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1.
采用密度泛函理论研究气相和四氢呋喃(THF)溶剂中Cp 4An和COT 2An(Cp -=C 5H 5-,COT 2-=C 8H 2-,An=U(Ⅳ),Pu(Ⅳ))配合物的性质。THF溶剂对配合物的溶剂化效应采用类导体极化连续模型(CPCM)近似计算。计算结果显示在THF溶液中各配合物结合能的大小顺序为COT2Pu > COT2U > Cp4Pu > Cp4U。溶剂化效应降低了该金属有机配合物的结合能。计算得到的化合物的结构参数和红外光谱数据与实验数据保持一致。通过对Cp4An和COT2An(An=U(Ⅳ),Pu(Ⅳ))的分子轨道能级图分析发现,采用最高的RSC-ECP赝势计算COT2U和Cp4U的基态分别为三重fφ2和fσ2组态;而COT2Pu和Cp4Pu的基态分别为五重fσ1fπ1fφ2和fσ3fδ1组态。 相似文献
2.
基于3-(2,4-二羧基苯基)-6-羧基吡啶配体(H 3dpcp),利用溶剂热法制备了发光配合物[Zn(H 2dpcp) 2(H 2O) 2]·H 2O( 1)。配合物 1具有新颖的单核蝴蝶状结构,通过 π… π相互作用延伸成三维超分子结构。实验结果表明,配合物 1在pH=1~10的水溶液中表现出优异的发光稳定性。值得注意的是,配合物 1不仅可以利用荧光增强效应高选择性和可循环性地检测PO 43-离子,并且Fe 3+离子可以使配合物 1的发光显著猝灭。对硝基芳香族爆炸物的荧光传感实验表明,配合物 1可以作为发光探针高选择性、灵敏性地检测2,4,6-三硝基苯酚(TNP),同时具有较低的检测限。此外,还详细探究了配合物 1对上述分析物的发光传感机理。 相似文献
3.
用水热法合成了NaYW 2O 8∶Ln 3+(Ln=Yb/Er and Eu)微米晶,并研究了pH值对微米晶组成、形貌和荧光性质的影响。通过调节微米晶的形貌和结构对微米晶的上转换荧光进行了调控。在NaYW 2O 8∶Eu 3+微米晶的激发光谱中,Eu 3+-O 2电荷迁移带和W 6+-O 2- 跃迁与Eu 3+离子的 f- f激发峰的比值随着微米晶的形貌和结构的不同发生改变。 相似文献
4.
在相同的反应条件下,基于配体(Hpypymba=4-((3-(吡嗪-2-基)-1 H-吡唑-1-基)甲基)苯甲酸)和过渡金属离子(Co(Ⅱ)、Cd(Ⅱ))合成同构金属掺杂材料[Co xCd 1-x(pypymba) 2] n(0 ≤ x ≤ 1)(配合物 1~5),运用粉末X射线衍射(PXRD)、紫外等分析手段对其结构与形貌进行表征。将得到的MOFs作为催化剂载体负载Ag离子进行4-硝基苯酚的还原反应。研究表明含Co 2+的化合物1是良好的催化剂载体,随着配合物中Cd 2+比例的增加,反应速率下降,甚至对反应有一定的抑制效果。该MOFs对于Ag的最大负载量为47%( w/ w),Ag@compound 1经4次循环后依然有96%的催化效率。 相似文献
5.
