Cu（Ⅱ）—正胺络合物共价性的ESR研究

本文研究了乙胺等四种正胺配体与Cu(ClO_4)_2的配位络合物溶液的低温(77K)ESR谱。用超精细耦合常数和g值计算了σ键强度以及配位场分裂能次序。结果表明:σ键强度随着配位胺分子碳链增长而增强,至正戊胺配位络合物开始减弱;在这些Cu(Ⅱ)-正胺络合物中氨基以与氨不同的键性和Cu(Ⅱ)离子键合。     

双(二吡啶胺)配体的二维和三维超分子配位聚合物的合成与晶体结构

从含4,4'-二吡啶胺结构单元的双(二吡啶胺) 桥联配体出发,采用溶剂热法合成了两个结构新颖的配位聚合物：[CdL1Br2]n?7.5nH2O (L1 = N,N,N′,N′-四(4-吡啶)-1,4-苯二胺) (1)和[Cu2L2(μ1,1,3-SCN)2]n?nMeOH (L2 = N,N-二(2-吡啶)-N',N'-二(4-吡啶)-1,4-苯二胺) (2),对它们进行了元素分析、红外光谱等表征,并用X-射线单晶衍射测定了其晶体结构。单晶测试结果显示,配合物1中配体L1的四个吡啶N原子均参与配位,桥联了4个Cd原子,每个Cd原子与四个吡啶 N 原子和两个溴配位,形成六配位的八面体构型。通过这些配位作用,最终形成包含 Kagome 结构的三维超分子网络。配合物2 是由一维柱状 {Cu(SCN)}n 链通过 L2 桥联生成的二维结构。有趣的是,L2中具有螯合能力的2,2'-二吡啶胺单元并未参与配位,只有4,4'-二吡啶胺单元中的两个吡啶N原子分别与一个 Cu(I) 配位,连接了相邻两条平行的{Cu(SCN)}n 链,生成二维结构。     

含吡啶环大环多胺的合成及其与Cu(Ⅱ)的络合行为

本文以2,6-二溴甲基吡啶和对甲苯磺酰胺钠盐合成含吡啶环大环多胺,得到了尚未见文献报道的含四个吡啶环的三十二环胺. 2,6-二溴甲基-吡啶与甲苯磺酰胺钠盐在无水乙醇回流温度下得到1,9,17,25-四甲苯磺酰基大环多胺.用浓硫酸脱去N-甲苯磺酰基化合物的甲苯磺酰基, 生成标题大环多胺化合物. 配体与Cu(Ⅱ)的络合由紫外吸收光谱测定. 实验结果表明配体确与Cu^2^+以1:2络合成为双核络合物.     

Cu(I)-Ce(IV)-Y吸附剂的制备及其脱硫性能研究

采用液相离子交换Cu、Ce离子制备了Cu(I)-Y、Ce(IV)-Y和Cu(I)-Ce(IV)-Y吸附剂,利用XRD、BET等技术对吸附剂进行了表征。通过静态实验考察了制备条件对Cu(I)-Ce(IV)-Y吸附剂脱硫性能的影响,通过固定床实验研究了吸附剂的穿透硫容,同时,在含噻吩与苯并噻吩的正辛烷模拟油中,分别加入甲苯、环己烯、吡啶配成新的模拟油,探究了吸附剂的脱硫选择性。结果表明,离子交换时间48 h,焙烧温度550℃,Cu/Ce物质的量比1∶1下制备的Cu(I)-Ce(IV)-Y吸附剂具有适宜的脱硫活性。在含甲苯、环己烯模拟油中,Cu(I)-Ce(IV)-Y吸附剂具有最好的脱硫性能,相同浓度的甲苯、环己烯和吡啶对各吸附剂脱硫性能的影响顺序为吡啶环己烯甲苯。引入Cu+可改善吸附剂的脱硫活性,引入Ce4+可改善吸附剂对硫化物的选择性,Cu+和Ce4+的协同作用使Cu(I)-Ce(IV)-Y兼具有高的硫容和抗芳烃、烯烃能力。     

