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991.
过渡金属配合物连接的多金属钒酸盐[Co(o-phen)]V2O6·H2O的水热合成和晶体结构 总被引:11,自引:1,他引:11
多金属氧酸盐 ( POMs)由于结构新奇 ,物理性能优异 ,在催化、医药、材料和光化学等领域有应用前景 ,而受到人们广泛关注 [1~ 8] .近年来 ,水热技术和有机指导剂的引入促进了 POMs的有机 -无机杂化材料如 [N( CH3) 4]5V18O4 6 [2 ]和 [V4 O10 ( phen) 2 ][3]等研究的迅速发展 .以上化合物多数仅以有机胺为抗衡离子或直接配位连接到无机骨架上 .而以过渡金属配合物为结构导向剂的合成策略 ,最近才引起人们的重视[9~ 11] .本文以钒酸盐 -过渡金属配合物作为研究体系 ,在水热条件下合成了一种未见文献报道的由新型过渡金属配合物连接的… 相似文献
992.
Joseph Grobe Duc Le Van Franz Immel Marianne Hegemann Bernt Krebs Mechtild Lge 《无机化学与普通化学杂志》1996,622(1):24-34
Reactive E = C(pp)π-Systems. XLII [1]. Novel Coordination Compounds of 2-(Diisopropylamino)-1-phosphaethyne: [{η4-(iPr2NCP)2}Ni{η2-(iPr2NCP)}], [(Ph3P)2Pt{η2-(iPr2NCP)}], and [Co2(CO)6{η2-μ2-(iPr2NCP)}] 2-(Diisopropylamino)-phosphaethyne iPr2N? C?P ( 2 ) reacts with the Ni(0)-complexes [Ni(1,5-cyclooctadiene)2] and [Ni(CO)3(1-azabicyclo[2.2.2]octane)], respectively, to give the novel complex [{η4-(iPr2NCP)2}Ni{η2-(iPr2NCP)}] ( 5 ), with the 1,3-diphosphacyclobutadiene derivative and 2 (side-on) as π-ligands. The molecular structure of 5 determined by X-ray diffraction on single crystals proves the spin systems and rotational barriers deduced from NMR-data (1H, 13C-, 31P). The PC distances of the four-membered ring of 1.817(2) and 1.818(2) Å – as expected – are considerably longer than the PC bond of the η2-coordinated phosphaalkyne 2 [1.671(2) Å]. – In the reactions of 2 with [(Ph3P)2Pt(C2H4)] or [Co2(CO)8] the ligand properties of 2 resemble those of alkynes affording the complexes [(Ph3P)2Pt{η2-(iPr2NCP)}] ( 7 ) with side-on coordinated 2 and [Co2(CO)6{η2-μ2-(iPr2NCP)}] with 2 acting as a 4e donor bridge in quantitative yield. In attempts to prepare copper(I) complexes of the aminophosphaalkyne 2 by reaction with CuCl or CuI the only isolable product formed in reasonable amounts under the influence of air and moisture is the 1 λ3, 3 λ5-diphosphetene (iPr2N) ( 10 ) (isolated yield: ca. 20%). The crystal structure analysis of 10 indicates a strong structural relationship to the diamino-2-phosphaallyl cation [Me(iPr2N)]+ ( 12 ), the 1,3-diphosphacyclobutadiene ligand (iPr2NCP)2 in the binuclear complex [{η1, μ2-(iPr2NCP)2}Ni2(CO)6] ( 3a ) as well as to the heterocycles (dme)2LiOE2′ (E′ = S, 11a ; E′ = Se, 11b ) prepared by Becker et al. [11b, 35]. 相似文献
993.
Four novel copper(Ⅱ) complexes have been synthesized,namely Cu(hfac)2NITPhNO2 (1),Cu(hfac)2NITPhCH3 (2),Cu(pfpr)2NITPhNO2,(3) and Cu(Pfpr)2NITPhCH3 (4),where hfac= hexafluoro-acetylacetonate,pfpr=pentafluoropropionate,NITR.=2-R-4,4,5,5-tetraniethyl-4,5-dihydro-1H-imidazolyl-1-oxyl-3-oxide.(R=4-nitrophenyl,4-methylphenyl).These complexes were rharicter-ized by elemental analyses,IR,electronic spectra and molar conductance.The temperature-dependent magnetic susceptibility of complexes 1 and 3 have been studied in the 4 300 K range,giving I he exchange integral J=10.56 cm-1 for complex 1 and J =-30.9 cm-1 for complex 3. 相似文献
994.
