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131.
Fadila Balegroune Pierre Braunstein Laurent Douce Yves Dusausoy Daniel Grandjean Michael Knorr Martin Strampfer 《Journal of Cluster Science》1992,3(3):275-296
The reactions of K[Fe{Si(OMe)3}(CO)3(PY)][PY=Ph2PCH2C(O)Ph, Ph2PCH2C(O)[(-C5H4)FeCp] (Cp=5-C5H5), Ph2P(CH2)2CN] with CdCl2·2.5H2O, ZnX
2 (X=Cl, I) or InCl3 afforded Fe-Cd-Fe or Fe-M(-X)2
M-Fe (M=Cd, Zn, In;X=Cl, I) and Fe-InCl2 complexes. Some of them contain an unusual and labile -2-SiO alkoxysilyl bridge which may be associated with a bridging mode for the ketophosphine ligand (first such example structurally established), thus providing original results in bimetallic chemistry on the intramolecular coordination of oxygendonor functions ofchemically different hemilabile ligands firmly attached to a neighboring metal center. The structures of the trinuclear complex (3), of the chlorobenzene solvate of the tetranuclear complex (4a·C6H5Cl) and of [mer-(OC)3{(EtO)3Si} (4e) have been determined by X-ray diffraction. Crystals of 3 are orthorhombic, space groupPbcn, witha=19.010(4),b=11.766(5),c=26.998(7)Å, andZ=4. Crystals of4a·C6H5Cl are monoclinic, space groupC2/c witha=22.455(3),b=17.680(2),c=16.627(4)Å, =90.80(4)°, andZ=4. Crystals of4e are monoclinic, space groupC2/c witha=25.392(5),b=18.554(6),c=16.28(1)Å, =120.73(3)°, andZ=4. The structures were solved using direct methods and Fourier difference techniques and refined by blocked full-matrix least squares toR=0.035 (R
w
=0.049) for 2719 observed reflections, toR=0.042 (R
w
=0.056) for 3082 observed reflections, and toR=0.057 (R
w
=0.075) for 1850 observed reflections for3, 4a·C6H5Cl and4e, respectively. The Fe-Zn complexes (9a), (9b) and (9c) were prepared and characterized by spectroscopic methods.Part 21 in the Series: Complexes with Functional Phosphines. Part 20: P. Braunstein, S. Coco Cea, A. DeCian, and J. Fischer (1992).Inorg. Chem.
31, 4203. 相似文献
132.
通过由Fe3(CO)12、RSH和Et3N所形成的[(μ-CO)(μ-RS)Fe2(CO)6]Et3NH于室温下分别与对或间苯二甲酰氯的原位反应,首次合成6个结构新颖的苯二甲酰基桥联铁硫配合物[(μ-RS)·Fe2(CO)6]2(μ-p-OCC6H4CO-p-μ)(R=Et,n-Bu,t-Bu)以及[(μ-RS)Fe2(CO)6]2(μ-m-OCC6H4CO-m-μ)(R=n-Pr,n-Bu,t-Bu)。经元素分析、IR光谱及1HNMR表征了它们的结构,并讨论了产物的生成过程。此外,还提出了合成对苯二甲酰氯的一种新方法。 相似文献
133.
Dinuclear Silylene Bridged Cyclopentadienylrhodiumbis(ethene) Complexes, Photochemical Reaction with Benzene Derivatives, and Selective Inclusion of Methylcyclopentane into the Crystal Lattice of [Me2Si{3-But-C5H3Rh(C2H4)2}2] By reaction of [{(C2H4)2RhCl}2] with Na2[Me2Si(C5H4)2] or with Li2[Me2Si(3-But-C5H3)2] in THF the dinuclear silylene bridged complexes [Me2Si{C5H4Rh(C2H4)2}2] 1 and [Me2Si{3-But-C5H3Rh(C2H4)2}2] 2 , respectively, were synthesized. Due to the asymmetric substitution of the five-membered rings and their hindered rotation around the Si? C axes, 2 is formed as three isomers. The X-ray structure analysis of 2 obtained from hexane reveals the selective inclusion of methylcyclopentane, the content of which in the solvent is about 17%, into the crystal lattice. UV irradiation of 1 in hexane in the presence of benzene causes elimination of the ethene ligands yielding the μ-η3:η3 benzene complex [Me2Si(C5H4Rh2)2C6H6] which cannot be separated from unreacted 1 . However, separation is possible in case of the hexamethylbenzene compound 4 analogous with 3 . 相似文献
134.
