Darstellung, Strukturen und Eigenschaften von Tris‐hexamethyl‐trisila‐tetraphospha‐nortricyclen‐bis‐chromtricarbonyl [P₄(Sime₂)₃]₃[Cr(CO)₃]₂

Abstract

Hexamethyl‐trisila‐tetraphospha‐nortricyclen P4(Sime2)3 1 reagiert mit C6H6Cr(CO)3 bzw. (CHT)Cr(CO)3 (CHT  Cycloheptatrien) unter Bildung von [P4(Sime2)3]3[Cr(CO)3]2 3 (rote Kristalle), in dem jedes der Cr‐Atome mit einem P‐Atom eines P‐Dreiringes der drei Moleküle von 1 verbunden ist. 3 bildet sich auch beim Erwärmen einer Lösung von P4(Sime2)3Cr(CO)5 in Benzol oder THF auf 120°–130°C. Die Verbindung 3 kristallisiert in einer orthorhombischen und einer durch ein Mol Toluol stabilisierten hexagonalen Form. Nach Einkristalluntersuchungen sind die Symmetrie ¯6, Abstände und Winkel in beiden Formen nahezu unverändert. Die o‐Form entspricht einer kubisch dichten, die h‐Form einer hexagonal dichten Molekülpackung.

Silylphosphanes: Developments in Phosphorus Chemistry

“…Other examples are the reactions of PtBu 3 with tBuX (X ) halogen), yielding tBu 3 PH + X -193 as well as the formation of tBu 2 SiHCl and isobutene from tBuSiCl 3 and tBuLi. 194 Similarly 268 with tBuCl at -70 °C exclusively yields (tBu 2 P) 2 PH according to (161).…”

“…According to an X-ray investigation, complex 424 has the structure shown in Figure 28 and can be characterized as an octahetero[2.2.2]barrelane, the 3-fold axis of which goes through the both chromium atoms. 161 P 7 (SiMe 3 ) 3 (367) reacts with Cr(CO) 5 ‚THF, furnishing various chromium carbonyl complexes in which the Cr(CO) 5 fragment is bonded to an equatorial phosphorus atom (P e ) and only with increasing coordination also to a basal P atom (P b ). 162 A comprehensive report about the reactions of heptaphosphanes P 7 R 3 (R ) Et, iPr, SiMe 3 ) with transition metal complexes was given by Baudler and Glinka.…”

“… Another possible synthesis for 424 is by heating P 4 (SiMe 2 ) 3 Cr(CO) 5 ( 420 ) in benzene or THF (120 °C, sealed tube) for several hours. According to an X-ray investigation, complex 424 has the structure shown in Figure and can be characterized as an octahetero[2.2.2]barrelane, the 3-fold axis of which goes through the both chromium atoms 28 Molecular structure of [P 4 (SiMe 2 ) 3 ] 3 [Cr(CO) 3 ] 2 ( 424 ).…”

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28 Molecular structure of [P 4 (SiMe 2 ) 3 ] 3 [Cr(CO) 3 ] 2 ( 424 ). Reprinted with permission from ref . Copyright 1982 Wiley-VCH Verlag GmbH.

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Bicyclic dinuclear tris-(ditopic diphosphane) complexes of zerovalent group 10 metals

“…19,21,22 There is also a report of P-P triple bridges with [P 4 (SiMe 2 ) 3 ] ligands between two Cr(CO) 3 units where the dihedral angle is 0 . 23 Multimetallic platforms have received a surge in interest due to their increased catalytic potential resulting from the interactions between metallic centers. 24 Such complexes containing multiple bridging ligands are conferred increased stability against dissociation into monomeric units.…”