铜(II)-5-取代邻菲啰啉-二氧四胺大环三元体系的稳定性研究 总被引:1,自引:0,他引:1
The stability of copper (Ⅱ)-13-(2'-Hydroxy-3',5'-substituted benzyl)-1,4,8,11-tetraazacyclotetradecane-12, 14-dione(RTADO-14) binary complex compounds and of copper (Ⅱ)-5-substituted-1,10-phenanthrolines(R'TADO)-RTADO-14 ternary complex compounds was studied by means of pH titration method at 25.0±0.1 ℃ and I=0.1mol?dm-3KNO3. The formation constants of binary and ternary complexes were obtained. The structures of the binary and ternary complxes and the effects fo substituents on macrocyclic ligands and on R'Phen were also discussed. 相似文献
995.
Contributions to the Chemistry of Transition Metal Alkyl Compounds. 58 On 2-(Dimethylaminomethyl)ferrocenyl Compounds of Vanadium, Molybdenum, Tungsten, Thorium, and Uranium Earlier results according to which dimethylaminomethylferrocenyl groups (FcN) are able to form stable organometallic chelate compounds were confirmed by synthesis of the heterobimetallic chelate compounds (FcN)2VO · Li(acac) II , (FcN)MoO2(acac) III , (FcN)WOCl3 IV , (FcN)Th(acac)3 V , and (FcN)UO2(acac) VI from the corresponding metal acetylacetonates or oxidchlorides and (FcN)Li I . The new compounds were characterized by elemental analysis, the i.r., 1H-n.m.r., and electron spectra and by their effective magnetic moments. 相似文献
996.
Michael I. Rosenthal Anthony W. Czarnik 《Journal of inclusion phenomena and macrocyclic chemistry》1991,10(1):119-126
The ability of cyclodextrins to effect rapid transacylations of bound substrates has been well studied. One important difference between cyclodextrin and enzyme-mediated transacylation is the pH required. Because the pK
a of a cyclodextrin secondary-side hydroxyl group is about 12, transacylations are accelerated in the presence of cyclodextrin under basic conditions (pH > 10.5). In 1988, our group reported the synthesis of cyclodextrin with attached cyclen-Co(III) complexes; significant acceleration in the reaction withp-nitrophenyl acetate was observed only with the primary side derivative. Of course, metalloenzymes utilize M2+ and not M3+ catalytic centers; in addition, large rate accelerations in the transacylations of both activated and unactivated substrates have been observed previously in systems utilizing M2+ ions (e.g., Zn, Cu, Ni) as well as M3+ ions (e.g. Co, Ir, Cr). In this paper, we describe the ability of CD-cyclen-M2+ conjugates to transacylate activated esters, amides, and phosphates. In addition, the ability of the apoenzyme mimic to effect transacylations was examined. 相似文献
997.
The coordination around the thorium(IV) ion in aqueous perchlorate, chloride and nitrate solutions has been determined from large angle X-ray scattering measurements. In perchlorate solutions, where inner-sphere complexes are not formed, the first coordination sphere contains 8.0±0.5 water molecules with Th-H2O bond lengths of 2.485 Å. In chloride solutions inner-sphere complexes are formed, which lead to an increase in the coordination number. In nitrate solutions the nitrate ions are bonded as bidentate ligands to the thorium ion. The bond lengths are similar to those found in crystalline hydrates of thorium nitrate. The coordination numbers found for thorium(IV) in solution are compared with previously reported values for lower charged ions of similar size.On leave from Department of Inorganic Chemistry Royal Institute of Technology S-10044 Stockholm Sweden 相似文献
998.