一些砷、锑的配合物具有抗癌、杀菌等生物功能[1,2],可用于药物研究.近年来,用砷剂(主要是三氧化二砷)治疗急性早幼粒细胞白血病(APL),具有缓解率高而复发率低的优点,引起世人的关注.因砒霜中仅含氧和砷,起药物作用的实际是砷(Ⅲ).因此,选择有生物功能的配体合成新型砷配合物对治疗白血病可能有一定药物作用.由于砷的无机盐易水解,故合成砷的生物配合物很困难,对砷配合物的研究也很少报道 [3-7].本文用异烟肼、L-苯丙氨酸和三碘化砷通过室温固相反应合成了两种未见报道的砷配合物,经元素分析,紫外光谱,X-射线粉末衍射,中、远红外光谱和热重差热分析确定了配合物的化学组成,并对配合物的抑菌活性进行了研究. 相似文献
135.
Mohamed M.?KhalilEmail author Mohamed?Taha 《Monatshefte für Chemie / Chemical Monthly》2004,135(4):385-395
Summary. The formation equilibria for the binary complexes of CoII, NiII, CuII, ZnII, CdII, MnII, PbII, ThIV, UO2II, and CeIII with tricine and for the ternary complexes involving some -amino acids (glycine, -alanine, proline, serine, asparagine, and aspartic acid) were investigated using pH-metric technique. The formation of binary and ternary complexes was inferred from the pH-metric titration curves. It was deduced that tricine acts as a primary ligand in the ternary complexes involving the monocarboxylic amino acids (glycine, -alanine, proline, serine, and asparagine), whereas it behaves as a secondary ligand in the ternary systems containing the dicarboxylic aspartic acid. The ternary complex formation was found to take place in a stepwise manner. The stability constants of the complexes formed in aqueous solutions were determined potentiometrically under the experimental conditions (t=25°C, I=0.1moldm–3 NaNO3). The order of stability of the ternary complexes in terms of the nature of the amino acids is investigated and discussed. The values of log K for the ternary complexes have been evaluated and discussed. Evaluation of the effects of ionic strength and temperature of the medium on the stability of the ternary system MII-tricine--alanine (MII=CoII, NiII, and CuII) has been studied. The thermodynamic parameters were calculated and discussed. 相似文献
136.
In this review anti-metatype antibodies are described invoking new principles in immunoassay development. Anti-metatype antibodies are immunological reagents specific for the conformation of the liganded antibody active site which do not interact with bound ligand or unliganded antibody. Relationships between anti-metatype antibody reactivity and the ligand-induced conformational state of monoclonal antibodies are reviewed with emphasis on the fluorescein hapten as a small molecule model system. One characteristic result of the interaction of anti-metatype antibodies with liganded antibodies is a significant delay in the dissociation rate (k2) of the ligand bound within the primary immune complex. The latter is an important consideration for assay development. Polyclonal and monoclonal anti-metatype antibody reagents are characterized in terms of their differential effects on the ligand dissociation rate. Anti-metatype antibody reactivity is further discussed in terms of protein-protein specificity patterns and relative interactions with idiotype-family members, structural derivatives, and site-specific mutants. Incorporation of principles inherent in the anti-metatype concept and their application to assay development are summarized.Abbreviations D2O
deuterium oxide
- Fab
50 kd antibody fragment containing VHCH1 + VLCL domains
- FITC(I)
fluorescein isothiocyanate (isomer I)
- Fv
26 kd fragment of the antibody molecule containing the variable domains of the H and L chains
- Ig
immunoglobulin
- IgG
immunoglobulin G with a mol. wt. of 150 kd.
- IgM
immunoglobulin M with a mol. wt. of 106d
- Id
idiotype
- Ka
antibody affinity (k1/k2) in M–1
- k1
second order rate of ligand association in M–1s–1
- k2
first order rate of ligand dissociation in s–1
- KD
dissociation constant or the reciprocal of the affinity constant (1/Ka)
- Mab
monoclonal antibody
- Met
metatype
- NMR
nuclear magnetic resonance
- SCA
single chain Fv derivative containing a synthetic linker between the two variable domains
- VH
variable domain of the antibody H chain
- VL
variable domain of the antibody L chain 相似文献
137.
Armando J. L. Pombeiro Raymond L. Richards 《Monatshefte für Chemie / Chemical Monthly》1992,123(8-9):749-756
Summary Reactions oftrans-[M(N2)2(dppe)2] (A;M=Mo, W;dppe=Ph
2PCH2CH2PPh
2) with ethyldiazoacetate, N2CHCOOEt, yield the bisdiazoalkane speciestrans-[M(N2CHCOOEt)2(dppe)2], upon simple replacement of the dinitrogen ligand by ethyldiazoacetate. However, diazomethane, N2CH2, reacts withA with loss of N2 to give products which we tentatively formulate as containing methylene ligands,trans-[M(CH2)2(dppe)2].