合成了3个香豆素Schiff碱单核Zn 2+、Co 2+和双核Ni 2+的配合物,[Zn(L 1) 2]( 1)(HL 1=6-((4-二乙胺基-2-羟基-亚苄基)-氨基)-苯并吡喃-2-酮),[Co(L 2) 2]( 2)(HL 2=6-((4-甲氧基-2-羟基-亚苄基)-氨基)-苯并吡喃-2-酮),[Ni 2(L 3) 2(CH 3OH) 4)]( 3)(H 2L 3=4-羟基-3-((4-甲氧基-2-羟基-亚苄基)-氨基)-苯并吡喃-2-酮)。利用元素分析、红外光谱、紫外可见光谱、荧光光谱及X射线单晶衍射分析等手段对其进行了表征。X射线单晶衍射分析结果表明:配合物 1和配合物 2均为单核结构,由1个金属离子和2个配体单元组成;配合物 3具有双核结构,由2个金属离子、2个配体单元及4个配位的甲醇分子组成。配合物 1、 2和 3分别是单斜晶系、三斜晶系和三斜晶系,所属的空间群分别为 C2/ c、 P1和 P2 1/ n;中心金属Zn 2+和Co 2+离子的空间构型为四配位的四面体,Ni 2+离子的空间构型为六配位的扭曲的八面体。此外,通过对配体HL 1和HL 2的紫外可见光谱性质研究发现,在DMF/H 2O(4:1, V/V)溶液中,自由配体HL 1和HL 2分别可以选择性识别Hg 2+和Zn 2+,通过计算得到其检测限分别为7.45和6.10 μmol·L -1。荧光性质研究发现在DMF/H 2O(4:1, V/V)溶液中自由配体HL 2可以检测Zn 2+,检测限为2.91 μmol·L -1。 相似文献
6.
采用5-((4-吡啶基)甲氧基)-异烟酸(H 2PLIA)、1,3,5-三(1-咪唑基)-苯(TIB)合成了金属有机骨架[Cd (PLIA)(TIB)] n (MOF-1)。MOF-1是具有理想一维孔道的二维结构化合物,其一维孔道由柔性三角形PLIA 2-配体和刚性三角形TIB配体间隔形成。利用MOF-1易掺杂的优势,采用后修饰合成策略制备了Tb@MOF-1。对MOF-1和Tb@MOF-1进行了基本表征及荧光探针性能研究。2种探针材料具有相同的结构。MOF-1和Tb@MOF-1分别对水溶液中的Cr 2O 72-和S 2O 82-离子具有较强荧光识别能力,均有响应时间快,稳定性、选择性、灵敏度高的特点。研究了MOF-1和Tb@MOF-1对Cr 2O 72-和S 2O 82-的荧光识别机理,其不同可能与Tb 3+离子掺杂有关。 相似文献
7.
采用芳香族 π共轭及含氮原子有机连接剂,合成同构铽、铕发光配位聚合物(CPs){[Eu (PLIA) 1.5(H 2O) 2]·H 2O} n ( 1)和{[Tb (PLIA) 1.5(H 2O) 2]·H 2O} n ( 2),其中H 2PLIA=5-((吡啶-4-基甲基)氧基)苯-1,3-二甲酸。对合成的配合物进行了结构测定、表征和荧光痕量识别实验研究。2个同构配合物具有理想的三维框架结构, π… π堆积及氢键等弱相互作用增强了其化学稳定性;表征显示配位聚合物 1和 2具有良好的荧光性质、结晶性、热力学稳定性及结构完整性,可作为荧光传感的材料。 1和 2对水溶液中的Zr 4+、Cr 2O 72-和Fe 3+、HPO 42-具有选择性好、灵敏度高的荧光识别能力,其检出限分别为0.139 μmol·L -1( 1,Zr 4+)、0.626 μmol·L -1( 1,Cr 2O 72-)、0.430 μmol·L -1( 2,Fe 3+)、1.36 μmol·L -1( 2,HPO 42-)。探究了 1和 2作为探针的荧光猝灭机理。更有趣的是, 1和 2具有指纹识别性能,其荧光指纹纹路清晰连贯,细节明显,可被清晰观察。 相似文献
8.
