配合物分二茂铁单茂钛和二茂铁二茂钛配合物等几大类的结构和合成等在近年的研究进展。     

聚苯醚键联的二氯二茂钛的合成及催化性能的研究

以聚苯醚高分子为载体,采用“一锅法”合成了新的聚苯醚键联的二氯二茂钛衍生物。对合成的配合物进行了元素及光谱分析。研究了配合物对烯丙基苯类化合物异构化反应的催化性能,并讨论了不同条件对反应的影响。ESR 谱证实上述含钛高分子配合物所形成的钛氢配合物具有“位置分离效应”,主要处于非聚合的单分子态。     

葡萄糖酸及乳糖酸与二茂钛组装物的合成及其抗癌性研究

糖是除核酸和蛋自质之外另一类重要的生命物质,糖类化合物不仅可作为能量的来源,还可以成为功能分子的载体;许多有机金属化合物（如二氯二茂钛）都有不同程度的抗病毒,抗癌活性。将金属有机、金属配合物与生物分予糖或其衍生物组装一类新化合物一金属,糖组装物,研究表明优秀的糖组装物跟其单个化合物相比,所表现的活性可以提高至原来的10^5甚至10^7倍。文章以葡萄糖酸钠、乳糖酸、二氯二茂钛为原料合成两种糖／金属有机物-Cp2TiClC6H11O7、Cp2TiClC12H21O12,进行了结构鉴定和生物活性试验。     

多核茂钛配合物研究进展

茂钛配合物由于在催化烯烃聚合、有机合成以及抗癌活性等方面的重要作用而备受关注。尤其是多核茂钛配合物的重要性和独特性更是研究的热点之一。现将多核茂钛配合物分为链状、环状和离子型等几大类,分别对其结构、合成、反应条件和化学反应等在近年来的研究进展进行了综述。     

新型含硫杂环双(β-二酮)钛(Ⅳ)配合物的合成

鉴于舍硫杂环基团和双(β-二酮)钛(Ⅳ)配合物均具有良好的药理活性,设计合成了两个新型含硫杂环双(β-二酮)钛配合物(Ⅱa,Ⅱb),并通过元素分析、红外光谱、.1HNMR、MS等手段对其结构进行了表征.     

二氯二茂钛与取代苯甲醛肟的反应

二氯二茂钛与取代苯甲醛肟钠在二氯甲烷中反应，生成二茂钛单肟衍生物Ｃｐ２ＴｉＣｌ（ＯＮ＝ＣＨＡｒ），其中Ａｒ为邻硝基苯基，间硝基苯基，对硝基苯基，邻氯苯基，间氯苯基，３，４－二氯苯基，间甲氧基苯基，对甲氧基苯基，２，４－二甲氧基苯基和３，４－亚甲基二氧苯基。所有这些新化合物在干燥空气中稳定，对潮湿空气敏感。经元素分析外，核磁氢谱表征，确认了其结构。     

有水条件下合成茂钛/锆配合物的研究进展

茂钛/锆化合物在催化烯烃聚合、氢化异构化、有机合成、抗癌活性及潜在的超强酸催化性能等方面均表现出了重要的应用前景,含水条件合成茂钛/锆配合物为绿色合成该类化合物提供了可行的途径。该文综述了有水条件下合成茂钛/锆配合物的各种方法。     

一种新的糖/金属组装物的合成

许多有机金属化合物具有抗病毒,抗癌功能,但是它们水溶性差,使人体对药物的吸收就受到影响,无法产生应有的药效.将糖基引入到有机金属化合物及其衍生物中.形成双药效基团,可以提高药物的溶解性,提高药物的吸收效率.文章以乳糖酸、氨基乙酸、二氯二茂钛为原料合成一种新的金属/糖组装物-乳糖酸二茂钛酯,并对其结构进行了表征.     

