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1.
The synthesis and characterization of several new ruthenium complexes containing heterocyclic thiolate ligands are described. CpRu(PPh3)2Cl reacts with thiolate anions to give CpRu(PPh3)2SR, (1) [R = 2-mercaptobenzimidazolyl (a), 2-mercaptobenzothiazolyl (b), and 2-mercaptobenzoxazolyl (c)] in good yields. The CpRu(PPh3)-(CO)SR (2) complexes are obtained by treating (1) with CO gas in THF at room temperature. The one-pot reaction of CpRu(PPh3)2Cl, thiolate anions with chelate bisphosphine ligands (P–P), gave CpRu(P–P)SR where P–P = Ph2PCH2PPh2 (dppm) (3); Ph2PCH2CH2PPh2 (dppe) (4).  相似文献   

2.
Three new tin coordination compounds (4,4'-Hbipy)2[Sn2(C2O4)3] ( 1 ), (4,4'-H2bipy)[Sn(C2O4)2] ( 2 ), and SnCl2(4,4'-bipy) ( 3 ) were synthesized under hydro-(solvo-)thermal conditions and their crystal structures were determined by single-crystal X-ray diffraction. Compound 1 exhibits a ionic structure based on discrete [4,4'-Hbipy]+ cations and [Sn2(C2O4)3]2– anions. These two units are linked via N–H ··· O hydrogen bonds to form a pseudo-one-dimensional zigzag hydrogen-bonded chain. In compound 2 , four-coordinate Sn atoms form monomeric tin dioxalato complexes, which are connected to the doubly protonated [4,4'-H2bipy]2+ cations through N–H ··· O hydrogen bonded to give a one-dimensional zigzag hydrogen-bonded chain. Compound 3 forms a three-dimensional hydrogen-bonded network, in which 1[SnCl2(4,4'-bipy)] linear chains are interconnected to each other by C–H ··· Cl hydrogen bonding. The solid-state UV/Vis/NIR diffuse reflectance spectroscopy shows that three compounds are broadband semiconductors. The thermogravimetric analysis evidences the thermal stability of the three compounds up to 175, 201, and 246 °C, respectively.  相似文献   

3.
In order to shed light upon the nature and mechanism of 4f-3d magnetic exchange interactions, a series of binuclear complexes of lanthanide(3+) and chromium(3+) with the general formula [Ln(L)5(H2O)2Cr(CN)6]·mL· nH2O (Ln=La (1), Ce (2), Pr (3), Nd (4); x=5, y=2, m=1 or 2, n=2 or 2.5; L=2-pyrrolidinone) and [Ln(L)4(H2O)3Cr(CN)6] ·nH2O (Ln=Sm (5), Eu (6), Gd (7), Tb (8), Dy (9), Er (10); x=4, y=3, m=0, n= 1.5 or 2.0; L=2-pyrrolidinone) were prepared and the X-ray crystal structures of complexes 2, 6 and 7 were determined. All the compounds consist of a Ln-CN-Cr unit, in which Ln^3+ in a square antiprism environment is bridged to an octahedral coordinated Cr^3+ ion through a cyano group. The magnetic properties of the complexes 3 and 6-10 show an overall antiferromagnetic behavior. The fitting to the experimental magnetic susceptibilities of 7 give g= 1.98, J=0.40 cm^-1, zJ'= -0.21 cm^-1 on the basis of a binuclear spin system (Scd=7/2, Scr=3/2), revealing an intra-molecular Gd^3+-Cr^3+ ferromagnetic interaction and an inter-molecular antiferromagnetic interaction. For 7 the calculation of quantum chemical density functional theory (DFT), combined with the broken symmetry approach, showed that the calculated spin coupling constant was 20.3 cm^-1, supporting the observation of weak ferromagnetic intra-molecular interaction in 7. The spin density distributions of 7 in both the high spin ground state and the broken symmetry state were obtained, and the spin coupling mechanism between Gd^3+ and Cr^3+ was discussed.  相似文献   

