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1.
1 INTRODUCTION The studies of organotin compounds are of current interest owing to their wide range of applications such as biocides and thermal stabilizers for PVC plastic etc. Besides, the pharmaceutical properties such as the antitumor activities of organotin carboxylates have been investigated[1, 2]. In recent years, reports of synthesis and structural elucidation of various organotin carboxylic esters have appeared, revealing various new structural possibilities[3]. Since Kealy an…  相似文献   

2.
1 INTRODUTION The d10 configuration of Cd(II) permits a wide variety of coordination numbers and geometries[1~3]. In recent years, one-, two- and three-dimensional infinite supramolecular coordination assemblies of Cd(II) have been the subject of great interest owing to their potential applications in catalysis, optical properties, clathration, etc[4~8]. In fabricating the coordination assemblies, organic ligands as well as inorganic anions have been observed to control the structural di…  相似文献   

3.
1 INTRODUCTION Heterocyclic thiosemicarbazones as well as their metal complexes have been attracting considerable interest due to their biological activities, such as antiviral, antibacterial, antimalarial, antifungal, and antitumoral activities[1~5]. This prompted us to carry out structural studies of these complexes to provide a basis for understanding their behaviors in living systems. Although quite a number of investigations on the 2-heterocyclic thiosemicarbazones have ap- peared[6…  相似文献   

4.
1 INTRODUCTION The design and construction of coordination fra- meworks are of great interest due to their intriguing structural motifs and potential applications as func- tional materials[1~4]. Many interesting fra-meworks with different dimensionalities have been obtained through self-assembly of selected metal centers and tailored ligands[5, 6]. Among them, dicarboxylate ligands, such as terephthalate[7, 8], isophthalate[9~12] and succinate[13, 14], are often used as bridges to bond m…  相似文献   

5.
1 INTRODUCTION Polyoxometalate anions are a broad class of dis- crete metal-oxide compounds MxOyn–, which are of both fundamental and practical interest in a range of areas, including catalysis, biochemistry, medicine and solid state devices[1~6]. Recently, the structural chemistry of vanadium oxides in combination with secondary metal-ligand cations has attracted much attention[7~17]. These hybrid materials manifest the structural influences both of coordination preferen- ces of the sec…  相似文献   

6.
1 INTRODUCTION The chemistry of polyoxometalates continues to attract interest as a result of their realized and potential applications in diverse fields, such as cata- lysis, analysis, biochemistry, medicine and material science[1~3]. In the past few …  相似文献   

7.
1 INTRODUCTION Polyoxomolybdates have been of great interest due to their unique structural varieties, associated multitude of properties and applications as catalysis, medicine and material[1, 2]. One of the most impor- tant aspects is the synthesis and investigation of the materials on polyoxomolybdates containing organo- metallic groups[3~5]. Such materials can provide molecular models for heterogeneous catalysis and display cooperative effects or bifunctional catalytic activity[6]. O…  相似文献   

8.
1 INTRODUCTION Polyoxometalates are the unique metal-oxygen clusters composed of transition metals in groups V and VI (Mo, W, V, Nb, Ta) in a high oxidation state showing a large structural varieties as well as inte- resting physical and chemical properties in diverse fields including catalysis, analytical chemistry, nanotechnology, chemical sensing, biochemical and geochemical processes, medicine and materials science[1~5]. Recently, there has been increasing interest in the synthesis…  相似文献   

9.
1 INTRODUCTION There is considerable interest in the study of Schi- ff-base complexes containing sulfur and complexes of amino acid Schiff-bases[1~8] due to their antiviral, anticancer and antibacterial activities. Furthermore, zinc, as one of the most important trace elements, plays a versatile role in biological systems due to its structural and catalytic roles in enzymes[9, 10]. There- fore, many efforts have been expended on the study of synthetic analogues of zinc enzymes in the hope…  相似文献   

10.
IntroductionGlucuronides are well known as phaseⅡ metabo-lites of xenobiotics, usually of phenols, alcohols, andacids, as well as those of hydroxylamines and tertiaryamine[1]. There is a growing interest in identifyingsuch metabolites and in establishing…  相似文献   

