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Zusammenfassung Die optisch aktiven Methylcymantren-- und--carbonsäuren bekannter Absolutkonfiguration wurden auf dem Weg: COClCON3NH2Hal in die entsprechenden Chlor-, Brom- und Jod-methylcymantrene umgewandelt, und dieORD der genannten Verbindungen sowie die Drehungen der Methylcymantrenylisocyanate (dargestellt aus den Aziden) gemessen. In den Halogen-methylcymantrenen liegen optisch aktive Metallocene vor, bei denen der Beitrag zur Drehung nur aus der Atomchiralität stammen kann, während bei den anderen Methylcymantrenderivaten auch die Konformationschiralität einen Beitrag leistet. Entsprechend sind die [M]D-Werte der Halogen-methylcymantrene proportional den Polarisierbarkeiten von Hal. DieNMR-Daten der neuen Cymantrenderivate werden mitgeteilt und kurz diskutiert.
Mit 3 Abbildungen
16. Mitt.:H. Falk undK. Schlögl, Mh. Chem.99, 578 (1968).
a) 3. Mitt.:Heike Gowal undK. Schlögl, Mh. Chem.99, 267 (1968); b) 2. Mitt.:Heike Gowal undK. Schlögl, Mh. Chem.98, 2302 (1967); c) 1. Mitt.:S. G. Cottis, H. Falk undK. Schlögl, Tetrahedron Letters [London]1965, 2857. 相似文献
The optically active methylcymantrene-- and--carboxylic acids of known absolute configuration were converted into the corresponding chloro, bromo and iodo methylcymantrenesvia their chlorides, azides and amines. TheORD of these cymantrene derivatives as well as the rotations of methylcymantrenyl isocyanates (prepared from the azides) are reported. The halogen methylcymantrenes represent optically active metallocenes, in which the contribution to the optical rotations originates only from atomic chirality, whilst in the case of the other methylcymantrene derivatives the conformational chirality also contributes. Correspondingly, the [M]D values of the halogen methylcymantrenes are proportional to the polarizibilities of Hal. TheNMR data of the new cymantrene derivatives are reported and briefly discussed.
Mit 3 Abbildungen
16. Mitt.:H. Falk undK. Schlögl, Mh. Chem.99, 578 (1968).
a) 3. Mitt.:Heike Gowal undK. Schlögl, Mh. Chem.99, 267 (1968); b) 2. Mitt.:Heike Gowal undK. Schlögl, Mh. Chem.98, 2302 (1967); c) 1. Mitt.:S. G. Cottis, H. Falk undK. Schlögl, Tetrahedron Letters [London]1965, 2857. 相似文献
14.
Syntheses, Structure Determination and Reactions of Phosphine Substituted Derivatives of Fe3(CO)9(μ3-CF)2 Photolysis of Fe3(CO)9(μ3-CF)2 1 in the presence of acetonitrile 2a or benzoenitrile 2b results in the substitution of a single carbonyl ligand by a nitrile ligand yielding Fe3(CO)8(CH3CN)(μ3-CF)2 3a and Fe3(CO)8(C6H5CN)(μ3-CF)2 3b, respectively. The acetonitrile ligand in 3a can be easily replaced by trimethyl-phosphine 4a or triphenylphosphine 4b . The monosubstituted compounds Fe3(CO)8(PR3)(μ3-CF)25, R = CH3 a, R = C6H5, b are obtained as major products besides a small amount of the disubsituted products Fe3(CO)7(PR3)2(μ3-CF)2 6. The structure of 5a has been elucidated by a single crystal X-ray structure determination. Thermal ligand substitution in 1, however, results in the formation of a mixture of mono-, disubstituted, and trisubstituted products, in which 6b is the major product for diphenylphosphine. 5a reacts with ethyne 7 forming a phosphine substituted diferra-allyl-cluster Fe3(CO)7(PR3)(μ3-CF)(μ3? CF? CH? CH) 8. The structure of one isomere of 8 has been determinated by X-ray crystallography. 相似文献
15.
