排序方式: 共有21条查询结果,搜索用时 31 毫秒
1.
Liv Peters 《Journal of organometallic chemistry》2005,690(8):2009-2016
The new facially coordinating tripod ligand 3,3-bis(1-methylimidazol-2-yl)propionate (bmip) has been studied. A synthetic route to sodium 3,3-bis(1-methylimidazol-2-yl)propionate (Na[bmip], 2a) and its hydrochloride (Hbmip · 2HCl, 2b) is reported. The electronic properties of Hbmip were calculated by DFT methods and are compared to those of structurally similar bis(pyrazol-1-yl)acetic acids. The ligand was applied in the synthesis of the two tricarbonyl complexes [Re(bmip)(CO)3] (3) and [Mn(bmip)(CO)3] (4). Methyl 3,3-bis(1-methylimidazol-2-yl)propionate (bmipme) (1), which is the precursor of Hbmip, and the complexes [Re(bmip)(CO)3] (3) and [Mn(bmip)(CO)3] (4) were characterised by single crystal X-ray analysis. 相似文献
2.
3.
Sung Koo Kang Inhee Choi Jeongjin Lee Younghun Kim Jongheop Yi 《Current Applied Physics》2008,8(6):810-813
A variety of shapes, such as rod, tripod, -shape and cube, of Au nanocrystals were synthesized by employing different reaction conditions. The nanocrystals and their shape variation were characterized by transmission electron microscopy and UV–vis spectrophotometry. The evolution of shape was accomplished by controlling the parameters used in their synthesis, the concentration of reducing agent and surface capping agent. The effect of synthetic parameters on shape was explored, to determine suitable conditions for producing each shape of nanocrystals. Nanocrystals with different shapes have different plasmon bands in the visible region of the spectrum, which is a valuable property for sensor applications. 相似文献
4.
Sebastian Zarwell 《Tetrahedron letters》2008,49(25):4020-4025
The synthesis of a tripodal linker system with an adamantane core unit and an azobenzene headgroup is reported for the preparation of photochromic SAMs on gold surfaces. For the final Sonogashira-coupling of the ethynylene-linker precursor 4 with the p-iodo substituted azobenzene 6 model studies were required to optimize the coupling step in the presence of a diazene functionality. The photochromic properties of the photoswitch-linker-conjugate 1 were investigated in solution, and compared to the behavior of the precursor 6. 相似文献
5.
三(2-苯并咪唑甲基)胺-锌(Ⅱ)配合物模拟水解酶催化酯类水解研究 总被引:3,自引:0,他引:3
研究了三(2-苯并咪唑甲基)胺-锌(II)配合物作为水解酶模拟物催化乙酸对硝基苯酯(NA)水解动力学.结果表明,催化水解速率对NA及配合物浓度呈一级反应.水解速率遵循速率方程v=(kcat[Zn]+kOH[OH-]+k0)[NA].在298K,I=0.10mol/LKNO3,0.02mol/LTris,40%CH3CN水溶液中,二级反应速率常数kcat和kOH分别为0.12、1.45mol-1·L·S-1,k0为NA溶剂解的速率常数,其值为3.70×10-6s-1.与10%CH3CN溶液中的k0值相比,40%CH3CN水溶液中的k0值明显降低.本研究表明三(2-苯并咪唑甲基)胺-锌(II)配合物能有效地催化NA的水解.配合物对NA水解的催化作用受酸碱平衡控制.根据实验结果提出了催化反应的机理. 相似文献
6.
7.
