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Friedrich-Wilhelm Bauer 《Mathematische Annalen》1963,149(2):105-130
Ohne Zusammenfassung 相似文献
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Aboul-fetouh E. Mourad Friedrich-Wilhelm Raulfs Henning Hopf 《Monatshefte für Chemie / Chemical Monthly》1985,116(6-7):701-709
The charge-transfer (CT) spectra of the -complexes formed by a number of -acceptors with several indenophanes as well as indene as a model compound have been measured in methylene chloride at 20 °C. Association constants and transition energies of these complexes as well as ionization potentials of the -donors have been determined. The data obtained indicate the existence of transannular electronic interactions in the indenophane nucleus. Furthermore, the pseudo-para- andmeta[2.2]indenophane isomers (3 and4) show a large difference in their -base strength. A good linear relationship has been observed between the association constants and max of the long wavelength CT bands for the -complexes of these -donors with both tetracyanoethylene (TCNE) and 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). All CT complexes studied have a 1:1 stoichiometry.
Charge-transfer-Komplexe aus Indenophanen und -Akzeptoren
Zusammenfassung Die Charge-transfer-Spektren (CT-Spektren) von -Komplexen aus Indenophanen bzw. der Modellverbindung Inden und verschiedenen -Akzeptoren wurden in Methylenchlorid bei 20 °C bestimmt. Die Assoziationskonstanten und Übergangsenergien dieser Komplexe sowie die Ionisationspotentiale der -Donatoren wurden ermittelt. Die Daten sprechen für das Vorliegen transannularer elektronischer Wechselwirkungen im Indenophan-System. Die isomeren pseudo-para- und -meta[2.2]indenophane3 und4 unterscheiden sich in ihrer -Basizität deutlich. Es besteht eine gute lineare Korrelation zwischen den Assoziationskonstanten und max der langwelligen CT-Banden der verschiedenen -Donatoren mit Tetracyanoethylen (TCNE) und 2,3-Dichlor-5,6-dicyano-p-benzochinon (DDQ). Alle untersuchten CT-Komplexe besitzen 1:1-Stöchiometrie.相似文献
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J.Richard Blackborow Udo Feldhoff Friedrich-Wilhelm Grevels Robert H. Grubbs Akira Miyashita 《Journal of organometallic chemistry》1979,173(2):253-261
The catalytic cyclodimerization of norbornadiene by reaction with nickel atoms has been re-investigated. Nickela-cyclopentane derivatives are formed in the presence of α,α′-dipyridyl, α,α′-dipyridyl-exo-trans-endo-3-nickela-pentacyclo[9.2.1.15,8 02,10.04,9]-pentadeca-6,12-diene being the major component. By contrast, the catalytic dimerization leads predominantly to the exo-trans-exo isomer of pentacyclo[8.2.1.14,7.02,9.03,8] tetradeca-5,11-diene. A norbornadiene cyclotrimer of exo-trans-exo-trans-exo structure is subsequently formed. 相似文献
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Lyon EJ Shima S Boecher R Thauer RK Grevels FW Bill E Roseboom W Albracht SP 《Journal of the American Chemical Society》2004,126(43):14239-14248
The iron-sulfur-cluster-free hydrogenase Hmd (H(2)-forming methylenetetrahydromethanopterin dehydrogenase) from methanogenic archaea has recently been found to contain one iron associated tightly with an extractable cofactor of yet unknown structure. We report here that Hmd contains intrinsic CO bound to the Fe. Chemical analysis of Hmd revealed the presence of 2.4 +/- 0.2 mol of CO/mol of iron. Fourier transform infrared spectra of the native enzyme showed two bands of almost equal intensity at 2011 and 1944 cm(-)(1), interpreted as the stretching frequencies of two CO molecules bound to the same iron in an angle of 90 degrees . We also report on the effect of extrinsic (12)CO, (13)CO, (12)CN(-), and (13)CN(-) on the IR spectrum of Hmd. 相似文献
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