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1.
合成了3种金属配合物{[Cd(pztc)(H2O)2]·(H2bpy)·3(H2O)}n(1),{[Zn3(pztc)2(Hbpy)2(bpy)(H2O)4]·7H2O}n(2),[Cu6(pztc)4(Hbpy)4(bpy)2(H2O)8]·17H2O(3)(bpy=4,4′-联吡啶,H4pztc=吡嗪-2,3,5,6-四甲酸),并对其进行了红外光谱分析、元素分析、热重分析、荧光光谱分析和X-射线单晶衍射分析。其中1和3中存在丰富的氢键,2为3D网状结构,存在金鱼状(H2O)10水簇。3为由化学键连接成的1D链状结构,由氢键连接成3D超分子结构。当激发光波长为320 nm时,1和2的最大荧光发射峰分别在496 nm和494 nm。  相似文献   

2.
合成了3种金属配合物{[Cd(pztc)(H2O)2]·(H2bpy)·3(H2O)}n(1),{[Zn3(pztc)2(Hbpy)2(bpy)(H2O)4]·7H2O}n(2),[Cu6(pztc)4(Hbpy)4(bpy)2(H2O)8]·17H2O(3)(bpy=4,4′-联吡啶,H4pztc=吡嗪-2,3,5,6-四甲酸),并对其进行了红外光谱分析、元素分析、热重分析、荧光光谱分析和X-射线单晶衍射分析。其中1和3中存在丰富的氢键,2为3D网状结构,存在金鱼状(H2O)10水簇。3为由化学键连接成的1D链状结构,由氢键连接成3D超分子结构。当激发光波长为320 nm时,1和2的最大荧光发射峰分别在496 nm和494 nm。  相似文献   

3.
水热法合成得到2个配合物, {[Zn7(L)4(bpe)2(μ3-OH)2(H2O)8]·4H2O}n(1), 和{[Cd3(L)2(bpy)2.5(H2O)]·5.5H2O}n(2)(H3L=3-(carboxymethoxy)benzene-1,2-dioic acid, bpe=1,2-bis(4-pyridyl)-ethene, bpy=4,4'-bipyridine), 并采用元素分析、红外光谱、热重和X-射线单晶衍射对其结构进行表征。配合物1中, 配体L3-和bpe连接[Zn5( μ3-OH)2]中心形成一维链, 这样的链通过氢键连接成三维的超分子结构。配合物2呈现(3,3,6)连接的网状结构。此外, 对配合物12的荧光性质进行了研究。  相似文献   

4.
在水热条件下,以N-氧化-2-吡啶膦酸(H2L)为主配体,4,4′-联吡啶(bpy)为桥联配体,合成了3个铜有机膦酸配合物:{[Cu(L)(bpy)0.5(H_2O)]·2H_2O}n(1),{[Cu(HL)2(bpy)]·4H_2O}n(2)和{[Cu2(L)2(bpy)]·3H_2O}n(3)。配合物1中,相邻的铜离子由2个膦酸根连成二聚体,二聚体之间通过bpy桥联成一维链。配合物2中,单核[Cu(HL)2]被bpy连接成一维链。配合物3中,四聚体[Cu2(L)2]2被bpy连接成"砖块状"结构的二维层。磁性研究表明,配合物1和3中铜离子之间存在反铁磁性耦合。  相似文献   

5.
采用水热合成的方法,在以5-(4-羟基吡啶基甲基)间苯二甲酸(H2L)作主配体、4,4′-联吡啶(4,4′-bpy)和1,2-二(4-吡啶基)乙烯(bpe)作辅配体的条件下,得到2种新颖的Zn(Ⅱ)配位聚合物{[Zn(L)(4,4′-bpy)0.5]·2H2O}n(1)和{[Zn(L)(bpe)0.5]·2H2O}n(2)。配合物通过单晶X射线衍射的方法进行了结构分析,并进一步通过红外光谱(IR)、元素分析、PXRD和热重分析(TG)的方法进行了表征。结构分析表明配合物1展现出的是一种三维三重互穿网络;聚合物2为二维双层结构,并进一步组合成了三重平行互穿的2D→3D的空间网络。此外,研究了配合物的荧光性质。  相似文献   