4.
Secodecahedradiene 2a , featuring very proximate, perfectly syn‐periplanar and significantly pyramidalized C=C bonds, was synthesized as testing object for in‐plane(σ)‐homoconjugational electron delocalization, starting from the available pagodane 15b . The response of 2a (and in part its diester 2b ) – in π,π‐distance (average 3.08 Å), olefinic pyramidalization (average 26.9°), and π,π‐split (PE, 1.15 eV) intermediate between disecododecahedradiene 1a and 1,16‐dodecahedradiene 3a – to selected 4π‐reagents, electrophiles, and radicals was explored experimentally and by calculations. Intriguing multistep reaction sequences attest to the ease of competing stabilization pathways for the 3C/2e in‐plane homoconjugated cationic intermediates. PE, CV, and ESR measurements and calculations (DFT) characterize the radical cation generated from 2a as in‐plane homoconjugated 4C/3e‐species 2a .+, persistent in a Freon matrix, but only very shortly existent in solution (CIDNP). Consequently, NMR control of the two‐electron oxidation in SbF5/SO2ClF did not disclose the σ‐bis‐homoaromatic dication 4C/2e (see 2a 2 + ), but a bis‐allylic dication 75 as persistent species. In support of 2a 2 + as intermediate, evidence is presented for very limited kinetic protection offered by the secododecahedral framework to through H‐cage σ‐homoconjugated cations.  相似文献   

5.
Understanding the bonding in complexes X:BH3?nFn and X:BH3?nCln, for X=N2, HCN, LiCN, H2CNH, NF3, NH3 with n=0–3, is a challenging task. The trends in calculated binding energies cannot be explained in terms of any of the usual indexes, including π donation from the halogen lone pairs to the p(π) empty orbital on B, deformation energies, charge capacities, or LUMO energies, which are normally invoked to explain the higher Lewis acidity of BCl3 relative to BF3. The results of the high‐level G3B3 ab initio calculations reported in this study suggest that the interaction energies of these complexes are determined by a combination of at least three factors. These include the decrease in the electron‐accepting ability of B as a result of π donation by the halogen atom, the increase in the electron‐acceptor capacity of B due to deformation of the acid, and the large increase in the deformation energy of the acid with increasing halogen substitution. The dominant effects are those derived from the electronic effects of acid deformation. Deformation not only has direct energetic consequences, which are reflected in the large differences between dissociation (D0) and interaction (Eint) energies, but also leads to an enhancement of the intrinsic acidities of BH3?nFn and BH3?nCln moieties by lowering the LUMO energies to very different extents, consistent with the frontier orbital model of chemical reactivity. Although this lowering depends on both the number and the nature of the halogen substituents, binding energies do not systematically increase or decrease as the number of halogen atoms increases.  相似文献   

6.
The Raman and IR spectra of the complexes (CO)5CrSnCl2·THF (1), (CO)5WSnCl2·THF (2), (CO)5CrGeCl2·THF (3), (CO)5WGeCl2·THF (4), (CO)5CrSnCl2·2THF (5), and (CO)5WSnCl2·2THF (6) were measured and interpreted using quantum chemical calculations. Complexes 3 and 5 were characterized by X-ray analysis. The stretching vibrations of the CO groups in the spectra of solutions of complexes 1–6 obey the selection rules for C 4ν local symmetry. For the complexes containing 0 (type A), 1 (type B), and 2 (type C) THF molecules, a comparison was made of the calculated and experimental M$ \underline \cdots $ \underline \cdots EII bond lengths and energies, as well as the ν(CO) vibrational frequencies. The contribution of the π-component to the M$ \underline \cdots $ \underline \cdots EII bond decreases in the order A→B→C and leads to enhancement of the donor ability of the carbene-like ligand and to a slight elongation and weakening of this bond. An attempt to grow crystals of complex 6 in air unexpectedly resulted in a polynuclear complex [(CO)5WSn(Cl)(μ-OH)2SnCl2(μ-OH)]2·6THF, which was characterized by X-ray analysis and Raman spectroscopy.  相似文献   