采用高温固相法制备了2个系列的荧光粉样品:Ba 2-xZnGe 2O 7: xBi 3+(系列Ⅰ)和Ba 1.994-yK yZnGe 2O 7:0.006Bi 3+(系列Ⅱ)。X射线衍射(XRD)测试结果表明,少量Bi 3+、K +的掺杂不会明显改变材料的物相结构。样品的荧光光谱测试结果表明,虽然2个系列样品的发光光谱都随组成成分变化有少量变化,但发光颜色基本上均为黄绿色。在358 nm的激发下,荧光粉的发射光谱呈现一个峰值在500 nm的宽发射带,归属于 3P1→ 1S0能级跃迁。在500 nm监测下,荧光粉的最强激发峰位于358 nm,归属于 1S0→ 3P1能级跃迁,此外还有一个位于320 nm的肩峰归属于O 2--Bi 3+电荷转移带。系列Ⅰ样品的光谱数据结果指出,Bi 3+的最佳掺杂量 x为0.006。在该基质中,Bi 3+掺杂取代Ba 2+属于不等价取代,会在晶格中产生Ba 2+空位或间隙O 2-,对材料的发光强度产生负面影响。对此,采用K +与Bi 3+协同掺杂起到电荷补偿的作用,填补Ba 2+空位或捕获间隙O 2-缺陷。空位被填补或间隙被捕获均减少了晶格畸变,从而使发光强度明显提高。系列Ⅱ样品的光谱数据表明,完全电荷补偿的荧光粉样品相比于没有掺K +的样品,其发光强度提高了约2.5倍。 相似文献
9.
通过氯化锰和2-二甲氨基异丙基氯盐酸盐在溶液中的反应,制备了一类绿光分子基晶态材料:(C 5H 13ClN) 2[MnCl 4]( 1)。该材料在紫外光激发后发出强烈的绿色荧光,并且热分析测试表明其具有较好的热稳定性(分解温度大于450 K)。结构和光谱分析表明其优异的光学性能归因于[MnX 4] 2-四面体中Mn 2+的 4T1(G)→ 6A1电子跃迁。 相似文献
10.
Syntheses and structure determination of the Y III complexes with ethylenediaminetetraacetic acid (H 4edta) and trans-1,2-cyclohexanediaminetetraacetic acid (H 4cydta) are reported. The crystal and molecular structures of the complexes, as well as their molecular formulas and compositions,
were determined by single-crystal X-ray structure analyses, NMR, IR, thermogravimetric measurements, and elementary analyses.
The crystal of the Na[Y III(edta)(H 2O) 3]·5H 2O complex belongs to the orthorhombic crystal system and space group Fdd2. The crystal data are as follows: a = 19.355(5) Å, b = 35.431(11) Å, c = 12.122(3) Å, V = 8313(4) Å 3, Z = 16, M = 544.23, D c = 1.739 g·cm −3, μ = 2.908 mm −1 and F(000) = 4480. The final R and Rw are 0.0483 and 0.1172 for 3284 ( I > 2σ( I)) unique reflections, R and Rw are 0.0678 and 0.1440 for all 8499 reflections, respectively. The Y IIIN 2O 7 part in the [Y III(edta)(H 2O) 3] − complex anion has a pseudo-monocapped square antiprismatic nine-coordinate structure, in which the six coordinated atoms
(two N and four O) from the edta ligand and three water molecules are coordinated to the central Y III ion directly. The crystal of the Na[Y III(cydta)(H 2O) 2]·5H 2O complex belongs to the triclinic crystal system and
space group. The crystal data are as follows: a = 8.405(2) Å, b = 9.970(2) Å, c = 14.763(4) Å, α = 88.538(4)°, β = 76.193(4)°, γ = 88.100(4)°, V = 1200.6(5) Å 3, Z = 2, M = 580.31, D c = 1.605 g·cm −3, μ = 2.519 mm −1 and F(000) = 600. The final R and Rw are 0.0381 and 0.0911 for 4198 ( I > 2σ( I)) unique reflections, R and Rw are 0.0530 and 0.1041 for all 6186 reflections, respectively. The Y IIIN 2O 6 part in the [Y III(cydta)(H 2O) 2] − complex anion has a pseudo square antiprismatic eight-coordinate structure in which the six coordinated atoms (two N and
four O) from the cydta ligand and two water molecules are coordinated to the central YIII ion directly.