Cu(I)配位聚合物 [Cu3(CN)3(3-pytpy)]n的合成、晶体结构及其荧光性质

在160 °C下, 以4"-(4-吡啶基)-3,2":6",3"-三联吡啶 (3-pytpy) 为配体,Cu(OAc)2.H2O为金属盐, 通过水热法在乙腈/水的混合溶剂中合成了一个Cu(I) 配位聚合物 [Cu3(CN)3(3-pytpy)]n (1)。通过元素分析、红外光谱 (IR)、X-射线粉末衍射 (XRD) 和热重分析 (TGA) 对配合物1进行了表征,并用X-射线单晶衍射分析确定了晶体结构。结果表明, 其晶体属单斜晶系, 空间群为P21/c, Mr = 579.03, a = 7.132 (6) ?, b = 17.431 (13) ?, c = 18.388 (13) ?, β = 94.284 (14)°, V =2280 (3) ?3, F(000) =1152, Z = 4, ?(MoKα) = 2.799 mm-1, Dc = 1.687 g/cm3, 最终残差因子R1 = 0.0447 , wR2 = 0.1238。Cu(I) 均为畸变三角形配位模式, 配位原子分别为：三联吡啶配体吡啶环上的N原子、CN-基N原子和另一个CN-基C原子。CN-基桥联Cu(I) 离子形成沿ac平面对角线方向延伸的一维内消旋螺旋链 [Cu(I)-CN]n, 配体3-pytpy则进一步桥联这些一维链形成二维 “波浪型” 网络结构, 2D层以ABAB方式堆积并通过吡啶环间的π...π堆积作用拓展为三维超分子结构。     

一种新的活性自由基聚合:单电子转移-活性自由基聚合

介绍了一种新的活性自由基聚合-单电子转移活性自由基聚合(SET-LRP)。SET-LRP的机理是基于Cu(I)在某些溶剂中的歧化反应和Cu(0)通过外层电子转移(OSET)使引发剂R-X生成自由基离子[R-X].-,自由基离子通过异裂生成自由基R.,从而引发单体进行聚合。讨论了引发剂、催化剂、溶剂和配体对SET-LRP的影响。通过与原子转移自由基聚合(ATRP)的对比,表明用于ATRP的引发剂也能广泛应用于SET-LRP,而用于SET-LRP的配体必须是能使络合物高度不稳定、能够使Cu(I)迅速发生歧化反应的配体;通过比较还显示出SET-LRP巨大的优越性:单体适应范围广、反应速率快、反应条件简单、催化剂容易脱除、反应产物没有颜色变化。总之,SET-LRP将有其广阔的应用前景。     

一种在ATRP反应体系中常用引发组分--1-溴乙基苯的荧光光谱研究

采用荧光光谱和吸收光谱方法对ATRP聚合体系的常用引发组分——— 1 溴乙基苯与几种常用配体间的相互作用问题进行了研究 .发现当以联吡啶为络合物配体时 ,无论荧光和吸收光谱中均出现反常的新峰 ,这和 1 溴乙基苯与吡啶间发生了成盐反应有关 .在以长链脂肪胺为络合物配体时 ,特别当金属离子与配体的摩尔比为 1 4时 ,荧光光谱中可清晰的观察到激基复合物发光 .所观察到的这些现象 ,特别是 1 溴乙基苯与联吡啶间的成盐反应 ,对ATRP过程会产生不良影响 .而脂肪胺体系生成的激基复合物由于发生于激发态 ,因此它就不像联吡啶的成盐反应哪样 ,会严重影响反应进行 ,导致ATRP效率的降低 .     

