Formation of a Rhenium(VII) Phosphonio-Methylidyne Complex

The synthesis of tetrahedral complexes [Mo(NBut)2(CHPPh3)2], [W(NBut)2(CHPPh3)2] and [Re(NBut)3(CHPPh3)] having four π-donor ligands is reported; the X-ray structure of [W(NBut)2(CHPPh3)2] reveals strong π-interactions of both imido ligands [NBut] as well as (α-triphenylphosphonio)methylidene functions [CHPPh3+], with the d0 metal centre.

(α-Triphenylphosphonio)methylidene imido complexes of molybdenum, tungsten and rhenium: the first complexes exhibiting metal–ligand multiple-bonding with two carbon as well as two nitrogen centres

Die Kristallstrukturen der Titelverbindungen werden mit Hilfe von Rontgen-Einkristall-Strukturanalysen ermittelt. NH4[SbCl6] und NH4[WCl6] kristallisieren isotyp miteinander in der Raumgruppe C2/c mit vier Formeleinheiten pro Elementarzelle. Die NH4+-Ionen liegen auf einer zweizahligen Drehachse, die Metallatome der [MCl6]—-Ionen besetzen ein Inversionszentrum. Es bestehen schwache interionische Wasserstoffbruckenbindungen.



[K(18-Krone-6)(CH2Cl2)]2[WCl6]·6CH2Cl2 kristallisiert orthorhombisch in der Raumgruppe R3¯/m mit Z = 3. Die Verbindung bildet zentrosymmetrische Ionentripel, in denen die Kaliumionen mit je einer WCl3-Flache koordinieren. In trans-Position hierzu koordiniert das Cl-Atom eines CH2Cl2-Molekuls, so das zusammen mit den O-Atomen des Kronenethers Koordinationszahl 10 resultiert.



(PPh4)2[WCl6]·4CH3CN kristallisiert monoklin in der Raumgruppe P21/c mit Z = 4. Auch diese Verbindung bildet zentrosymmetrische Ionentripel, in denen zusatzlich die Acetonitrilmolekule uber schwache C—H···Cl-Kontakte mit dem [WCl6]2—-Ion verbunden sind.



Crystal Structures of the Hexachlorometalates NH4[SbCl6], NH4[WCl6], [K(18-crown-6)(CH2Cl2)]2[WCl6]·6CH2Cl2 and (PPh4)2[WCl6]·4CH3CN



The crystal structures of the title compounds were determined by single crystal X-ray methods. NH4[SbCl6] and NH4[WCl6] crystallize isotypically in the space group C2/c with four formula units per unit cell. The NH4+ ions occupy a twofold crystallographic axis, whereas the metal atoms of the [MCl6]— ions occupy a centre of inversion. There exist weak interionic hydrogen bridges.



[K(18-crown-6)(CH2Cl2)]2[WCl6]·6CH2Cl2 crystallizes in the orthorhombic space group R3¯/m with Z = 3. The compound forms centrosymmetric ion triples, in which the potassium ions are coordinated with a WCl3 face each. In trans-position to it the chlorine atom of a CH2Cl2 molecule is coordinated so that, together with the oxygen atoms of the crown ether, coordination number 10 is achieved.



(PPh4)2[WCl6]·4CH3CN crystallizes in the monoclinic space group P21/c with Z = 4. This compound, too, forms centrosymmetric ion triples, in which in addition the acetonitrile molecules are connected with the [WCl6]2— ion via weak C—H···Cl contacts.

Die Kristallstrukturen der Hexachlorometallate NH4[SbCl6], NH4[WCl6], [K(18‐Krone‐6)(CH2Cl2)]2[WCl6]·6CH2Cl2 und (PPh4)2[WCl6]·4CH3CN

Reactions of the Higher Halides of Niobium, Molybdenum and Tungsten with the Phosphorus-Ylide (Et2N)3P=CH2. X-Ray Structure of ((Et2N)3PCH2)2+ 2(WCl6)2-.

Abstract (Et2N)3 P=CH2 reacts with NbCl5 , WCl6 or WF6 under C-C bond formation to give the phosphonium cation [(Et2N)3 PCH2]2 2+ · [(Et2N)3PCH2]22+ [WCl6 ]2 - was isolated in a crystalline form and investigated by X-ray analysis. The reaction of (Et2N)3 P=CH2 with MOCl4 in a solvent proceeds with formation of the [(Et2N)3 PCH ]+ cation.

Reaktionen der höheren Halogenide des Niobs, Molybdäns und Wolframs mit dem Phosphor-Ylid (Et2N)3P=CH2 - Röntgenstruktur von [(Et2N)3PCH2]2 2+[WCl6]2-/ Reactions of the Higher Halides of Niobium, Molybdenum and Tungsten with the Phosphorus-Ylid (Et2N)3P=CH2– X-Ray Structure of [(Et2N)3PCH2]2 2+[WCl6]2-

Bernhard Mainz

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