Williams JR Smalley AL Sellinschegg H Daniels-Hafer C Harris J Johnson MB Johnson DC 《Journal of the American Chemical Society》2003,125(34):10335-10341
A series of samples ((AB)(x)(CD)(y))(z) were prepared containing both short repeat units (AB and CD) and long repeat units ((AB)(x)(CD)(y)), where the short repeat units were designed to have the composition appropriate to form square M(4)Sb(12) skutterudites (M = Fe, Co, or Ir; square = vacancy, La, or Y). X-ray diffraction and reflectivity were used to follow the evolution of the films from amorphous, layered materials to crystalline skutterudite superlattices as a function of annealing temperature and time. In all cases, the short repeat units interdiffused and crystallized the expected skutterudite, while the long repeat period persisted after annealing. The skutterudites crystallize with random crystallographic orientation with respect to the substrate. The observed splitting of the peaks in the high-angle diffraction data from the IrSb(3)/CoSb(3) sample indicates the formation of a novel superlattice structure with each grain having a random crystallographic orientation of the skutterudite lattice with respect to the superlattice direction. 相似文献
16.
In filaments of the moss Ceratodon purpureus , phototropism is controlled by the photoreceptor phytochrome. Thirty-three aphototropic mutants with a proposed defect in phytochrome-chromophore biosynthesis were isolated and analyzed. The phototropic response of those mutants was rescued with the precursor of the phytochrome chromophore, biliverdin. Phytochrome spectral activity was measured in 19 arbitrarily chosen mutants. All contained low but still measurable quantities of photoactive phytochrome; the highest level was around 15% of the wild-type. The level of total phytochrome (apophytochrome and holophytochrome) as assayed by immunoblotting was indistinguishable from wild-type. The content of photoactive phytochrome in Ceratodon is light-regulated. Phytochrome of wild-type kept for 24 h in red light was reduced to 50% as compared to dark controls but was unaffected by blue. The red-light-induced decrease was partially reversible by far-red light, indicating that phytochrome itself is the photoreceptor for this response. This regulation was further analyzed with the mutant ptr114 , which contains 15% photoactive phytochrome as compared to the wild-type. In this mutant, continuous red light given for 6 days decreased the level of spectrally active phytochrome down to 25% of dark controls, whereas the amount of phytochrome found on immunoblots was hardly reduced. This indicates that the loss of phytochrome affects only the holoprotein and implies that Ceratodon phytochrome is specifically degraded as a far-red-absorbing phytochrome. 相似文献
17.
Dietmar Rahner Stefan Machill Heike Schlörb Kerstin Siury Matthias Kloss Waldfried Plieth 《Journal of Solid State Electrochemistry》1998,2(2):78-84
An overview is given of intercalation materials for both the negative and the positive electrodes of lithium batteries, including
the results of our own research. As well as lithium metal as a negative electrode, we consider insertion materials based on
aluminium alloys. In the case of the positive electrode metal-oxides based on manganese, nickel and cobalt are discussed.
Received: 27 May 1997 / Accepted: 30 July 1997 相似文献
18.