Original Russian Text Copyright ? 2005 by J. Wang, Y. Wang, Zh. H. Zhang, X. D. Zhang, J. Tong, X. Zh. Liu, X. Y. Liu, Y.
Zhang, and Zh. J. Pan
__________
Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 5, pp. 928–938, September–October, 2005. 相似文献
11.
LnCl 3 (Ln=Nd, Gd) reacts with C 5H 9C 5H 4Na (or K 2C 8H 8) in THF (C 5H 9C 5H 4 = cyclopentylcyclopentadienyl) in the ratio of 1 : to give (C 5H 9C 5H 4)LnCl 2(THF) n (orC 8H 8)LnCl 2(THF) n], which further reacts with K 2C 8H 8 (or C 5H 9C 5H 4Na) in THF to form the litle complexes. If Ln=Nd the complex (C 8H 8)Nd(C 5H 9C 5H 4)(THF) 2 (a) was obtained: when Ln=Gd the 1 : 1 complex [(C 8H 8)Gd(C %H 9)(THF)][(C 8H 8)Gd(C 5H 9H 4)(THF) 2] (b) was obtained in crystalline form. The crystal structure analysis shows that in (C8H8)Ln(C5H9C5H4)(THF)2 (Ln=Nd or Gd), the Cyclopentylcyclopentadieny (η5), cyclooctatetraenyl (η8) and two oxygen atoms from THF are coordinated to Nd3+ (or Gd3+) with coordination number 10. The centroid of the cyclopentadienyl ring (Cp′) in C5H9C5H4 group, cyclooctatetraenyl centroid (COTL) and two oxygens (THF) form a twisted tetrahedron around Nd3+ (or Gd3+). In (C8H8)Gd(C5H9C5H4)(THF), the cyclopentyl-cyclopentadienyl (η5), cyclooctatetraenyl (η8) and one oxygen atom are coordinated to Gd3+ with the coordination number of 9 and Cp′, COT and oxygen atom form a triangular plane around Gd3+, which is almost in the plane (dev. -0.0144 Å). 相似文献
12.
The infrared and Raman spectra of C 4H 8CHCOOH, C 4H 8CHCOOD, C 4H 8CDCOOH, C 4H 8CDCOOD and their sodium salts were studied and frequency assignments made; the ring puckering vibrations were observed in the Raman spectrum. The depolarisation values show the existence of a plane of symmetry, perpendicular to the ring compatible with a “bent” structure. 相似文献
13.
Density functional theory was used to study gas-phase reactions between the Cp 2*ZrMe + cations, where Cp* = C 5H 5 ( 1), Me 5Cp = C 5Me 5 ( 2), and Flu = C 13H 9 ( 3), and the ethylene molecule, Cp 2*ZrMe + + C 2H 4 → Cp 2*ZrPr + → Cp 2*ZrAllyl + + H 2. The reactivity of the Cp 2*ZrMe + cations with respect to the ethylene molecule decreased in the series 1 > 3 ≈ 2. Substitution in the Cp ring decreased the reactivity of the Cp 2*ZrMe + cations toward ethylene, in agreement with the experimental data on the comparative reactivities of complexes 1 and 3. The two main energy barriers along the reaction path (the formation of the C-C bond leading to the primary product Cp 2*ZrPr + and hydride shift leading to the secondary product Cp 2*Zr(H 2)Allyl +) vary in opposite directions in the series of the compounds studied. For Flu ( 3), these barriers are close to each other, and for the other compounds, the formation of the C-C bond requires the overcoming
of a higher energy barrier. A comparison of the results obtained with the data on the activity of zirconocene catalysts in
real catalytic systems for the polymerization of ethylene led us to conclude that the properties of the catalytic center changed
drastically in the passage from the model reaction in the gas phase to real catalytic systems. 相似文献
14.