二氯二茂钛用于SBS加氢的研究

选用二氯二茂钛(Cp2TiCl2)作为丁苯嵌段共聚物加氢催化剂,用活性胶分别进行了催化剂用量、压力、温度对加氢效果的影响研究,得到了较好的加氢条件。用二氯二茂钛作加氢催化剂、催化剂用量为(0.2~0.4)mmol/100 g聚合物时,二烯烃段加氢度可大于98%。     

蒽镁作为活性中间体合成二氯二茂钛

报道了通过蒽镁活性中间体合成二氯二茂钛，该方法具有反应条件温和，操作简便，易于分离，产率高等优点。     

Effect of Bulk Doping on the Electrical Conductivity of Selected Metallocene Polyamines

The conductivity of the polyamine derived from titanocene dichloride and 2-nitro-1,4-phenylenediamine increases to 10¹ to 10³ fold when doped with iodine. Larger increases are found for the analogous polyamines except derived from zirconocene dichloride (increased 10³–10⁴ fold) and hafnocene dichloride (10⁵–10⁶ fold) and for certain other diamines. The conductivity of the product of titanocene dichloride and N-methyl-1,4-phenylenediamine increased 10⁵ fold when doped. By comparison, conductivity increased only tenfold for the product from titanocene dichloride and chloro-1,4-phenylenediamine and less for the titanocene product with 1,4-phenylenediamine and methoxy-1,4-phenylenediamine and none for the product from dibutyltin dichloride and 2-nitro-1,4-phenylenediamine. Conductivity did not appreciably change when samples were exposed to the atmosphere for 21 h. MALDI MS and IR results are consistent with the formation of C–I compounds for doped materials.     

Heterogeneous catalyst mixtures for the polymerization of ethylene

Heterogeneous cocatalysts, catalysts, and catalyst mixtures for the polymerization of ethylene were prepared applying “fumed silica” and mesoporous MCM-41 support materials and zirconocene dichloride, titanocene dichloride, and a bis(arylimino)pyridine iron complex as catalyst precursors. The catalyst mixtures produced polyethylenes which exhibit the properties of two single polymers. Polyethylenes with the desired bimodal molecular weight distributions could be obtained with a series of ternary Zr/Ti/Fe catalysts. The ability of the zirconium and titanium species to copolymerize short-chain 1-olefins produced by the iron centers (“in situ” copolymerization) is useful for the production of copolymers from only one monomer (ethylene).     

二氯二茂钛二甲硫氨酸与DNA相互作用的电化学及紫外-可见光谱研究

用循环伏安法考察了二茂钛二甲硫氨酸配合物(TMC)与DNA在pH=3.0的KCl水溶液中相互作用的电化学行为。TMC在玻碳电极上分别于-412 mV和-528 mV(υs.SCE)有一个氧化峰和相应的还原峰。加入DNA后,TMC的式量电位负移5 mV,峰电流增加,电化学参数(α和ks)改变。结果表明:在该条件下,TMC与DNA之间通过静电作用,形成了一种具有电活性的复合物,且TMC与DNA之间的结合位点数n和结合常数K分别为4.36和2.74×1016。结合紫外-可见光谱法测定结果,加入DNA后TMC的紫外-可见光谱在393 nm处呈现增色效应,进一步确证了TMC与DNA之间主要以静电作用为主。     

二氯二茂钛的合成及其对SBS加氢催化性能的研究

以二聚环戊二烯(dicyclopentadiene)为原料,将其裂解得到环戊二烯(cyclopentadiene,Cp);在二乙胺存在的条件下将其与四氯化钛反应,合成了二氯二茂钛(titanocene dichloride,TDC),并以合成的目标产物作为丁苯嵌段共聚物(SBS)加氢催化剂,对其催化性能进行了研究。当加氢反应温度为70℃,压力为2.0MPa,催化剂用量为0.4mmol/100g聚合物时,SBS中加氢度达到94.2%。说明目标产物具有良好的催化性能。     

Transesterification of dimethyl carbonate and phenol to diphenyl carbonate catalyzed by titanocene complexes

Some titanocene complexes were used as catalysts for the transesterification of phenol and dimethyl carbonate to diphenyl carbonate. It was found that titanocene catalysts modified by various substituents would strongly influence the steric and electronic properties of the catalytic centers, the stability of the transition states and their catalytic behaviors. The yields of methyl phenyl carbonate and diphenyl carbonate might be improved by designing the structure of the titanocene complexes. When the substituent was smaller and more electron withdrawing, or the substituent could make the transition state stabler, the reaction would go on with better results.     