6.
合成了3个配合物{[Zn_3(L)_2(SO_4)_2(H_2O)_4]·H_2O}n(1)、{[Cd_2(L)_2(SO_4)(H_2O)]·H_2O}n(2)和{[Cd(L)I]·CH_3OH}n(3)(HL=N′-nicotinoylpyrazine-2-carbohydrazonamide),并通过单晶X射线衍射、红外、元素分析和粉末X射线衍射等手段进行表征。配合物1中,采用μ3-η1η1η1配位模式的SO_4~(2-)把Zn(Ⅱ)连接成无机网状二维平面(bc面),有机配体HL交错的分布在网状平面的两侧,这些二维层在分子间氢键的作用下形成三维超分子结构。配合物2是由配体HL连接[(Cd2)2(μ2-SO4)2]和Cd1两种节点形成的二维结构,相邻的二维层在π…π堆积作用下形成三维超分子结构。配合物3是一维的Z字链结构,这些一维链在氢键的连接作用下形成二维的超分子网络结构。光催化降解亚甲基蓝实验结果表明,在双氧水存在时配合物1~3均表现出很好的降解效果。  相似文献   

7.
分别以E-3-[4-(羧甲氧基)-苯基]丙烯酸(H2L1)和E-3-[3-(羧甲氧基)-苯基]丙烯酸(H2L2)为主配体,合成了3种钴(Ⅱ)配位聚合物:[Co(L1)(bpp)]n(1),{[Co(μ3-OH)2(L2)4(bpy)2(H2O)4]·12H2O}n(2)和[Co(L2)(bpy)]n(3)(bpp:1,3-二吡啶基丙烷,bpy:4,4-联吡啶)。通过元素分析、红外光谱、X射线粉末和单晶衍射对其进行了结构表征。结果表明钴(Ⅱ)离子在这3种配合物中具有不同的配位环境,导致3种配合物具有不同的晶体结构和磁性特征。  相似文献   

8.
合成了2个锌配合物[Zn(mtyaa)2(H_2O)4]·4H_2O(1)和[Zn(bpe)(mtyaa)2(H_2O)2]n(2)(Hmtyaa=2-(5-甲基-1,3,4-噻二唑)-硫乙酸;bpe=1,2-双(4-吡啶基)乙烷),用X射线单晶衍射仪测定了配合物的单晶结构,并对它进行了元素分析、红外光谱、热重和粉末X射线衍射等表征。配合物1和2的晶体分别属于三斜晶系和单斜晶系,空间群分别为P1和C2/c。π-π相互作用以及配位水和游离水分子与羧基氧之间的氢键作用将配合物1的单分子结构连成三维网状结构。配合物2中配位水与羧基氧以及配体中的氮原子之间的氢键作用将相邻链连接成二维平面结构。  相似文献   

9.
通过水热合成得到3个有机金属配位聚合物,即[Cu(1,2-BDC)(L)](1),[Cu(HBTC)(L)]·2H2O(2),[Co(HBTC)(L)]·H2O(3),(L=N,N-双(3-氨基吡啶)乙二酰胺,1,2-H2BDC=1,2-邻苯二甲酸和H3BTC=1,3,5-均苯三甲酸)。配合物1是基于1D[Cu-1,2-BDC]n和[CuL]n链形成的一个3DCdSO4-型拓扑结构。配合物2~3是同构的,均显示出2D双层(3,5)-连接的{42·67·8}{42·6}拓扑结构。相邻的2D双层网络通过分子间的氢键(配合物2)和π-π堆积(配合物3)作用进一步拓展成3D超分子框架。我们对芳香羧酸和中心金属离子对配合物结构的影响进行了详细的讨论。此外,还研究了配合物1~3的电化学性质和固态荧光性质。  相似文献   

