Publication


Featured researches published by Heinz Riffel.


Zeitschrift für Naturforschung B | 1988

Element–Element-Bindungen, IV. Molekül-und Kristallstruktur des Tetramethyldiphosphans und -diarsans /Element–Element Bonds, IV. Molecular and Crystal Structure of Tetramethyldiphosphane and -diarsane

Otto Mundt; Heinz Riffel; Gerd Becker; Arndt Simon

Abstract The molecular and crystal structures of the isotypic compounds tetramethyldiphosphane 1 and -diarsane 2 have been determined by single crystal X-ray diffraction (monoclinic; C2/m; Z = 2; 1/2: -155/-144 °C\a = 540.6(2)/555.8(2); b = 1131.0(6)/l 136.7(6); c -602.5(2)/612.8(2) pm;β = 97.31(3)/95.24(3)°;P-P 221.2(1)/As-As 242.9(1) pm). In accordance with the crystallographically imposed symmetry 2/m, the molecules adopt antiperiplanar conformation. Their crystal structures are closely related to those of the homologues tetramethyldistibane 3 [1] and -dibismuthane 4 [3]. As found for the latter compounds, the E -E units (E = P, As) are also aligned in linear chains, but the intermolecular E···E contacts (P···P 381/As···As 370 pm) do not allow any extended interaction between molecules, which otherwise would result in thermochromic effects.


Zeitschrift für Naturforschung B | 1985

1.1.3.3-Tetrakis(dimethylamino)-1λ5,3λ5-diphosphet / 1.1.3.3-Tetrakis(dimethylamino)-1λ5,3λ5-diphosphete

Jürgen Svara; Ekkehard Fluck; Heinz Riffel

The title compound 1 was prepared by reacting methyl-bis(dimethylamino)difluorophosphorane with butyllithium at -95 °C. The crystalline product is characterized by its NMR and IR spectra. The results of the X-ray crystal and molecular structure analyses are reported.


Zeitschrift für Naturforschung B | 1984

Element—Element-Bindungen, III [1]. Intermolekulare Sb···Sb-Wechselwirkungen im kristallinen Tetramethyldistiban1 / Element—Element Bonds, III [1]. Intermolecular Sb···Sb Interactions in Crystalline Tetramethyldistibane

Otto Mundt; Heinz Riffel; Gerd Becker; Arndt Simon

Tetramethyldistibane which shows a colour change from deep red to pale yellow upon melting, has been subjected to single-crystal x-ray diffraction analyses at -21° and -139 °C (orthorhombic,Pnma, Z = 4, -139 °C: a = 1150.9(3); b = 1136.8(2) ; c = 651.6(2) pm). The molecules adoptthe antiperiplanar conformation with the crystallographically imposed symmetry m (Cs) and arealigned in extended linear antimony chains with short intermolecular contacts (-139 °C: Sb-Sb283.8(1), Sb···Sb 367.8(1) pm; Sb-Sb---Sb 179.2°). The structure is compared with those ofsimilar compounds.


Phosphorus Sulfur and Silicon and The Related Elements | 1987

DIE REAKTION VON 1,1,3,3-TETRAKIS(DIMETHYLAMINO)-1Λ5,3Λ5-DIPHOSPHET MIT ACETONITRIL

Ekkehard Fluck; Bernhard Neumüller; Gernot Heckmann; Heinz Riffel

Abstract Reaction of 1,1,3,3-tetrakis(dimethylamino)-1Λ5,3Λ5-diphosphete 1 with acetonitrile yields 3,3,5,5-tetrakis(dimethylamino)-3,5-diphospha-hexa-2,4-dienenitrile, 2. Properties, NMR spectra and the results of an X-ray structural analysis are reported. Die Umsetzung von 1,1,3,3-Tetrakis(dimethylamino)-1Λ5,3Λ5-diphosphet 1 mit Acetonitril liefert 3,3,5,5-Tetrakis(dimethyl-amino)-3,5-diphospha-hexa-2,4-diennitril, 2. Eigenschaften, NMR-Spektren und die Ergebnisse einer Rontgenstrukturanalyse werden mitgeteilt.


Zeitschrift für Naturforschung B | 1987

Ein Derivat des 1λ5,3λ5,5λ3-Triphosphabenzols / A Derivative of 1λ5,3λ5,5λ3-Triphosphabenzene

Ekkehard Fluck; Gerd Becker; Bernhard Neumüller; Robert Kneb; Gemot Heckman; Heinz Riffel

Abstract The title compound was prepared by reacting 1,1,3,3-tetrakis(dimethylamino)-1λ5,3λ5-diphosphete with 2,2-dimethylpropylidynephosphane and characterized by NMR spectra and X-ray structure analysis.