Herstellung von Bisdiazoalkan- und ähnlichen Komplexen aus den Reaktionen von Diazoverbindungen mit Distickstoffkomplexen des Typstrans-[M(N2)2(Ph 2PCH2CH2PPh 2)2] mitM=Mo oder W
Zusammenfassung Die Reaktion vontrans-[M(N2)2(dppe)2] (A:dppe=Ph 2PCH2CH2PPh 2 undM=Mo oder W) mit Ethyldiazoacetat, N2CHCOOEt, ergab nach einfachem Austausch des Distickstoffliganden mit Ethyldiazoacetat die Bisdiazoalkanetrans-[M(N2CHCOOEt)2(dppe)2]. Diazomethan (N2CH2) hingegen reagierte mitA unter Verlust von N2 zu Produkten, die tentativ alstrans-[M(CH2)2(dppe)2] mit Methylenliganden formuliert wurden.相似文献
138.
The magnetic interactions in a new series of isostructural imino nitroxide radical lanthanide(III) complexes, [Ln(hfac)3(IM2py)] (Ln = Gd–Yb: IM2py = 2-(2′-pyridyl)-4,5-dihydro-4,4,5,5-tetramethyl-1H-imidazoline-1-oxy; hfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione), are examined by considering the intrinsic paramagnetic contribution of the Ln(III) ion from the corresponding [Ln(hfac)3(pybzim)] with a diamagnetic pybzim(2-(2-pyridyl)benzimidazole) ligand; the Ln(III)–IM2py interaction being antiferromagnetic for the 4f7 to 4f13 Ln(III) complexes and negligibly small for the other complexes. This series is the first example reverse to the previous cases for the series of Ln–Cu or Ln–aminoxyl(NIT) radical (4,5-dihydro-4,4,5,5-tetramethyl-1H-imidazoline-3-oxide-1-oxy) complexes, other than only a few examples of semiquinone Ln complexes. This reverse nature of the magnetic interaction, as compared with the NIT complexes, validates the empirical approach by O. Kahn et al. [Inorg. Chem. 38 (1999) 3692; J. Am. Chem. Soc. 122 (2000) 3413] in the spin-coupled systems for a series of Ln(III) complexes. 相似文献
139.
Michelini Mdel C Russo N Alikhani ME Silvi B 《Journal of computational chemistry》2004,25(13):1647-1655
The Density functional theory has been applied to characterize the structural features of Mo(1,2)-NH(3),-C(2)H(4), and -C(2)H(2) compounds. Coordination modes, geometrical structures, and binding energies have been calculated for several spin multiplets. It has been shown that in contrast to the conserved spin cases (Mo(1,2)-NH(3)), the interaction between Mo (or Mo(2)) and C(2)H(4) (or C(2)H(2)) are the low-spin (Mo-C(2)H(4) and -C(2)H(2)) and high-spin (Mo(2)-C(2)H(4) and -C(2)H(2)) complexes. In the ground state of Mo(1,2)-C(2)H(4) and -C(2)H(2), the metal-center always reacts with the C-C center. The spontaneous formation of the global minima is found to be possible due to the crossing between the potential energy surfaces (ground and excited states with respect to the metallic center). The bonding characterization has been performed using the topological analysis of the Electron Localization Function. It has been shown that the most stable electronic structure for a pi-acceptor ligand correlates with a maximum charge transfer from the metal center to the C-C bond of the unsaturated hydrocarbons, resulting in the formation of two new basins located on the carbon atoms (away from hydrogen atoms) and the reduction of the number of attractors of the C-C basin. The interaction between Mo(1,2) and C(2)H(4) (or C(2)H(2)) should be considered as a chemical reaction, which causes the multiplicity change. Contrarily, there is no charge transfer between Mo(1,2) and NH(3), and the partners are bound by an electrostatic interaction. 相似文献
140.
Three new hetero‐bischelated rhodium (III) complexes of cis‐[Rh(PA)(L)Cl2]Cl (where PA = phenylpyridin‐2‐ylmethylene‐amine; L = 2,2′‐bipyridine, 2,2′‐dipyridylamine and 1,10‐phenanthroline) have been successfully prepared and characterized. Each complex shows high intensity bands in the UV region, and these are assigned to spin‐allowed π‐π* transitions. The medium‐intensity absorption band profile in the lower energy region can be explained by convolution of spin‐allowed CT and d‐d* transitions. The emission spectra at low temperature (77 K) of these complexes in EtOH/MeOH (4:1 v/v) are virtually identical. They all exhibit a broad, symmetric, and structureless red emission with a microsecond lifetime and hence are assigned as the d‐d* phosphorescence. 相似文献