10.
用水热法合成了3个配位聚合物并测定了其晶体结构,分子式分别为[Zn_2(tba)_2(bpy)]_n(1),[Zn_2(tba)_2(bpe)]_n(2)和[Zn(tba)(bpp)]_n(3),(tba=2,2′-thiobis(benzoic acid),bpy=4,4′-bipyridine,bpe=1,2-bis(4-pyridyl)ethylene,bpp=1,3-bis(4-pyridyl)propane)。tba是由2-(2-cyanophenylthio)benzoic acid原位水解得到的。X射线单晶衍射分析表明配合物1含双核锌单元,由tba和bpy连成二维(4,4)网。配合物2是基于[Zn_2(tba)_2]_n子链,由bpe连接而成的钻石拓扑三维结构。有趣的是,配合物3是一个由(4,4)网交缠形成的二维到二维的聚索烃。Tba配体构型和各双吡啶辅助配体引起了3个化合物的结构各异性。此外,研究了3个配位聚合物的荧光性质。  相似文献   

11.
The preparation, properties, and reactions of the compounds named in the title are described, with particular reference to the possible participation of (p→d)π components in the bonding between the group IVB and the group VB elements.  相似文献   

12.
The design of a relatively simple and efficient method to extend the π‐conjugation of readily available aromatics in one‐dimension is of significant value. In this paper, pyrenes, peropyrenes, and teropyrenes were synthesized through a double or quadruple benzannulation reaction of alkynes promoted by Brønsted acid. This novel method does not involve cyclodehydrogenation (oxidative aryl–aryl coupling) to arrive at the newly incorporated large arene moieties. All of the target compounds were synthesized in moderate to good yields and were fully characterized with the structures unambiguously confirmed by X‐ray crystallography. As expected, photophysical characterization clearly shows increasing red‐shifts as a function of extended conjugation within the fused ring systems.  相似文献   

13.
The design of a relatively simple and efficient method to extend the π‐conjugation of readily available aromatics in one‐dimension is of significant value. In this paper, pyrenes, peropyrenes, and teropyrenes were synthesized through a double or quadruple benzannulation reaction of alkynes promoted by Brønsted acid. This novel method does not involve cyclodehydrogenation (oxidative aryl–aryl coupling) to arrive at the newly incorporated large arene moieties. All of the target compounds were synthesized in moderate to good yields and were fully characterized with the structures unambiguously confirmed by X‐ray crystallography. As expected, photophysical characterization clearly shows increasing red‐shifts as a function of extended conjugation within the fused ring systems.  相似文献   

14.
The rare earth-silver-stannides YAgSn, TmAgSn, and LuAgSn were synthesized from the elements by arc-melting and subsequent annealing. The three stannides were investigated by X-ray powder and single-crystal diffraction: NdPtSb type, P63mc, Z=2, a=468.3(1), pm, wR2=0.0343, 353 F2 values, 12 variables for YAgSn, and ZrNiAl type, P6¯2 m, a=726.4(2), , wR2=0.0399, 659 F2 values, 15 variables for TmAgSn, and a=723.8(2), , wR2=0.0674, 364 F2 values, 15 variables for LuAgSn. Besides conventional laboratory X-ray data with monochromatized Mo radiation, the structures were also refined on the basis of synchrotron data with , in order to clarify the silver-tin ordering more precisely. YAgSn has puckered, two-dimensional [AgSn] networks with Ag-Sn distances of 278 pm, while the [AgSn] networks of TmAgSn and LuAgSn are three-dimensional with Ag-Sn distances of 279 and 284 pm for LuAgSn. Susceptibility measurements indicate Pauli paramagnetism for YAgSn and LuAgSn. TmAgSn is a Curie-Weiss paramagnet with an experimental magnetic moment of 7.2 μB/Tm. No magnetic ordering is evident down to 2 K. The local environments of the tin sites in these compounds were characterized by 119Sn Mössbauer spectroscopy and solid-state NMR (in YAgSn and LuAgSn), confirming the tin site multiplicities proposed from the structure solutions and the absence of Sn/Ag site disordering. Mössbauer quadrupolar splittings were found in good agreement with calculated electric field gradients predicted quantum chemically by the WIEN2k code. Furthermore, an excellent correlation was found between experimental 119Sn nuclear magnetic shielding anisotropies (determined via MAS-NMR) and calculated electric field gradients. Electronic structure calculations predict metallic properties with strong Ag-Sn bonds and also significant Ag-Ag bonding in LuAgSn.  相似文献   