Helmut G. Alt 《Russian Chemical Bulletin》1995,44(1):1-8
Ansa metallocene dichloride complexes of titanium, zirconium, and hafnium can be activated by methyl aluminoxane (MAO) to give excellent catalysts for the homogeneous polymerization of ethylene and propylene. The symmetry of the corresponding metaliocene dichloride complexes is essential for the stereospecific polymerization of propylene (isotactic, syndiotactic or atactic). The application of fluorenyl groups instead of cyclopentadienyl groups greatly increases the activity of the catalysts. The first ansa bis(fluorenyl) complexes of zirconium and hafnium, (C13H8-C2H4-C13Hs)MCl2 (M = Zr, Hf), have been prepared. It was found that after the activation by MAO the zirconium derivative demonstrates a very high activity. Several model complexes are presented in order to discuss the mechanism of the polymerization.This paper was presented at the INEOS-94 Workshop The Modern Problems of Organometallic Chemistry (Moscow, May 21–27, 1994).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 7–14, January, 1995. 相似文献
999.
A. A. Trifonov L. N. Zakharov M. N. Bochkarev Yu. T. Struchkov 《Russian Chemical Bulletin》1994,43(1):145-148
Ytterbium complexes, Cp2Yb(-2:2-DAB)Li(DME) (1) and CpYb(DAB)K(THF)2 (2), containing a bridging diazadiene ligand were prepared by the reaction of CpYbCl2(THF)3 with (DAB)Li2 (11) and (DAB)–K+ (12) (DAB = But-N=CH-CH=N-But). The structure of complex1 was established by X-ray diffraction analysis. The complex is binuclear: the Yb atom of the Cp2Yb fragment and the Li atom, which is bonded as well with the chelating DME molecule, are linked by the DAB ligand.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 148–151, January, 1994. 相似文献
1000.
M. S. Abu-Bakr H. M. Rageh E. Y. Hashem M. H. Moustafa 《Monatshefte für Chemie / Chemical Monthly》1994,125(11):1197-1205
Summary The ternary complex formation of copper(II) with gallic acid (gal) and 2-hydroxy nicotinic acid (hyna), 2-mercapto nicotinic acid (mena), salicylic acid (sa) or thiosalicylic acid (tsa) as a second ligand in a 1:1:1 molar ratio has been investigated in 40% (v/v) ethanol using spectrophotometric andpH titration methods. The solution equilibria of the ternary systems have been determined and the stability constants of the mixed complexes has been evaluated. Considering all parameters, the Cu-gal-sa ternary system was proved as a suitable, rapid, and sensitive spectrophotometric indicator for determining traces of copper.The ternary system containingsa obeysBeer's law up to 3.4 µg·ml–1 copper. The optimum range for the determination of copper (Ringbom) atpH 6.0 ranges from 0.63 to 1.74 µg·ml–1 of copper. The molar absorptivity of the ternary complex is 1.3×104l·mol–1·cm–1.
Untersuchungen anmixed-ligand — Komplexen von Kupfer(II) mit 3,4,5-Trihydroxybenzoesäure und Pyridincarbonsäuren und ihren C-Homologen
Zusammenfassung Die Bildung ternärer Komplexe von Kupfer(II) mit 3,4,5-Trihydroxybenzoesäure (gal) und 2-Hydroxynicotinsäure (hyna), 2-Mercaptonicotinsäure (mena), Salicylsäure (sa) oder Thiosalicylsäure (tsa) in einem molaren Verhältnis von 1:1:1 wurde mittels spektrophotometrischer und potentiometrischer Methoden in 40% (v/v) Ethanol untersucht. Die Lösungsgleichgewichte der termären Systeme und die Stabilitätskonstanten der gemischten Komplexe wurden bestimmt. Unter Berücksichtigung aller Parameter erwies sich das termäre System Cu-gal-sa als geeigneter schneller und empfindlicher Indikator zur Spurenanalyse von Kupfer.Dassa enthaltende ternäre System gehorcht demBeerschen Gesetz bis zu einer Kupferkonzentration von 3.4 µg·ml–1. Der optimale Bereich zur Bestimmung von Kupfer (Ringbom) beipH 6.0 erstreckt sich von 0.63 bis 1.74 µg Cu pro ml. Die molare Extinktion des ternären Komplexes beträgt 1.3×104l·mol·cm–1.相似文献