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1.
Preparation and Molecular Structures of Oligofunctional Dirhenium Carbonyl Derivatives from Dirhenium Nonacarbonylphosphane Starting with dirheniumdecacarbonyl, one CO-Ligand was eliminated oxidatively and substituted by the labile acetonitrile ligand. As an intermediate eq-Re2(CO)9NCCH3 was received. The reaction of this labilised carbonyl with tris(trimethylsilyl)phosphine and subsequent methanolysis gave ax-Re2(CO)9PH3, which was isolated and characterized for the first time. Photochemical and thermal reaction of ax-Re2(CO)9PH3 led to the new bi- and trinuclear complexes Re2(μ-H)(μ3-PHRe(CO)5)(CO)8, Re2(μ-PH2)2(CO)8 and Re2(μ-H) · (μ-PH2)(CO)8, which were characterized by IR-, 1H- and 31P-NMR spectroscopy. The structures of ax-Re2(CO)9PH3, Re2(μ-H)(μ3-PHRe(CO)5)(CO)8 and Re2(μ-PH2)2(CO)8 were confirmed by single-crystal X-ray analysis. ax-Re2(CO)9PH3 has a very short Re? P bond length of 228(2) pm. 相似文献
2.
N. M. Agababyan I. V. Ajinenko Yu. A. Belokopytov K. S. Belous H. Boettcher F. Botterweck M. M. Chapkin P. V. Chliapnikov F. Crijns A. De Roeck E. A. De Wolf K. Dziunikowska A. M. F. Endler A. Eskreys Z. C. Garutchava P. van Hal T. Haupt A. I. Katargin W. Kittel S. S. Megrabyan F. Meijers A. B. Micha?owska V. I. Nikolaenko K. Olkiewicz V. M. Ronjin R. Rosmalen H. M. T. Saarikko L. Scholten E. K. Shabalina J. Stepaniak O. G. Tchikilev V. A. Uvarov F. Verbeure R. Wischnewski S. A. Zotkin Y. V. Yarba EHS-NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1990,46(3):387-395
We report on a study of ρ0, ρ+, ω, \(\bar K^{*0} (892)\) andK *0 (892) inclusive production in π+ p interactions at 250 GeV/c, for ρ+, \(\bar K^{*0} (892)\) for the first time in a π+ p experiment. The data are compared withK + p data in the same experiment, with results of other experiments and with quark-parton models. Interesting differences are found between ρ+,0 and ω production. 相似文献
3.
The multiplicity distribution of all charged particles, as well as that of negatives and positives taken separately have been fitted by a number of recently proposed parametrizations. The negative binomial (2 parameters) and Laguerre distribution (3 parameters), in general, give good and very similar fits, but one of the parameters of the Laguerre distribution remains undetermined by the fit. The Krasznovszky-Wagner distribution (3 parameters) is better than the two first ones for full phase space, but slightly worse in intermediate rapidity intervals. Its disadvantage is the behaviour atn=0. The Branching distribution does not fit at an energy of \(\sqrt s = 22\) GeV. 相似文献
4.
V. V. Aivazyan I. V. Ajinenko Yu. A. Belokopytov P. C. Bosetti H. B?ttcher F. Botterweck P. V. Chliapnikov F. Crijns A. De Roeck E. A. De Wolf Th. Driever K. Dziunikowska A. Eskreys W. Friebel Z. C. Garutchava V. G. Gavrjusev H. Graessler P. van Hal T. Haupt W. Kittel S. S. Megrabyan F. Meijers A. B. Micha?owska V. I. Nikolaenko L. C. S. Oliveira K. Olkiewicz L. P. Petrovikh E. Riipinen V. M. Ronjin A. M. Rybin H. M. T. Saarikko W. Schmitz L. Scholten R. Schulte O. G. Tchikilev L. A. Tikhonova A. G. Tomaradze V. A. Uvarov F. Verbeure R. Wischnewski A. Wróblewski S. A. Zotkin NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,42(4):533-542
Forward-backward multiplicity correlations in σ+,K + p andpp collisions at 250 GeV/c ( \(\sqrt s \) =22 GeV) are given for all charges and for the different charge combinations. The correlations are found to be caused predominantly by centrally produced particles. It is demonstrated that this result is an agreement with observations at the ISR and the CERNp \(\bar p\) -Collider. The results are compared to expectations from LUND, DPM and FRITIOF Monte Carlo models and a geometrical picture relating correlations in hadron-hadron collisions toe + e ? data in terms of impact parameters is tested. 相似文献
5.
Zusammenfassung Seit der Entdeckung des 4-Scheitel-Satzes durch S. Mukhopadhaya (1909) und A. Kneser (1912) hat sich eine umfangreiche Literatur über Scheitel- und verwandte Sätze entwickelt. Unter anderem wurden ebene Bogen auf Scheitel hin untersucht bzgl. Charakteristiken, welche von k 1 Parametern stetig abhängen. Wir legen für die wichtigsten Sätze aus diesem Teil der Theorie überarbeitete Definitionen und Beweise unter vereinfachten Voraussetzungen vor.
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6.