7.
8.
<正> The title compounds have been synthesized and characterized by x-ray analysis. They are isomorphous, belonging to trigonal space group R3m,with crystallo-graphic parameters; (1)α =b =c= 13. 713(5) A ;α= β=γ=83. 66(3)°;V = 2535A3;Z = 2;DC=1. 80gcm-3;F(000) = 1358;M= 1373. 23;(2)α= b = c=13. 687(2) A;α = β = γ = 84. 27(1)°/;V = 2528. 0A3;Z = 2; Dc = 1. 81gcm-3; F (000)= 1362; M = 1377. 23;(3)α = b=c=13. 671(6) A ;α = β = γ=84. 12(3)°;V=2518A3;Z=2;DC = 1. 82 gcm-3;F(000)= 1364;Mr= 1376. 99.The structure of comp ound 2 has been determined with the final R= 0. 061 for 845 reflections with I≥3σ(Ⅰ).The three metal atoms are crystallographically equivalent because of the arbitrariness of orientation of the molecules,and in the sense of crystallography the molecule Fc2CoO(O2CCCl3)6(THF)3 is of C3vsymmetry with centered oxygen atom on the 3-fold axis. The atoms M,C(1~4),C1(1) and O(1) lie on the mirror. Three CC13 groups on one side the Fe2CoO plane and three terminal THF ligands are dynamically  相似文献   

9.
Two dinuclear lanthanide (Ln) complexes, formulated as [phen2Ln2(HCOO)4(HCOO)2-2x(NO3)2x](1, Ln=Gd and x=0.52; 2, Ln = Er and x = 0.90; phen = 1,10-phenanthroline), were synthesized and characterized. They are isostructural. The dinuclear molecule consists of two Ln 3+ bridged by four formate groups and chelated by phen and formate/nitrate ligands, and the Ln 3+ possesses a coordination environment of distorted tri-capped trigonal prism of LnO 7 N 2 . Both compounds behave as paramagnets between 2 and 300 K, but display two static field induced magnetic relaxation processes. One is slow and of spin-lattice type, and it results from the lifting of Kramer’s degeneracy of the ground-states of both Gd 3+ and Er 3+ , and the other is fast, and it might be spin-spin type.  相似文献   

10.
11.
The reactions of E powder (E=S, Se) with a mixture of Cr(CO)6 and Mn2(CO)10 in concentrated solutions of KOH/MeOH produced two new mixed Cr? Mn? carbonyl clusters, [E2CrMn2(CO)9]2? (E=S, 1 ; Se, 2 ). Clusters 1 and 2 were isostructural with one another and each displayed a trigonal‐bipyramidal structure, with the CrMn2 triangle axially capped by two μ3‐E atoms. The analogous telluride cluster, [Te2CrMn2(CO)9]2? ( 3 ), was obtained from the ring‐closure of Te2Mn2 ring complex [Te2Mn2Cr2(CO)18]2? ( 4 ). Upon bubbling with CO, clusters 2 and 3 were readily converted into square‐pyramidal clusters, [E2CrMn2(CO)10]2? (E=Se, 5 ; Te, 6 ), accompanied with the cleavage of one Cr? Mn bond. According to SQUID analysis, cluster 6 was paramagnetic, with S=1 at room temperature; however, the Se analogue ( 5 ) was spectroscopically proposed to be diamagnetic, as verified by TD‐DFT calculations. Cluster 6 could be further carbonylated, with cleavage of the Mn? Mn bond to produce a new arachno‐cluster, [Te2CrMn2(CO)11]2? ( 7 ). The formation and structural isomers, as well as electrochemistry and UV/Vis absorption, of these clusters were also elucidated by DFT calculations.  相似文献   

12.
A series of oxygen-deficient n=2 Ruddlesden-Popper phases, Sr3Fe2−xCoxO7−δ (0.25≤x≤1.75), were prepared by solid-state reactions. Temperature-dependent susceptibility and field-dependent magnetization data indicate that for x≥0.25 the dominant magnetic interactions are ferromagnetic. The onset of strong ferromagnetic interactions is evident at ∼200 K, and a transition to a cluster-glass state is observed for all compositions below ∼45 K. The temperature variation of resistivity for all the compounds shows variable-range hopping behavior with two different localization energy scales: one for T<40 K and another for T>80 K. Large negative magnetoresistance (the largest MR ∼−65% for x=0.25) is observed for all phases. The magnetic susceptibility, Mössbauer and X-ray absorption near-edge spectroscopy data indicate that the formal oxidation state of Fe is close to 4+. The key role of d delocalization in the Sr3Fe2−xCoxO7−δ system is compared to the Sr3Fe2−xMnxO7−δ series, where d localization dominates the properties.  相似文献   