15.
Boron cations are elusive and highly electrophilic species that play a key role in the chemistry of boron. Despite early interest in the chemistry of boron cations, until recently they have largely remained chemical curiosities. However, hints at harnessing their potential as potent electrophiles have begun to appear and developments in weakly coordinating anion technology suggest that this is an area of research that is ripe for exploration. It has been nearly 20 years since the last major review on boron cations; herein we summarize the progress in the area since that time.  相似文献   

16.
17.
A systematic quantum chemical investigation of mono-, di-, and triaminoborane, -alane, -gallane, and -indane is carried out to determine quantitatively the effects of pi bonding and negative hyperconjugation on structures, energetics, and rotational barriers in these systems. Pi bonding plays a significant role in the aminoborane compounds, but becomes rapidly less significant in the aminoalanes, -gallanes, and -indanes. For each main-group metal X investigated, X-N rotational barriers are found to be essentially equal depending only on the number of remaining in-plane amino groups. The contribution of negative hyperconjugation to reducing rotational barriers, as assessed from natural bond orbital (NBO) delocalization energies, is independent of the pyramidalization of the out-of-plane amino group, and is also dependent only on the number of rotated groups. Optimized tris[bis(trimethylsilyl)amino]-substituted structures of boron, aluminum, gallium, and indium are found to compare quite well with available experimental structural data, and exhibit X-N torsion angles that are independent of the central metal atom.  相似文献   

18.
铬,硒,镉,锰与心脑血管疾病   总被引:1,自引:0,他引:1  
通过对50例心脑血管疾病病人及50例健康对照组血中微量元素铬、硒、镉、锰的检测分析证实,心脑血管疾病病人血清Cr、Se含量下降,Cd含量未见明显升高,并进一步探讨了这些微量元素与心脑血管疾病的发生发展的关系及其临床意义。  相似文献   

19.
Various low-dimensional nanostructures, such as nanowires, nanotubes, nanosheets, and fullerene-like nanoparticles have been selectively synthesized from rare-earth compounds (hydroxides, fluorides) based on a facile hydrothermal method. The subsequent dehydration, sulfidation, and fluoridation processes lead to the formation of rare-earth oxide, oxysulfide, and oxyhalide nanostructures, which can be functionalized further by doping with other rare-earth ions or by coating with metal nanoparticles. Owing to the interesting combination of novel nanostructures and functional compounds, these nanostructures can be expected to bring new opportunities in the vast research areas of and application in biology, catalysts, and optoelectronic devices.  相似文献   

20.
A new protocol for the Ullmann-type arylation process of different aromatic heterocycles without any transition-metal catalyst, implying the use of a combination of an excess of potassium hydroxide and dimethyl sulfoxide, is described. The reaction can be performed between a broad range of starting nucleophiles including phenol, alcohols, amines, nitrogen-containing five-membered systems such as pyrazoles, imidazoles, and indoles, and amides with haloarenes, iodide and bromide derivatives giving the best results, the possible pathway involving the in situ generation of the corresponding benzyne intermediate. When the reaction was performed with 2-iodoaniline and either carboxamides or isothiocyanato derivatives, the corresponding benzoazole derivatives were obtained.  相似文献   

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