部分季胺盐化聚4-乙烯基吡啶-Cu(II)络合物链的构象和静电效应对催化活性的影响

用溴乙烷部分季胺盐化的聚4-乙烯基吡啶(EBQP4VP)-Cu(Ⅱ)络合物具有类氧化酶特性,它在25℃下催化氢醌的氧化反应是典型的 Michaelis-Menten型动力学行为,络合物分子链的构象和静电效应随“静态”-微化学环境和“动态”-溶液条件变化而异。因而,高分子-Cu(Ⅱ)络合物溶液的催化活性和比浓粘度随着高分子配体季胺盐化度(Q)、溶液PH值、离子强度、温度、乙醇组成和Cu(Ⅱ)离子浓度的不同而变化。     

丝胶蛋白质与铜(Ⅱ)的配位反应

本文运用pH滴定、光谱法、电子自旋波谱、X射线衍射研究丝胶蛋白质与铜 (Ⅱ )的配位反应及其络合物的高次结构 .当溶液的 pH >9 1时 ,丝胶蛋白质与Cu(Ⅱ )生成了稳定的络合物 ,此络合物具有拉伸八面体Cu(N) 4(OH-) 2 型配位结构 ,高次结构为无规卷曲非晶结构 .     

碳酸根桥联的三核铜(Ⅱ)和锌(Ⅱ)配合物

合成出化学式为 [(CuTPA) 3 ( μ3 CO3 ) ](ClO4) 4和 [(ZnTPA) 3 ( μ3 CO3 ) ](ClO4) 4(TPA为三 ( 2 甲基吡啶 )胺 )的配合物 .晶体结构分析表明 ,CO2 -3 作为三齿桥联配体分别把 3个Cu(TPA)单元和Zn(TPA)单元组装成一个新的三核Cu(Ⅱ )和三核Zn(Ⅱ )配合物 .CO2 -3 来自大气中的CO2 .Cu(Ⅱ )离子和Zn(Ⅱ )离子均为五配位三角双锥的配位构型 .变温磁化率测定表明 ,Cu(Ⅱ )离子之间存在着很弱的反铁磁相互作用 .     

Utilization of poly(vinylchloride) and poly(vinylidenefluoride) as macroinitiators for ATRP polymerization of hydroxyethyl methacrylate: Electroanalytical and graft‐copolymerization studies

The utilization of poly(vinylchloride) (PVC) and poly(vinylidenefluoride) (PVDF) as macroinitiators for atom transfer radical polymerization (ATRP) of hydroxyethyl methacrylate (HEMA) was studied performing electroanalytical investigations and “grafting from” experiments to evaluate the potential modification of such commercial polymers by ATRP. The study was performed changing various operating parameters such as the nature of the copper salt, the ligand, the solvent, the temperature, and the reaction time. Electroanalytical data suggest that PVC can be easily activated by both CuCl/Tris(2‐pyridylmethyl)amine (TPMA) and CuCl/Tris[2‐(dimethylamino)ethyl]amine (Me₆TREN), two catalytic systems widely adopted for ATRP reactions, in a wide range of operating conditions. PVDF is more difficult to be activated, due to the higher strength of the C? F bond. In particular, the utilization of high temperature and of a more reductant redox couple such as Cu(I)Me₆TREN/Cu(II)Me₆TREN was needed to achieve a significant degree of grafting. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2524–2536     

Tetramethylguanidino‐tris(2‐aminoethyl)amine: A novel ligand for copper‐based atom transfer radical polymerization