S. Banerjee S. N. Ganguli A. Gurtu R. Raghavan A. Subramanian Y. Goldschmidt-Clermont R. T. Ross S. Squarcia K. Dziunikowska T. Haupt P. Girtler D. Kuhn K. W. J. Barnham J. Wells P. R. S. Wright J. Macnaughton F. Mandl F. Shabaan M. Bardadin-Otwinowska M. Szczekowski 《Zeitschrift fur Physik C Particles and Fields》1986,31(3):401-408
Results on inclusive ? production inK ? p interactions at 110 GeV/c are presented. The production cross section is found to be larger than in πp andpp interactions at similar energies, suggesting OZI allowed \(s\bar s\) fusion to be the dominant mechanism in ? production. Thex distributions of ? and \(\bar K^{*0} \) are found to be similar to each other over the entirex range suggesting an overall strangeness suppression factor of 0.20±0.04 in the sea to be the dominant source of the difference in the cross section for ? and \(\bar K^{*0} \) . There is no evidence of a narrowφπ ? state around 2.1 GeV/c2 as suggested byK + experiments, but there is some excess of events in the region 1.94?1.98 GeV/c2 consistent with theF-meson mass as observed ine + e ? experiments. 相似文献
7.
Non-covalently molecularly imprinted polymers (MIPs) for beta2-amino acids were prepared for the first time. N-(2-chlorobenzyloxycarbonyl)-(R)-beta2-homophenylalanine (N-2-ClZ-(R)-beta2-HPhe) was imprinted with methacrylic acid (MAA) and/or 4-vinylpyridine (4-VPy) as the functional monomers, with ethylene glycol dimethacrylate (EDMA) as the cross-linker. The MIPs made with different ratios of MAA:4-VPy were studied in HPLC mode. The results show that MIPs made with 4-VPy yielded the best chiral separation factor (alpha= 1.86) for the template molecule. The importance for an efficient separation of pi-stacking interactions between the MIPs and the template molecule is demonstrated. Racemates of Z-alpha-amino acids and beta-amino acid analogues of the template were either not or poorly resolved by the MIPs, thus demonstrating the close three-dimensional complementarity of the MIPs' recognition sites with the template. 相似文献
8.
Preparation of Acetatolead(1V) and Acetatotin(1V) Manganese Pentacarbonyls by Acidolysis of (C6H5)4?n M[Mn(CO)5]n (M ? Sn, Pb; n = 1, 2) with Acetic Acid By acidolysis of (C6H5)4?nM[Mn(CO)5]n (M ? Sn, Pb; n = 1, 2) with acetic acid no M? Mn bonds are broken, but M? C bonds. In this reaction (CH3COO)2M[Mn(CO)5]2 is formed from (C6H5)2M[Mn(CO)5]2, and (CH3COO)3SnMn(CO)5 and (CH3COO)2C6H5PbMn(CO)5 from (C6H5)3MMn-(CO)5. (CH3COO)2C6H5SnMn(CO)5 is prepared from Cl2C6H5SnMn(CO)5 and AgCH3COO. According to IR spectroscopic data the acetato ligands of the diacetato complexes are bidentate, while in (CH3COO)3SnMn(CO)5 bi- and monodentate carboxylate groups are present. For the central atoms Sn and Pb octahedral coordination is proposed. 相似文献
9.
Heterobimetallic Complexes with Chelate Ligands from Multidentate Amines and 1,1-Bis(diphenylphosphine)ethene By an addition reaction of bidentate amines Me2N(CH2)nNH2 (n = 2, as-4C2N; 3, as-5C2N) and vinylidene derivatives with an activated double bond CH2 = C(PPh2)2M(CO)4 (M = Cr, Mo, W) were synthesized in dichlormethane unsymmetrical chelate ligands of the type as-4C2N (or as-5C2N)PPM(CO)4. They gave with divalent salts M′Y2 (Y = ac, M′ = Cu, Ni. Y = Cl, M′ = Zn, Cd, Hg) the coloured bimetallic complexes M′Y(as-4C2N) (or as-5C2N)PPM(CO)4 which were characterized by means of IR-, UV/VIS spectroscopic and 1H, 13C and 31P NMR measurements. The molecular structures of the complexes Cuac2(as-5C2N)PPCr(CO)4, I and that of CdCl2(as-4C2N)PPCr(CO)4, II , were acertained by results of single crystal X-ray determinations. In the crystals of I—II , the coordination polyhedron of each chromium(0) central atom containing two phosphorous donor atoms in a four-membered chelate ring and four terminal CO ligands is octahedrally distorted. This coordination sphere is connected at the carbon ring atom via a methylen chain group (spacer) with the bidentate amine ligand, which has a secondary and a tertiary nitrogen donor atom. Both nitrogen atoms are coordinated with the Cuac2 under formation of a new kind of [4 + 2]-coordination in a trischelate complex. The six-membered diamine chelat ring in I has a chair-like conformation. The chromium-cadmium complex II is dimer from which the Cd central atoms obtain the rare coordination number of five. The related five-membered diamine chelate ring has δ conformation. 相似文献
10.
Gallium-, Indium-Manganese-, and Thallium-Rhenium Carbonyl Compounds Compounds of type Na{Cl4?nM[Mn(CO)5]n} (M ? Ga, In; n = 1, 2, 3) were prepared by reaction of the Lewis acids MCl3 and NaMn(CO)5. Instead of the sodium salts were obtained the compounds (C3H7CO2)2InMn(CO)4L (Indium atom with the coordination number 5) from Indium(III) butyrate with two carboxylate groups bonded as chelate ligands and NaMn(CO)4L [L ? CO, P(C6H5)3] in the molar ratio 1:1. By reacting TlCl with NaRe(CO)5 i.r. spectroscopic measurements of the solution pointed out the intermediate product TlRe(CO)5, which was unstable against a disproportionation reaction into Tl and Tl[Re(CO)5]3. The last named compound delivered as a thermal decomposition product Re2(CO)8[μ-TlRe(CO)5]2. I.r. bands of the new compounds were assigned. 相似文献