13.
本文报道了连续二氧化碳激光敏化氧化CF_2HCl,CF_2==CF_2,CF_2==CFCL,CHCl_3,CHCl==CCl_2和CH_2==CH_2的反应,讨论了某些反应的机制。结果表明,激光敏化方法可以使不能直接吸收激光的反应物分子在气相中发生反应,并有可能产生卡宾。  相似文献   

14.
The coupled cluster singles and doubles method with perturbative treatment of triple excitations is applied to calculate the potentials of M(z)-X complexes (M = Cu, Ag, and Au; X = He, Ne, and Ar; and z = ±1). The bond functions and the basis set superposition errors are considered to obtain accurate interaction energies. The potential energy curves of all complexes are obtained. The vibrational energy levels and the spectroscopic parameters for these complexes are determined. The analytical potential energy functions are also fitted based on the potential energies.  相似文献   

15.
Two series of isostructural double An(IV) and guanidinium carbonates were obtained as single crystals of the formula [C(NH2)3]6[An(CO3)5] · nH2O (An = Th, U, Np, and Pu; n = 3 (I) and 4 (II)) and examined by X-ray diffraction. For the Pu(IV) complexes, a = 10.490(2) Å, b = 33.798(5) Å, c = 10.519(2) Å, β = 119.414(7)°, space group P21/c, Z = 4, R = 0.0369 (I) and a = 16.0895(18) Å, b = 13.1458(14) Å, c = 16.6951(18) Å, β = 108.116(6)°, space group C2/c, Z = 4, R = 0.0171 (II). Both series of complexes contain the anions [An(CO3)5]6?, in which the An atom is coordinated to five chelating bidenate carbonate ions. The coordination polyhedra of the An atoms are distorted bicapped square antiprisms. Within both the series, the An-O bond lengths decrease monotonically only for the sequence Th-U-Np. The average Np-O and Pu-O bond lengths in both tri- and tetrahydrates are virtually equal. The IR and electronic absorption spectra of the complexes obtained were studied. The absorption bands due to the f-f transitions experience bathochromic shifts in the spectra of the U4+ and Pu4+ carbonate complexes and hypsochromic shifts in the spectra of the Np4+ complexes.  相似文献   

16.
在空气中采用高温固相反应方法合成的17MO-(8-x-y)-75B2O3-xGd2O3(MLBEG,M-Mg,Ca,Sr,Ba)玻璃,在紫外光(λex=350nm)激发下发射蓝光和红光,在绿色光(λex=532nm)激发下发射红光,电子自旋共振谱研究表明玻璃体系中有Eu^2 离子存在,蓝色区的宽带发射是Eu^2 离子的5d-4f跃迁发射:红色区的窄带发射是Eu^3 离子的5Do-7FJ(J=1,2,3,4)跃迁发射,发现玻璃中的碱土金属离子对Eu^3 /Eu^2 离子的比例有很大影响,选择不同的碱土金属离子可以调节玻璃蓝色光和红色光的相对发射强度,MLBEG玻璃的发光性质可用于转换太阳能,增强植物的光合作用。  相似文献   

17.
对单电子溴键复合物H3C···Br—Y(Y=H, CCH, CN, NC, C2H3)的结构与性质进行了理论研究. 在B3LYP/6-311++G**水平上计算了稳定构型并做了频率分析. BSSE矫正的相互作用能(EBSSE)和NBO及AIM分析输入的波函数在MP2/6-311++G**水平下完成. 复合物H3C···Br—Y中, CH3(供电子体)自由基均提供一未成对电子与Br—Y中Br(受电子体)形成了单电子溴键, 此单电子溴键也具有“三电子”键的特征. 单电子溴键的形成导致甲基H的背向Y弯曲和Br—Y键的拉长及红移单电子溴键复合物的产生. 考察了电子受体中不同取代基, C(spn)-Br杂化及溶剂的存在对复合物作用的影响, 将单电子氢键, 单电子卤键和单电子锂键的作用强度做了对比, 进一步对Popelier提出的氢键体系中的前三个重要拓扑指标在单电子溴键体系中的重现性进行了探讨.  相似文献   