With CuBr/tetramethylguanidino‐tris(2‐aminoethyl)amine (TMG₃‐TREN) as the catalyst, the atom transfer radical polymerization (ATRP) of methyl methacrylate, n‐butyl acrylate, styrene, and acrylonitrile was conducted. The catalyst concentration of 0.5 equiv with respect to the initiator was enough to prepare well‐defined poly(methyl methacrylate) in bulk from methyl methacrylate monomer. For ATRP of n‐butyl acrylate, the catalyst behaved in a manner similar to that reported for CuBr/tris[2‐(dimethylamino)ethyl]amine. A minimum of 0.05 equiv of the catalyst with respect to the initiator was required to synthesize the homopolymer of the desired molecular weight and low polydispersity at the ambient temperature. In the case of styrene, ATRP with this catalyst occurred only when a 1:1 catalyst/initiator ratio was used in the presence of Cu(0) in ethylene carbonate. The polymerization of acrylonitrile with CuBr/TMG₃‐TREN was conducted successfully with a catalyst concentration of 50% with respect to the initiator in ethylene carbonate. End‐group analysis for the determination of the high degree of functionality of the homopolymers synthesized by the new catalyst was determined by NMR spectroscopy. The isotactic parameter calculated for each system indicated that the homopolymers were predominantly syndiotactic, signifying that the tacticity remained the same, as already reported for ATRP. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5906–5922, 2005     

N,N-二乙基硫代氨基甲酰硫基团(S_2CNEt_2)为假卤原子转移的原子转移自由基聚合新体系

综述了原子转移自由基聚合 (ATRP)中 ,以N ,N 二乙基硫代氨基甲酰硫基团 (S2 CNEt2 )转移实现活性聚合、控制聚合物结构的 4种新方法 :非卤化物 ,N ,N 二乙基二硫代氨基甲酸亚铜 [Cu(S2 CNEt2 ) ]催化甲基丙烯酸甲酯 (MMA)的正向ATRP ;2 ,2′ 联吡啶存在的条件下 ,过氧化苯甲酰 (BPO)与Cu(S2 CNEt2 )的氧化还原反应控制MMA的本体反向ATRP;同时含可转移卤原子、基团的氯化二乙基二硫代氨基甲酸铜 [Cu(S2 CNEt2 ) Cl]成功地用于偶氮二异丁腈或BPO引发的乙烯类单体反向ATRP.假卤原子S2 CNEt2 转移的ATRP得到窄分布的精确结构聚合物分子链ω 端含有光敏基团S2 CNEt2 ,可引发乙烯类单体的常温光聚合 ,实现ATRP与光聚合相结合制备嵌段共聚物     

Effect of ligand on the synthesis of star polymers by resorcinarene‐based ATRP initiators

The effect of the steric hindrance on the initiating properties of two multifunctional resorcinarene‐based initiators in atom transfer radical polymerization (ATRP) was studied by using Cu(I)‐complexes of three multidentate amine ligands in the polymerization of tert‐butyl acrylate and methyl methacrylate. These ligands are less sterically hindered and have higher activities in the catalysis of ATRP of (meth)acrylates than 2,2′‐bipyridine. The polymerizations were faster and more controlled than with the 2,2′‐bipyridyl catalyst, but the tendency for bimolecular coupling increased. Even though the initiator was octafunctional, the resulting star polymers had only four arms. This indicates that the steric hindrance arising from the conformations of the initiators determines the structure of the polymer, but the ligand noticeably affects the controllability of the polymerization © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3349–3358, 2005     

Effect of variation of [PMDETA]0/[Cu(I)Br]0 ratio on atom transfer radical polymerization of n‐butyl acrylate

A kinetic study was conducted to examine the effect of varying the ratio of ligand to transition metal in a Cu(I)Br/N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) catalyst system for atom transfer radical polymerization (ATRP) of n‐butyl acrylate (nBA) using methyl 2‐bromopropionate as the initiator. Experimental molecular weights were higher than theoretical when low molecular weight polymers were targeted at low ratios of [PMDETA]₀/[Cu(I)Br]₀ (< 1), indicating inefficient initiation/deactivation. A downward curvature in the plot of M_n versus conversion was observed at high monomer conversion when targeting high molecular weight polymers. This deviation became more significant when an excess of ligand was used, indicating a contribution of chain transfer to ligand. The maximum rate of polymerization was obtained at [PMDETA]₀/[Cu(I)Br]₀ ≈ 0.5 for bulk ATRP of nBA; however for polymerization in the presence of 10 vol% DMF, the maximum appeared at the ratio ≈ 1:1. Addition of acetone or DMF improved solubility of Cu(II) complex, which consequently improved the level of control over the polymerization at low ratios of [PMDETA]₀/[Cu(I)Br]₀, but also reduced the reaction rate. The polymerization rate increased with temperature, but at the expense of increased polydispersities. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3285–3292, 2004     

