Rolf Appel
University of Bonn
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Featured researches published by Rolf Appel.
Journal of Organometallic Chemistry | 1976
Rolf Appel; Klaus Geisler
Abstract Organosilylphosphines can easily be synthesized by cleavage of diarylphosphines with lithium and further reaction with chlorotimethylsilane. Additionally three other possibilities for the synthesis of phenylbis(trimethylsilyl)phosphine are described.
Tetrahedron Letters | 1986
Rolf Appel; Peter Fölling; Winfried Schuhn; Falk Knoch
Abstract The first stable acyclic 1,3-diphosphabutadiene was prepared by reaction of phosphaalkene 2 with 2,4,6-tri-tert-butylphenylphosphaketene 1 .
Tetrahedron Letters | 1980
Rolf Appel; Benno Laubach
Abstract Interaction of different halogenated isocyanide dichlorides with phenylbis(trimethylsilyl)phosphine either yields 1,3,4,6-tetraphosphahexadienes-(1,5) via the (phosphinomethylene)phosphines or 1,3-diphosphetanes by way of the “monophosphacarbodiimides”.
Journal of Organometallic Chemistry | 1987
Rolf Appel; W. Schuhn; Falk Knoch
Abstract (R = 2,4,6-tri-t-butylphenyl) and (R = 2,4,6-tri-t-butylphenyl) are two new nickel complexes with a 1,3-diphosphaallyl ligand. Both structures have been determined by X-ray analysis.
Journal of Organometallic Chemistry | 1986
Rolf Appel; F. Knoch; V. Winkhaus
Abstract η 1 -[9CO 3 Ni(RPCCPh 2 )] (R = 2,4,6-tri-t-butylphenyl), the first complex of a 1-phosphaallene has been isolated and the structure has been determined by X-ray analysis.
Journal of Organometallic Chemistry | 1988
Rolf Appel; B. Niemann; W. Schuhn; N. Siabalis
Abstract Treatment of the 1,3-diphospha(1,3)butadiene (I) with Ni(CO)4 or Fe2(CO)9 affords η1- or η4-coordination to a M(CO)3 fragment. Complex formation by the reaction of 1,4-diphospha(1,3)butadiene (IV) with C7H8M(CO)4 orM(CO)5THF (M = Cr, Mo, W) yields the doubly η1-coordinated compounds, which readily undergo E/Z-isomerization compared to IV. Bonding of a Mo(CO)4 fragment to the 1,2,4-triphospha(1,3)butadiene (VIII) was attained by two different reactions.
Journal of Molecular Structure | 1978
Angelika Turowsli; Rolf Appel; Wolfgang Sawodny; Karl Molt
Abstract The IR and Raman spectra of solid and dissolved S 4 N 4 , S 4 N 4 H 4 , S 4 N 4 D 4 and S 3 N 3 Cl 3 have been recorded and are assigned according to D 2d , C 4v and C 3v symmetry respectively. In the solid state, many forbidden bands and splittings of degenerate vibrations are observed because of the symmetry lowering in the crystals. Due to the different size and shape of the rings and to strong coupling of the normal modes there is no clear correlation between the SN ring stretching vibrations and the strength of the SN bonds, except for the one of the E modes. However, the stretching force constant show the trend expected from changes in interatomic distances.
Journal of Organometallic Chemistry | 1975
Rolf Appel; Mechthild Halstenberg
Zusammenfassung In Fortfuhrung unserer Versuche, viergliedrige Phosphor-StickstoffHeterocyclen durch Reaktion yon Aminoiminophosphinen (I) [1,2] mit geeigneten Imiddonoren wir Iminophosphoranen [3] oder Iminosulfuranen [4] zu synthetisieren, haben wit jetzt auch Bis(trimethylsilyl)schwefeldiimid mit I umgesetzt. Wir fanden, dass die Reaktion erwartungsgemass unter Imid-Ubertragung verlauft, die Natur der gebildeten Reaktionsprodukte abet stark von dem angewandten Molverhaltnis abhangt. Uberraschenderweise wurde mit einem Unterschuss an Schwefeldiimid eine Substanz isoliert, die keinen Schwefel enthielt und bei der es sich nach der Elementaranalyse um ein Addukt aus I und dem daraus dutch Imid-Ubertragung entstandenen Bis(trimethylsilyl)amino-bis(trimethylsilylimino)phosphoran (II) handelt. Besonders einfach und ohne Nebenprodukte lasst sich III dementsprechend aus I und II nach Gl. 1 darstellen. Aufgrund von Molmassebestimmungen, NMR- und Massenspektren nehmen wit an, dass dieser Verbindung die Struktur eines 2,4-Bis(trimethylsilyl)-l,3-bis[bis(trimethylsilyl)amino]-1-trimethylsilylimido-2,4,1 η 5 , 3η 3 - diazadiphosphetidins (III) zukommt.
Phosphorus Sulfur and Silicon and The Related Elements | 1990
Rolf Appel
Abstract The synthesis of various mono-, di- and mphosphabutadienes, of two hiphosphapentadienes and of several mono-, di- and tetraphospha-hexadienes is being reported. Their chemistry demonstrates an astonishing relationship to the corresponding olefinic compounds.
Phosphorus Sulfur and Silicon and The Related Elements | 1988
Rolf Appel; Peter Schulte; Falk Knoch
Abstract Synthesis and properties of up to now unknown P,P,P′,P′-Tetrakis(methylene)-[sgrave]3μ5-bisphosphoranes are reported.