Gupta P Das A Basuli F Castineiras A Sheldrick WS Mayer-Figge H Bhattacharya S 《Inorganic chemistry》2005,44(6):2081-2088
Reaction of chloranilic acid (H2ca) with [Os(bpy)2 Br2] (bpy = 2,2'-bipyridine) affords a dinuclear complex of type [{Os(bpy)2}2 (ca)]2+, isolated as the perchlorate salt. A similar reaction of H2ca with [Os(PPh3)2 (pap)Br2] (pap = 2-(phenylazo)pyridine) affords a dinuclear complex of type [{Os(PPh3)2 (pap)}2 (ca)]2+ (isolated as the perchlorate salt) and a mononuclear complex of type [Os(PPh3)2 (pap)(ca)]. Reaction of H2ca with [Os(PPh3)2(CO)2(HCOO)2] gives a dinuclear complex of type [{Os(PPh3)2(CO)2}2 (r-ca)], where r-ca is the two electron reduced form of the chloranilate ligand. The structures of the [{Os(PPh3)2 (pap)}2 (ca)](ClO4)2, [Os(PPh3)2 (pap)(ca)], and [{Os(PPh3)2(CO)2}2 (r-ca)] complexes have been determined by X-ray crystallography. In the [{Os(bpy)2}2 (ca)]2+ and [{Os(PPh3)2 (pap)}2 (ca)]2+ complexes, the chloranilate dianion is serving as a tetradentate bridging ligand. In the [Os(PPh3)2 (pap)(ca)] complex, the chloranilate dianion is serving as a bidentate chelating ligand. In the [{Os(PPh3)2(CO)2}2 (r-ca)] complex, the reduced form of the chloranilate ligand (r-ca(4-)) is serving as a tetradentate bridging ligand. All the four complexes are diamagnetic and show intense metal-to-ligand charge-transfer transitions in the visible region. The [Os(PPh3)2 (pap)(ca)] complex shows an Os(II)-Os(III) oxidation, followed by an Os(III)-Os(IV) oxidation on the positive side of a standard calomel electrode. The three dinuclear complexes show two successive oxidations on the positive side of SCE. The mixed-valent Os(II)-Os(III) species have been generated in the case of the two chloranilate-bridged complexes by coulometric oxidation of the homovalent Os(II)-Os(II) species. The mixed-valent Os(II)-Os(III) species show intense intervalence charge-transfer transitions in the near-IR region. 相似文献
19.
Bismuth Monoiodide, a Compound with Bi(O) and Bi(II) Bismuth monoiodide was synthesized in closed tubes from the elements as well as from Bi and HgI2 as a black coloured crystalline compound. With increasing temperature BiI passes two transitions. α-BiI is stable below 370 K and changes to β-BiI by a martensitic transition. γ-BiI is the stable modification above 564 K and decomposes at 585 K peritectically to BiI3 and a lower iodide. All three modification crystallize in the monoclinic space group C2/m. The structures (single crystal studies) of α-BiI and β-BiI are characterized by onedimensional infinite chains [Bi4I4] with covalent bonds but only weak interactions in between. The [Bi4I4]-chains are built up by two completely different Bi atoms. Bi(A) is only bonded to three Bi whereas Bi(B) has bonds to one Bi and four I. The average bond lengths are Bi? Bi = 304.5 pm and Bi? I = 313.7 pm respectively. The configuration of the Bi(A) atoms is typical for BiO and that one of the Bi(B) atoms is characteristic for Bi2+ with the electron configuration s2p1. Therefore, α-BiI and β-BiI are mixed valence compounds [BiOBi2+I4]. The structures are variants of the simple cubic polonium type of structure and differ in the stacking of connected units. The structures and their transitions, the possible configurations for monohalides BiX on principle as well as the energy balances of the disproportionation of Bi+ are discussed together in detail. 相似文献
20.
Michael Chariss Andrea Zickgraf Heike Stenger Elmar Bru Cristelle Desmarquet Martin Drger Silke Gerstmann Dainis Dakternieks James Hook 《Polyhedron》1998,17(25-26)
44 members of thecompound series Ph4−nMRn (M=Si, Ge, Sn, Pb; R=o-, m-, p-Tol; n=0–4) were synthesized (15 newcompounds). The crystal structures of Ph3Sn (o-Tol) and PhSn (o-Tol)3 were determined and compared to 16 known structures. Subject to the distanced (M–C), an interplay between through-space π–π repulsion and π–σ attraction leads to either elongated or compressed tetrahedral geometry. 29 Si-, 119 Sn- and 207 Pb-NMR chemical shifts were determined in solution and in the solid state. 73 Ge chemical shifts were measured only in solution. Anupfield or downfield sagging of the chemical shifts along each series is rationalized in terms of a π–σcharge transfer which is constrained by torsion of the aromatic groups. 相似文献