11.
1 INTRODUCTION In the last decade, we have been interested in the synthesis of [PPh4][(h5-C5Me5)MS3] (M = Mo, W)[1, 2] , Whose organometallic trisulfido anions show high reactivity towards various transition metals[3~6] . We once reported that the reaction of [PPh4][(h5-C5Me5)WS3] with CuBr in CH3CN afforded a double incomplete-cubane cluster [PPh4]2[(h5-C5Me5)WS3(CuBr)3]2[3], while the analogous reaction of [PPh4][(h5-C5Me5)WS3] with CuBr in CHCl3 gave rise to a 揻our-…  相似文献   

12.
(R~8P)~4-nCoX~n(R=Ph,Et 等;X=C,B=1,2)与Na~E~x(E=S,Se;X=1,2)在DMF或DMF/乙醇介质中反应得到了一系列六核钴的原子簇化合物Co~6(μ~3-E)~8(PR~3)~6.这些化合物含有正规的或畸变的Co~6八面簇骼.化合物可以用I~2氧化生成正一价的簇合物而不改变簇骼的几何构型,反达来,正一价的簇合物也可以被苊烯钠还生成中性的簇合物.本文还研究了这些化合物的电化学性质并提出了氧化还原反应的电子传递过程.  相似文献   

13.
The syntheses, crystal structures determined by single-crystal X-ray diffraction, and characterizations of new Mo(6) cluster chalcobromides and cyano-substituted compounds with 24 valence electrons per Mo(6) cluster (VEC = 24), are presented in this work. The structures of Cs(4)Mo(6)Br(12)S(2) and Cs(4)Mo(6)Br(12)Se(2) prepared by solid state routes are based on the novel [(Mo(6)Br(i)(6)Y(i)(2))Br(a)(6)](4)(-) (Y = S, Se) discrete units in which two chalcogen and six bromine ligands randomly occupy the inner positions, while the six apical ones are fully occupied by bromine atoms. The interaction of these two compounds with aqueous KCN solution results in apical ligand exchange giving the two first Mo(6) cyano-chalcohalides: Cs(0.4)K(0.6)(Et(4)N)(11)[(Mo(6)Br(6)S(2))(CN)(6)](3).16H(2)O and Cs(0.4)K(0.6)(Et(4)N)(11)[(Mo(6)Br(6)Se(2))(CN)(6)](3).16H(2)O. Their crystal structures, built from the original [(Mo(6)Br(i)(6)Y(i)(2))(CN)(a)(6)](4)(-) discrete units, will be compared to those of the two solid state precursors and other previously reported Mo(6) cluster compounds. Their redox properties and (77)Se NMR characterizations will be presented. Crystal data: Cs(4)Mo(6)Br(12)S(2), orthorhombic, Pbca (No. 61), a = 11.511(5) A, b = 18.772(5) A, c = 28.381 A (5), Z = 8; Cs(4)Mo(6)Br(12)Se(2), Pbca (No. 61), a = 11.6237(1) A, b = 18.9447(1) A, c = 28.4874(1) A, Z = 8; Cs(0.4)K(0.6)(Et(4)N)(11)[(Mo(6)Br(6)S(2))(CN)(6)](3).16H(2)O, Pm-3m (No. 221), a = 17.1969(4) A, Z = 1; Cs(0.4)K(0.6)(Et(4)N)(11)[(Mo(6)Br(6)Se(2))(CN)(6)](3).16H(2)O, Pm-3m (No. 221), a = 17.235(5) A, Z = 1.  相似文献   

14.
The reaction of a trinuclear rhenium sulfide cluster compound Re3S7Cl7 with dimethylphenylphosphine and CuX2 (X = Cl or Br) or CuX (X = Cl, Br, or I) formed tetranuclear cluster complexes [(Ph3P)2N][Re3(CuX)(mu3-S)4Cl6(PMe2Ph)3] (X = Cl, Br, or I). Their solutions have the characteristic intense blue color with visible spectral bands near 600 nm. Single-crystal X-ray structures show that three mu-S atoms in the intermediate trinuclear rhenium complex coordinate to a copper atom, forming elongated tetrahedral structures in which Re-Cu bonding interaction is negligible (Re-Cu distances are 3.50 to approximately 3.54 A as compared with Re-Re distances ranging from 2.69 to 2.81 A).  相似文献   