Electrosynthesis and properties of poly(3,4-ethylenedioxythiophene) films functionalized with titanocene dichloride complex

Synthesis of a titanocene dichloride derivative functionalized with 3,4-etylenedioxythiophene group, Tc1EDOT (Cl₂TiCpC₅H₄(CH₂) (3,4-ethylenedioxythiophene)) has been described. Redox behavior of the monomer in tetrahydrofuran (THF), dichloromethane (DCM) and acetonitrile (AN) at different scan rates has been discussed in terms of different ability of these solvents to coordination with the reduced titanocene (Tc) complex and the solvation of Cl⁻ anions. Electrooxidation of Tc1EDOT to get a conducting polymer film with immobilized titanocene dichloride centers and electrochemical properties of its polymer matrix in background acetonitrile solution have been compared with those of non-substituted PEDOT and PEDOT-methanol derivative (PEDOTMet), to elucidate the effect of substituents both on polymerization and redox potentials of the matrix. STM and AFM images of p(Tc1EDOT) films obtained with potentiodynamic and potentiostatic regimes are compared to illustrate that the films deposited at constant potential are better ordered and more compact than those obtained by cyclic voltammetry. A comparison of the cyclic voltammograms of p(Tc1EDOT) and poly(titanocene-propyl-pyrrole) (p(Tc3Py)) films in 0.1 TBAPF₆ in THF has shown that the electroactivity of the polymer matrix of p(Tc1EDOT) is extended to more negative potentials in comparison to that of p(Tc3Py). This results in the anodic shift of redox potential of Tc centers immobilized in p(Tc1EDOT) film with respect to that of the centers fixed in p(Tc3Py).     

Polymerization of methyl methacrylate by metallocenes

Attempts at polymerizing methacrylate using metallocenes are reported. Polymerization is successful using ferrocene in a ketone solution, but not in benzene or without a solvent. Ketones are effective in the order: methyl ethyl ketone < cyclohexanone < cycloheptanone. Carbon tetrachloride has an accelerative effect on the polymerization in benzene and methyl ethyl ketone solutions, but no effect in cyclohexanone solution. Some binary systems, which consist of ferrocene and higher valence compounds such as cobalt trisacetylacetonate, are effective redox initiators. Cobaltocene polymerizes methyl methacrylate in the presence of carbon tetrachloride; zirconocene dichloride induces polymerization of methyl methacrylate in a cyclohexanone solution; whereas neither nickelocene nor titanocene dichloride are effective. Styrene and acrylonitrile were not polymerized by the metallocenes examined.     

Mass Spectrometric Evaluation of β-Cyclodextrins as Potential Hosts for Titanocene Dichloride

Bent metallocene dichlorides (Cp₂MCl₂, M = Ti, Mo, Nb, …) have found interest as anti-cancer drugs in order to overcome the drawbacks associated with platinum-based therapeutics. However, they suffer from poor hydrolytic stability at physiological pH. A promising approach to improve their hydrolytic stability is the formation of host-guest complexes with macrocyclic structures, such as cyclodextrins. In this work, we utilized nanoelectrospray ionization tandem mass spectrometry to probe the interaction of titanocene dichloride with β-cyclodextrin. Unlike the non-covalent binding of phenylalanine and oxaliplatin to β-cyclodextrin, the mixture of titanocene and β-cyclodextrin led to signals assigned as [βCD + Cp₂Ti–H]⁺, indicating a covalent character of the interaction. This finding is supported by titanated cyclodextrin fragment ions occurring from collisional activation. Employing di- and trimethylated β-cyclodextrins as hosts enabled the elucidation of the influence of the cyclodextrin hydroxy groups on the interaction with guest structures. Masking of the hydroxy groups was found to impair the covalent interaction and enabling the encapsulation of the guest structure within the hydrophobic cavity of the cyclodextrin. Findings are further supported by breakdown curves obtained by gas-phase dissociation of the various complexes.