Copper(I) and -(II) complexes of neutral and deprotonated N-(2,6-diisopropylphenyl)-3-[bis(2-pyridylmethyl)amino]propanamide

As part of a study of atom-transfer radical polymerization (ATRP) catalysts, four new copper(I) and -(II) compounds of a new monoanionic, tripodal tetradentate ligand, N-(2,6-diisopropylphenyl)-3-[bis(2-pyridylmethyl)amino]propanamide (DIPMAP), were prepared. Ligand synthesis followed from the addition-elimination reaction of 2,6-diisopropylaniline with acryloyl chloride and then a Lewis acid catalyzed Michael addition of bis(2-pyridylmethyl)amine to this product. The ligand was complexed to CuCl to yield monomeric Cu(DIPMAP)Cl featuring an intramolecular hydrogen bond between the free amide hydrogen and the coordinated chloride ligand. Deprotonation of the amide hydrogen in Cu(DIPMAP)Cl using n-BuLi led to the incorporation of LiCl in the resulting product, Li2Cu2(DIPMAP)2Cl2. This complex exhibited an unusual dimeric structure, with the amine nitrogens of one ligand coordinated to a lithium ion, the amide oxygen of the same ligand bridging between the lithium ions, and the amidate nitrogen of that ligand coordinated to a CuCl unit that has a structure analogous to dihalocuprate ions. Deprotonation of Cu(DIPMAP)Cl using KOtBu yielded an alkali-metal chloride free product, Cu2(DIPMAP)2, that also exhibited a dimeric structure in which the three amine nitrogens of one ligand were coordinated to one CuI ion and the amidate nitrogen of the same ligand was coordinated to the other CuI ion. Cu2(DIPMAP)2 was effective in abstracting halogen atoms from organic halides, but in the attempted ATRP of tert-butyl acrylate, molecular weight versus conversion behavior reminiscent of a redox-initiated polymerization was observed. DIPMAP was coordinated to CuBr2 to yield [Cu(DIPMAP)Br]Br with a square-pyramidal structure. The amide hydrogen in this complex could be deprotonated using KOtBu to form complex [DIPMAP]CuBr. Spectral characterization of complex confirmed deprotonation of the ligand and that it most likely had an axially distorted trigonal-bipyramidal structure, although crystals suitable for X-ray analysis could not be obtained. Solution oxidation of Cu2(DIPMAP)2 using CBr4 yielded a product, complex, whose spectral signatures did not match those of complex. The dimeric structure of Cu2(DIPMAP)2 might be a significant contributing factor to the slow rate of deactivation observed in atom-transfer reactions using Cu2(DIPMAP)2 as the catalyst.     

Poly(acrylate‐b‐styrene‐b‐isobutylene‐b‐styrene‐b‐acrylate) Block Copolymers via Carbocationic and Atom Transfer Radical Polymerizations

A series of polyacrylate‐polystyrene‐polyisobutylene‐polystyrene‐polyacrylate (X‐PS‐PIB‐PS‐X) pentablock terpolymers (X=poly(methyl acrylate) (PMA), poly(butyl acrylate) (PBA), or poly(methyl methacrylate) (PMMA)) was prepared from poly (styrene‐b‐isobutylene‐b‐styrene) (PS‐PIB‐PS) block copolymers (BCPs) using either a Cu(I)Cl/1,1,4,7,7‐pentamethyldiethylenetriamine (PMDETA) or Cu(I)Cl/tris[2‐(dimethylamino)ethyl]amine (Me₆TREN) catalyst system. The PS‐PIB‐PS BCPs were prepared by quasiliving carbocationic polymerization of isobutylene using a difunctional initiator, followed by the sequential addition of styrene, and were used as macroinitiators for the atom transfer radical polymerization (ATRP) of methyl acrylate (MA), n‐butyl acrylate (BA), or methyl methacrylate (MMA). The ATRP of MA and BA proceeded in a controlled fashion using either a Cu(I)Cl/PMDETA or Cu(I)Cl/Me₆TREN catalyst system, as evidenced by a linear increase in molecular weight with conversion and low PDIs. The polymerization of MMA was less controlled. ¹H‐NMR spectroscopy was used to elucidate pentablock copolymer structure and composition. The thermal stabilities of the pentablock copolymers were slightly less than the PS‐PIB‐PS macroinitiators due to the presence of polyacrylate or polymethacrylate outer block segments. DSC analysis of the pentablock copolymers showed a plurality of glass transition temperatures, indicating a phase separated material.     