15.
16.
The aminobis(phosphonite) PhN(P(OC6H4OMe-o)2)2 (PNP; 1) reacts with 2 equiv of CuI to give a binuclear complex, Cu2(mu2-I)2(NCCH3)2(mu-PNP) (2), whereas similar reactions with CuCl and CuBr furnish tetranuclear "ladder"-type complexes, Cu4(mu2-X)2(mu3-X)2(mu-PNP)2 (3, X = Cl; 4, X = Br), in excellent yield. The complex 2 when heated under vacuum turns into the tetranuclear complex 5 in a reversible fashion. Similarly, the complexes 3 and 4 on dissolution in CH3CN dissociate reversibly into the corresponding binuclear complexes from which the tetrameric complexes can be readily regenerated. Treatment of 2 with excess of pyridine produces the heterosubstituted derivative, Cu2(mu2-I)2(C5H5N)2(mu-PNP) (6). The interaction of 2 with 2,2'-bipyridine in 1:1 and 1:2 ratios produces the mono- and disubstituted derivatives, Cu2(mu2-I)I(C10H8N2)(mu-PNP) (7) and [Cu2(mu2-I)(C10H8N2)2(mu-PNP)]I (8), respectively. The chloro and bromo analogues of 7 are prepared by treating the tetranuclear derivatives 3 and 4 with 2,2'-bipyridine. Reaction of 2 with 4,4'-bipyridine in the presence of AgOTf gives the cationic complex [Cu4(NCCH3)4(C10H8N2)2(mu-PNP)2](OTf)4 (9), whereas the complex [Cu2(NCCH3)2(mu-PNP)2](OTf)2 (10) was obtained from the reaction of 2 with 1 equiv of 1 and AgOTf. The reactions of 3 and 4 with 2 equiv of 4,4'-bipyridine in acetonitrile afford one-dimensional copper(I) coordination polymers [Cu2(mu2-X)2(mu-PNP)(C10H8N2)]n (13, X = Cl; 14, X = Br). The molecular structures of 2-4, 6-8, 12, and 14 are confirmed by X-ray crystallography.  相似文献   

17.
New complexes (Bu(4)N)(2)[Mo(6)X(8)(n-C(3)F(7)COO)(6)] (X = Br, I) display extraordinarily bright long-lived red phosphorescence both in solution and solid phases, with the highest emission quantum yields and the longest emission lifetimes among hexanuclear metal cluster complexes of Mo, W and Re, hitherto reported.  相似文献   

18.
An example of a direct axial interaction of a platinum(II) atom with a Mo(2) core through a uniquely designed tridentate ligand 6-(diphenylphosphino)-2-pyridonate (abbreviated as pyphos) is described. Treatment of PtX(2)(pyphosH)(2) (2a, X = Cl; 2b, X = Br; 2c, X = I) with a 1:1 mixture of Mo(2)(O(2)CCH(3))(4) and [Mo(2)(O(2)CCH(3))(2)(NCCH(3))(6)](2+) (3a) in dichloromethane afforded the linear trinuclear complexes [Mo(2)PtX(2)(pyphos)(2)(O(2)CCH(3))(2)](2) (4a, X = Cl; 4b, X = Br; 4c, X = I). The reaction of [Mo(2)(O(2)CCMe(3))(2)(NCCH(3))(4)](2+) (3b) with 2a-c in dichloromethane afforded the corresponding pivalato complexes [Mo(2)PtX(2)(pyphos)(2)(O(2)CCMe(3))(2)](2) (5a, X = Cl; 5b, X = Br; 5c, X = I), whose bonding nature is discussed on the basis of the data from Raman and electronic spectra as well as cyclic voltammograms. The linear trinuclear structures in 4b and 5a-c were confirmed by NMR studies and X-ray analyses: 4b, monoclinic, space group C2/c, a = 34.733(4) ?, b = 17.81(1) ?, c = 22.530(5) ?, beta = 124.444(8) degrees, V = 11498(5) ?(3), Z = 8, R = 0.060 for 8659 reflections with I > 3sigma(I) and 588 parameters; 5a, triclinic, space group P&onemacr;, a = 13.541(3) ?, b = 17.029(3) ?, c = 12.896(3) ?, alpha = 101.20(2) degrees, beta = 117.00(1) degrees, gamma = 85.47(2) degrees, V = 2599(1) ?(3), Z = 2, R = 0.050 for 8148 reflections with I > 3sigma(I) and 604 parameters; 5b, triclinic, space group P&onemacr;, a = 12.211(2) ?, b = 20.859(3) ?, c = 10.478(2) ?, alpha = 98.88(1) degrees, beta = 112.55(2) degrees, gamma = 84.56(1) degrees, V = 2433.3(8) ?(3), Z = 2, R = 0.042 for 8935 reflections with I > 3sigma(I) and 560 parameters; 5c, monoclinic, space group P2(1)/n, a = 13.359(4) ?, b = 19.686(3) ?, c = 20.392(4) ?, beta = 107.92(2) degrees, V = 5101(2) ?(3), Z = 4, R = 0.039 for 8432 reflections with I > 3sigma(I) and 560 parameters.  相似文献   