用同步辐射对(C2H3Cl)2分子团簇进行了光电离研究,发现该团簇内部发生了离子-分子化学反应,生成了十分稳定的反应产物C4H5Cl^+,不再是varderWaals弱键络合物,本文对反主尖机理进行了初步探讨。 相似文献
15.
The complexes C 5H 5CuPR 3 (R = Me, Pr i), C 5H 5AuPR 3 (R = Me, Pr i), C 5Me 5CuPR 3 (R = Me, Pr i, Ph) and C 5Me 5AuPR 3 (R = Pr i, Ph) are prepared from [ClCuPR 3] n or ClAuPR 3 and LiC 5H 5 (TlC 5H 5) or LiC 5Me 5, respectively. According to the 1H and 13C NMR spectra, the cyclopentadienyl and pentamethylcyclopentadienylgold compounds are fluxional in solution. The X-ray crystal structure of C 5H 5AuPPr 3i has been determined at ?120°C. The gold atom is in a linear arrangement (PAuC(1) = 177.0(2)°) and primarily σ-bonded to the cyclopentadienyl ring which shows a weak “slip distortion” toward a η 3-mode of coordination. The complexes C 5R′ 5AuPR 3 (R′ = H, Me) and C 5Me 5CuPPr 3i react with 1-alkynes such as C 2H 2, HC 2Ph and HC 2CO 2Me to form alkinylgold and copper compounds R″C 2MPR 3. They have been characterized by IR, UV and NMR ( 1H, 13C, 31P) spectroscopy. 相似文献
16.
The 1H NMR spectra of C 2H 5InBr 2 · tmen ( 1) C 2H 5InI 2 · tmen ( 2) (tmen = N,N,N′,N′-tetramethylethanediamme) and [(C 6H 5) 4P][C 2H 5InI 3] ( 3) show only a broad singlet for the ethyl protons at 60 MHz. Spectra run at 400 MHz resolve these into a triplet + quartet for 1 and 3. The structure of each compound has been determined by X-ray crystallography; 1 and 2 are five-coordinate species, with InC 2N 2X (X = Br, I) nuclei, while 3 consists of [(C 6H 5) 4P] + cations and anions whose InCI 3 nucleus has C 3v, symmetry. 相似文献
17.
A time-of-flight mass spectrometer has been modified to study directly the time dependence of metastable decay processes by introducing a variable time delay between the ionization and extraction pulses and by providing a set of retarding plates and grids in the flight tube to select a single parent ion species for study and to resolve the peak into parent ion, daughter ion and daughter neutral components. The experimentally determined time dependence of the unimolecular decay process C 3H 8+ → C 3H 7+ + H is compared with previously published predictions of the quasiequilibrium theory of mass spectra. 相似文献
18.
合成了标题化合物[Mo(C9H6NO)2(O)2](C9H6NO=8-羟基喹啉),测定了化合物的晶体结构.晶体属单斜晶系,空间群Cc,a=13.372(3),b=9.421(2),c=13.554(3)A,β=109.71(3)°,V=1607.6(8)A3.结构由直接法解出,最后可靠性因子R=0.0473,Rw=0.062.Mo原子为6配位,位于八面体的中心.两个配体氧相互处于邻位,分别与8-羟基喹啉中的N原子处于对位. 相似文献
19.
C 2(a 3π u) disappearance rate constants of 1.44, 0.96, 0.0296, 0.0130 and < 10 ?6(x10 ?10cm 3s ?1) are reported for reactions with C 2H 4, C 2H 2, O 2, C 2H 6, and CH 4, respectively at 298 K. C 2(a 3π u) fragments are generated by multiphoton ArF excimer laser photodissociation at C 2H 2, and monitored by dye laser induced fluorescence. Arguments are presented which favor chemical reactions over the C 2(a 3π u) → (X 1σ +g) quenching channel. C 2 + C 2H 2 represents the one possible exception to the reactive channel. 相似文献
20.
Ohne Zusammenfassung
(C5H5FeSi1.5)4: A new quadrinuclear Fe-S cluster in a (C5H5FeS)4 matrix 相似文献
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