Journal of Organometallic Chemistry | 1987

Die kristallstruktur von dimethylamin-trimethylboran

Konstantinos Ouzounis; Heinz Riffel; H. Hess

Abstract The crystal structure of the addition compound dimethylamine trimethylborane was determined by X-ray diffraction studies. The boronnitrogen bond distance of 165.6 pm is the longest observed in this class of compounds.


Phosphorus Sulfur and Silicon and The Related Elements | 1982

ÜBER DIAZADIPHOSPHETIDINE. V1 SYNTHESE UND STRUKTUR VON 1.3.2.4-DIAZA-Λ5,Λ3-UND Λ5,Λ5-DIPHOSPHETIDINEN

Ekkehard Fluck; Horst Richter; Heinz Riffel; H. Hess

Abstract Syntheses, properties, nmr spectra, and structures of trans-1.3-bis(diethoxyphosphoryl)-2.4-bis(diethylamino)-2-oxo-1.3.2.4-diaza-Λ5,Λ3-diphosphetidine (2), trans-1.3-bis(diethoxyphosphoryl)-2.4-bis(diethylamino)-2-thio-1.3.2.4-diaza-Λ5,Λ3-diphosphetidine (3) and trans-1.3-bis(diethoxyphosphoryl)-2.4-bis(diethylamino)-2.4-dithio-1.3.2.4-diaza-Λ5,Λ5-diphosphetidine (4) are reported. Synthesen, Eigenschaften, NMR-Spektren und Strukturen der Verbindungen trans-1.3-Bis(diethoxyphosphoryl)-2.4-bis(diethylamino)-2-oxo-1.3.2.4-diaza-Λ5,Λ3-diphosphetidin (2), trans-1.3-Bis(diethoxyphosphoryl)-2.4-bis(diethylamino)-2-thio-1.3.2.4-diaza-Λ5,Λ3-diphosphetidin (3) und trans-1.3-Bis(diethoxyphosphoryl)-2.4-bis(diethylamino)-2.4-dithio-1.3.2.4-diaza-Λ5,Λ5-diphosphetidin (4) werden mitgeteilt.


Phosphorus Sulfur and Silicon and The Related Elements | 1988

AZADIPHOSPHAFULVENE, EINE NEUE VERBINDUNGSKLASSE

Ekkehard Fluck; Bernhard Neumüller; Gernot Heckmann; Heinz Riffel

Abstract Synthesis, properties, NMR, IR, and mass spectra as well as the results of an X-ray structural analysis of 1,1,3,3-tetrakis(dimethylamino)-1λ5, 3λ5-[1,3] diphosphol-4-on-phenylimine, 2, are described. Synthese, Eigenschaften, NMR-, IR- und Massenspektren sowie die Ergebnisse einer Rontgenstrukturanalyse von 1,1,3,3-Tetrakis(dimethylamino)-1λ5, 3λ5-[1,3] diphosphol-4-on-phenylimin, 2, werden beschrieben.


Phosphorus Sulfur and Silicon and The Related Elements | 1987

From 1,3-Diphosphacyclobutadiene to 1,3,5-triphosphabenzene

Ekkehard Fluck; Bernhard Neumüller; Gernot Heckmann; Roland Braun; Gerd Becker; Robert Knebl; Heinz Riffel

Abstract Alkyl- and aryldiaminodifluorophosphoranes 1 can easily be obtained by fluorination of alkyl- and aryldiaminophosphanes with sulfur tetrafluoride, SF4 1. Peralkylated alkyldiaminodifluorophosphoranes react with one mole of n-butyllithium to form P-fluoro-ylides, a class of compounds which had not been described previously 2 . Methylbis(dimethylamino)difluorophosphorane 2, e.g., reacts with butyllithium to give methylenebis(dimethylamino)fluorophosphorane 3, a colorless liquid, b.p. 42 °C (10 Torr)2: For P-chloro-ylides such as (t-C4H9)2PCI=CHSi(CH3)3, the chloro ligand is substituted by the alkyl group upon reaction with methyl-or n-butyllithium 3,4; however, P-fluoro-ylides behave in a different way. If 2 is reacted with two moles of butyllithium, the main product is the crystalline, colorless 1,1,3,3-tetrakis(dimethylamino)-1Δ5, 3Δ5−diphosphete or 1,1,3,3-tetrakis(dimethylamino)-1Δ5, 3Δ5−diphosphacyclobutadiene 4 (chemical shift δ (P) = 48.9 ppm)5.


TMPM Tschermaks Mineralogische und Petrographische Mitteilungen | 1980

Die Kristallstruktur von Warikahnit, Zn3[(H2O)2|(AsO4)2]

Heinz Riffel; Paul Keller; H. Hess

Die Kristallstruktur des neuen Minerals Warikahnit, Zn3[(H2O)2|(AsO4)2], wurde mit Diffraktometerdaten bestimmt und bis zuR=0,038 fur 3428 unabhangige Reflexe verfeinert.

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