19.
Resonance Raman spectra of the cubic metal-halide complexes having the general formula [M(6)X(8)Y(6)](2)(-) (M = Mo or W; X, Y = Cl, Br, or I) are reported. The three totally symmetric fundamental vibrations of these complexes are identified. The extensive mixing of the symmetry coordinates that compose the symmetric normal modes expected in these systems is not observed. Instead the "group-frequency" approximation is valid. Furthermore, the force constants of both the apical and face-bridging metal-halide bonds are insensitive to the identity of either the metal or the halide. Raman spectra of related complexes with methoxy and benzenethiol groups as ligands are reported along with the structural data for [Mo(6)Cl(8)(SPh)(6)][NBu(4)](2). Crystal data for [Mo(6)Cl(8)(SPh)(6)][NBu(4)](2) at -156 degrees C: monoclinic space group P2(1)/c; a = 12.588(3), b = 17.471(5), c = 20.646(2) ?; beta = 118.53(1) degrees, V = 3223.4 ?(3); d(calcd) = 1.664 g cm(-)(3); Z = 2.  相似文献   

20.
Various complexes of the types [Mo(DAD)(CO)(3)L] (L = CO, MeCN, MeOH, THF, DMSO, DMF, Me(2)CO, EtOAc, THT, Im(H), Im(1), tBuNC, nBu(3)P), (ER(4))[Mo(DAD)(CO)(3)X] (ER(4) = NEt(4)(+); X(-) = Cl(-), Br(-), I(-), NCS(-), CN(-) and ER(4)(+) = PPh(4)(+); X(-) = N(3)(-)), and (ER(4))[{Mo(DAD)(CO)(3)}(2)(μ-X)] (ER(4)(+) = NEt(4)(+); X(-) = CN(-), OAc(-) and ER(4)(+) = PPh(4)(+); X(-) = N(3)(-); DAD = N,N'-bis(2,6-dimethylphenyl)butane-2,3-diimine) were prepared by ligand exchange from cycloheptatriene molybdenum tricarbonyl. A total of 19 crystal structures were determined, including unprecedented structural characterization of molybdenum(0) coordination by dimethyl sulfoxide (DMSO), methanol, ethyl acetate (EtOAc), acetone, and N,N-dimethylformamide (DMF). Correlation of (13)C NMR shifts with the complex geometry suggests a direct ligand-ligand interaction between DAD and O-bonded coligands with C═O and S═O double bonds, such as EtOAc, Me(2)CO, DMF, and DMSO. Unexpectedly, the solvatochromic properties of these tricarbonyl complexes [Mo(DAD)(CO)(3)L] are unfavorable for the determination of Kamlet-Taft parameters of the corresponding solvent L. Contrastingly, the UV/vis absorption of [Mo(DAD)(CO)(4)] is strongly correlated with the Kamlet-Taft parameter π*, which is shown for 22 solvents, including seven room temperature ionic liquids.  相似文献   

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