Alternative Ligands. XXX Novel Tripod Ligands XM' (OCH2PMe2)n(CH2CH2PMe2)3?n (M' = Si, Ge; n = 0–3) for Cage Structures Attempts to prepare new tripod ligands XSi(OCH2PMe2)3 [X = CF3 ( 15 ), C6F5 ( 16 ), NMe2 ( 17 ), Cl ( 18 ), F ( 19 ), H ( 20 ), OEt ( 21 ), OMe ( 22 )] prove to be unsuccessful in spite of using different pathways, because the groups X undergo following reactions giving insoluble solids (polyadducts) or form inseparable mixtures, e. g. (RO)nSi(OCH2PMe2)4?n (R = Me, Et). In many cases Si(OCH2PMe2)4 ( 13 ) can be isolated from the reaction mixture. The syntheses of the ligands XSi(CH2CH2PMe2)3 [X = NMe2 ( 6 ), Cl ( 7 ), F ( 8 ), OMe ( 9 ), Vi ( 12 )], Si(OCH2PMe2)4 ( 13 ) und Me3GeOCH2PMe2 ( 14 ) are successful. The compounds MeSi(OCH2PMe2)2CH2CH2NMe2 ( 10 ) and MeSi(OCH2PMe2)2CH2CH2P(CF3)2 ( 11 ) with different donor groups are obtained in good yields. The preparative program includes the synthesis of the known representatives MeSi(OCH2PMe3)3 ( 1 ), MeSi(OCH2PMe2)2CH2CH2PMe2 ( 2 ), MeSi(OCH2PMe2)(CH2CH2PMe2)2 ( 3 ), MeSi(CH2CH2PMe2)3 ( 4 ) and MeGe(OCH2PMe2)3 ( 5 ). Important preparative steps are the substitution of M'Cl (M' = Si, Ge) by Me2PCH2O groups and the photochemically induced or base catalyzed addition of HNMe2, HPMe2 or HP(CF3)2 to SiVi functions. The novel compounds are characterized by analytical and spectroscopic (IR, NMR, MS) investigations. 相似文献
8.
Weiqiang Tan 《Journal of organometallic chemistry》2007,692(24):5395-5402
Phosphine-pyrazolyl based tripod ligands ROCH2C(CH2Pz)2(CH2PPh2) (R = H, Me, allyl; Pz = pyrazol-1-yl) were efficiently synthesized and characterized. Reactions of these ligands with [Ru(η6-p-cymene)Cl2]2 afforded complexes of the type [Ru(η6-p-cymene)Cl2](L) (6-8) in which the ligands exhibit κ1-P-coordination to the metal center. Complex [Ru(η6-p-cymene)Cl2{Ph2PCH2C(CH2OH)(CH2Pz)2}] (6) underwent chloride-dissociation in CH2Cl2/MeCN to give complex [RuCl(η6-p-cymene){κ2(P,N)-Ph2PCH2C(CH2OH)(CH2Pz)2}][Cl] (9). Complexes 6-9 demonstrated poor to moderate catalytic activity in the transfer hydrogenation of acetophenone. All these complexes were fully characterized by analytical and spectroscopic methods and their molecular structures were determined by X-ray crystallographic study. 相似文献
9.
Lin WuLi Liu Ru FangChao Deng Jun HanHongwen Hu Chen Lin Leyong Wang 《Tetrahedron letters》2012,53(28):3637-3641
A series of new P-bridgehead tripodal urea-based anion receptors 1-3 bearing phosphine oxide (PO) were synthesized and characterized. Their anion-binding ability was examined by UV-vis, 1H NMR, 31P NMR, and ESI-MS. The results revealed that receptors 1-3 showed good sensitivity, selectivity, and binding affinity for H2PO4− over NO3− and Br−, and among them receptor 2 showed the best binding affinity for H2PO4− over F−, Br−, CH3COO−, HSO4−, and NO3−. The Job plot experiments indicated that receptors 1-3 formed 1:1 stoichiometric complex with H2PO4−. 相似文献
10.
The tripodal N,N,O ligands 3,3-bis(3,5-dimethylpyrazol-1-yl)propionic acid (Hbdmpzp) (1) and 3,3-bis(pyrazol-1-yl)propionic acid (Hbpzp) (2) form the “missing link” between the well-known bis(pyrazol-1-yl)acetic acids and related ligands with a longer “carboxylate arm”. To illustrate the reactivity of this ligand, manganese and rhenium complexes bearing the ligand bdmpzp are reported. The complexes are compared to related compounds bearing other tripod ligands such as bis(3,5-dimethylpyrazol-1-yl)acetate (bdmpza) and 3,3-bis(1-methylimidazol-2-yl)propionate (bmip). Spectroscopic and structural data are used as a basis for comparison, as well as DFT calculations. Both ligands 1 and 2 and the complexes fac-[Mn(bdmpzp)(CO)3] (3) and fac-[Re(bdmpzp)(CO)3] (4) were characterised by X-ray crystallography. 相似文献