18.
Reaction of [Ru(trpy)Cl3] with quinolin-8-ol (HQ) yields [Ru(trpy)(Q)Cl]. Treatment of [Ru(trpy)(Q)Cl] with Ag+ in Me2CO–H2O (3:1) and MeCN gives [Ru(trpy)- (Q)(H2O)]+ and [Ru(trpy)(Q)(MeCN)]+, respectively, which were isolated as their perchlorate salts. A similar reaction in EtOH, in the presence of NaN3, yields [Ru(trpy)(Q)(N3)]. All complexes are diamagnetic (low-spin, d6, S = 0) and show many intense m.l.c.t. transitions in the visible region. They display a reversible RuII-RuIII oxidation in the -0.13-0.48 V versus s.c.e. range, followed by an irreversible RuIII-RuIV oxidation in the 0.46–1.08V versus s.c.e. range and three trpy-based reductions on the negative side of s.c.e. Chemical oxidation of [RuII(trpy)(Q)Cl] by Ce4+ gives [Ru(trpy)-(Q)Cl]+ which shows intense l.m.c.t. transitions in the visible region together with a weak ligand field transition in the lower energy region. The complex is one-electron paramagnetic (low-spin, d5, S=1/2) and shows a rhombic e.s.r. spectrum in MeCN–PhMe (1:1) solution at 77K. Chemical oxidation of [Ru(trpy)(Q)-(H2O)]+ results in the formation of a -oxo dimer, [{Ru(trpy)(Q)}2O]2+.  相似文献   

19.
采用空气中固相反应烧结法制备了一系列钙钛矿结构的(La1-xREx)2/3Sr1/3MnO3(RE=Y,Sm,Eu,Tb;x=0.1~0.5)稀土锰氧化物多晶样品.X射线衍射(XRD)分析表明掺杂RE部分替代La以后,样品的晶体结构为正交结构,空间群为Pbmm.在室温(300K)和液氮温度(77K)下分别测试了样品的磁性质,发现磁性质的改变与RE的掺入量以及RE的离子半径有关.在掺Tb的样品中明显存在巨磁电阻效应,磁场为2 T,温度为300和77 K分别测得(La0.6Tb0.4)2/3Sr1/3MnO3和(La0.7Tb0.3)2/3Sr1/3MnO3的磁电阻(MR)为80%和85%.随着Tb掺杂量的增加,在不同的磁场下,样品电阻-温度关系曲线的峰均向高温方向移动.  相似文献   

20.
Crystals of MCl2·2CONH3 (M = Cu2+, Mn2+) are synthesized from low-temperature water-formamide solutions and studied by crystal optical, single crystal X-ray diffraction, and infrared spectroscopy methods. The crystal structures of CuCl2·2CONH3 and MnCl2·2CONH3 are solved by direct methods and refined in the P1triclinic space group, R1= 0.043 and 0.038 for 501 and 686 reflections with F 0ÃΣ(F0) respectively. Unit cell parameters for Cu and Mn salts are: a = 3.705(1) Å and 3.685(1) Å, b = 7.049(2) Å and 7.136(2) Å, c = 7.375(2) Å and 7.779(2) Å, 6h =113.57(3)² and 117.17(2)², β = 96.17(3)² and 95.35(2)², γ = 94.85(3)² and 92.23(2)² respectively, Z= 1. In the studied crystal structures, MCl4O2 octahedra share Cl-Cl edges and form chains along the [100] direction. This direction corresponds to a morphological elongation of the obtained crystals and orientation of the maximum refractive index. The FT infrared spectra obtained in a range from 4000 cm?1 to 300 cm?1 are very close to the spectrum of liquid formamide, but exhibit better resolution of absorption bands.  相似文献   

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