Design and Application of Amphiphilic Polymeric Supports for Micellar Catalysis

In this contribution, the synthesis and application of amphiphilic poly(2-oxazoline)s with covalently bound transition metal catalysts for reactions in aqueous media is described. In the first example, bipyridine moieties were introduced via living ring-opening polymerization of functionalized oxazoline monomers and the resulting block copolymers were used as macroligands for ATRP (atom transfer radical polymerization) using Cu(I)Br as active metal species. Furthermore, the fixation of a chiral biphosphane and its use for enantioselective hydrogenation of enamides is presented as well as the fixation of a ruthenium catalyst. The latter one is used for polymerization of diethyl dipropargylmalonate (DEDPM), and represents the first example of an alkyne polymerization using a ruthenium catalyst. In the case of the polymers stable latex particles were obtained     

Triphenylphosphine as reducing agent for copper(II)-catalyzed AGET ATRP

Triphenylphosphine(TPP) was used as reducing agent to continuously generate the Cu(I) activator in copper(II)-catalyzed activators generated by electron transfer atom transfer radical polymerization(AGET ATRP). For example, the polymers prepared with a molar ratio of [MMA]0/[EBi B]0/[Cu Cl2]0/[PMDETA]0/[TPP]0 = 500/1/0.1/0.5/0.5 had controlled molecular weights and low molecular weight distribution(Mw/Mn) values(~1.2). TPP as a commercial reducing agent provides a convenient copper-catalyzed AGET ATRP procedure for the preparation of well-defined polymers.     

NEW INITIATION SYSTEMS FOR ATOM TRANSFER RADICAL POLYMERIZATION

This review summarizes our achievements in designing new initiation systems for atom transfer radical polymerization (ATRP). First-order kinetics and extension experiments revealed the living nature of these reactions. Tailormade vinyl polymers with functional end groups were characterized by ^1H-NMR and UV-vis spectroscopic analyses. Replacing traditional radical initiators AIBN and BPO, carbon-carbon bond compounds, 1,1,2,2-tetraphenyl-l,2-ethanediol, diethyl 2,3-dicyano-2,3-diphenylsuccinate and diethyl 2,3-dicyano-2,3-di(p-tolyl)succinate, were utilized in reverse ATRP to produce the initiating radical. Sulfur-sulfur bond iniferter, tetraethylthiuram disulfide (TD), in conjunction with CuBr/bpy or NiCI2/PPh3 complex could control the styrene polymerization via redox reaction. Pseudo-halogen transfer reaction was demonstrated to maintain the dormant-active species equilibrium in normal and reverse ATRP with Cu(S2CNEt2), Cu(S2CNEt2)CI and Fe(S2CNEt2)3 as catalysts. The organic halide initiator and reduced transition metal compound that started the living polymerization were produced in situ from the components of TD/FeCI3/PPh3, TD/CuBr2/bpy and Fe(S2CNEt2)3/FeCI3/PPh3 systems. Accurate control of UV irradiation time favored the radical generation process in photo ATRP with the 2,2-dimethoxy-2-phenylacetophenone/Fe(S2CNEt2)3 initiation system.