Tris(triorganosilyl)methyl derivatives of potassium and lithium bearing dimethylamino or methoxy substituents at silicon. Crystal structures of KC(SiMe3)2(SiMe2NMe2), KC(SiMe2NMe2)3 and [LiC(SiMe3)(SiMe2OMe)2]2

The compounds HC(SiMe3)(SiMe2X)2, X = NMe2 or OMe, have been synthesized in several steps from the phenyl derivative HC(SiMe3)(SiMe2Ph)2 and metallated to give organometallic compounds of the type MC(SiMe3)(SiMe2X)2, M = K or Li. The structures of the compounds KC(SiMe3)2(SiMe2NMe2) and KC(SiMe2NMe2)3 consist of infinite chains in which cations are co-ordinated to both nitrogen and carbon centres, whereas the lithium compound [LiC(SiMe3)(SiMe2OMe)2]2 crystallises in a lattice of dimeric cage molecules. Structural trends in the series MC(SiMe3)n(SiMe2X)3-n, n = 0–3, M = K or Li, X = NMe2 or OMe, are discussed.

[1]  S. Liddle,et al.  Towards an understanding of the conjugate addition of organolithium reagents to α , β -unsaturated ketones: the isolation and solid-state structure of a monomeric lithium aluminate with very short agostic Li⋯HC interactions , 1999 .

[2]  S. Liddle,et al.  SYNTHESIS, CHARACTERISATION AND A THEORETICAL INVESTIGATION OF THE FORMATION OF LITHIUM DIALKYLALUMINIUM AMIDES , 1999 .

[3]  P. Hitchcock,et al.  Attachment of the New Bulky Ligand (Me3Si)2(Me2NMe2Si)C to Li Hg Al Ga and Sn. Crystal Structures of [Li\{C(SiMe3)2(SiMe2NMe2)\}(THF)2] [Hg\{C(SiMe3)2(SiMe2NMe2)\}2] [Al\{C(SiMe3)2(SiMe2NMe2)\}X2] (X=Cl Ph) and [Ga\{c(SiMe3)2(SiMe2NMe2)\}Cl2] , 1999 .

[4]  A. Haaland,et al.  Molecular Structures of EtTiCl3 and EtTiCl3(dmpe) (dmpe = Me2PCH2CH2PMe2): New Insights into β-Agostic Bonding , 1998 .

[5]  P. Hitchcock,et al.  An Unusual Alkyltrihydroaluminate. Crystal Structures of [AlH2{C(SiMe3)2(SiMe2OMe)}(μ-H)Li(THF)], [AlCl2{C(SiMe2OMe)(SiMe3)2(THF)], and [Li{C(SiMe2OMe)(SiMe3)2}(THF)2] (THF = Tetrahydrofuran) , 1998 .

[6]  A. Hitchcock,et al.  A Novel Zwitterionic Species Containing an Aluminum(III) Cation and a Planar Carbanion. Crystal Structure of [Et3AlNMe2SiMe2C(SiMe2NMe2)2AlEt2]·C6H6 , 1998 .

[7]  W. Clegg,et al.  CRYSTAL STRUCTURE OF A HEAVIER ALKALI METAL DIISOPROPYLAMIDE COMPLEX : A DISCRETE (KN)2 RING DIMER WITH TMEDA CHELATION AND SHORT INTRAMOLECULAR K...H (C) CONTACTS , 1998 .

[8]  P. Schleyer,et al.  New chelating silylamido ligands: syntheses and X-ray crystal structures of lithium and magnesium derivatives of [t-Bu–HN–SiMe2–o-C6H4–X] (X=OMe, NMe2, CH2NMe2, CF3) , 1998 .

[9]  P. Hitchcock,et al.  An Alkyllithium Compound with a Free Planar Carbanion. The Crystal Structure of [Li(THF)4][C(SiMe2C6H4Me-o)3] , 1997 .

[10]  P. Hitchcock,et al.  Organometallic Compounds of the Alkali Metals with Phenylsilyl Substituents at the Carbanionic Center. Crystal Structures of LiC(SiMe3)2(SiMe2Ph)·Et2O, NaC(SiMe3)2(SiMe2Ph)·TMEDA, NaC(SiMe3)(SiMe2Ph)2·TMEDA, {LiCH(SiMe2Ph)2}2, RbC(SiMe2Ph)3, and CsC(SiMe2Ph)3(TMEDA = Tetramethylethylenediamine) , 1997 .

[11]  P. Hitchcock,et al.  {Tris[(dimethylamino)dimethylsilyl]methyl}magnesium Iodide. A Grignard Reagent without a Carbon−Magnesium Bond? , 1997 .

[12]  K. Izod,et al.  The First Structurally Authenticated σ-Bonded Organosamarium(II) Derivative and Its Reaction with Benzophenone , 1997 .

[13]  P. Hitchcock,et al.  Alkyl derivatives of europium(+2) and ytterbium(+2). Crystal structures of Eu[C(SiMe3)3]2, Yb[C(SiMe3)2(SiMe2CH=CH 2)]I·OEt2 and Yb[C(SiMe3)2(SiMe2OMe)]I·OEt2 , 1996 .

[14]  C. Eaborn,et al.  Compounds of elements of Groups 11–13 containing (Me3Si)3C, (PhMe2Si)3C or related ligands , 1996 .

[15]  P. Hitchcock,et al.  Iodo(methoxydimethylsilyl)bis(trimethylsilyl)methane: A reagent for the preparation of novel organometallic compounds. Crystal structures of Mg{C(SiMe3)2(SiMe2OMe)}2 and MgI2(OEt2)2 , 1996 .

[16]  D. Armstrong,et al.  Benzyl(trimethylsilyl)amidolithium: structural studies by ab initio mo and X-RAY crystallographic methods, and comparison with the known structures of dibenzyl and bis(trimethylsilyl) analogues , 1996 .

[17]  P. Hitchcock,et al.  Two Diorganopotassates: Crystal Structure of [K(C6H6)][K{C(SiMe3)2(SiMe2Ph)}2] , 1996 .

[18]  D. Stalke,et al.  STRUCTURAL VARIANCES IN THE HOMOLOGOUS SERIES OF DI-ALKALI-METALATED OCTAMETHYLCYCLOTETRASILAZANES , 1996 .

[19]  K. Izod,et al.  Synthesis, structure and reactions of organometallic compounds of Groups 1–3 containing bulky silicon-substituted alkyl groups , 1995 .

[20]  S. Bott,et al.  Three-Coordinate Aluminum Is Not a Prerequisite for Catalytic Activity in the Zirconocene-Alumoxane Polymerization of Ethylene , 1995 .

[21]  U. Behrens,et al.  Über Metallalkyl- and Arylverbindungen LIV. Neue Tripheny1methyl-Verbindungen des Kaliums: [KCPh3(PMDTA)], [KCPh3(DIGLYM]n und [KCPh3(THF)]n , 1995 .

[22]  M. Noltemeyer,et al.  Dilithium Derivatives of Bis(tert‐butyldimethylsilylamino)silanes as Building Units for Inorganic Ring Compounds , 1995 .

[23]  P. Hitchcock,et al.  The Synthesis and Crystal Structures of RbC(SiMe3)3 and CsC(SiMe3)3·3.5 C6H6: A One‐dimensional Ionic Solid and an Ionic Solid with a Molecular Structure , 1995 .

[24]  P. Hitchcock,et al.  Transformation of the bis(trimethylsilyl)methyl into a 1,3-diaza-allyl ligand. Synthesis and crystal structures of [] and [{UCl(μ-Cl)(L)(NR)}2][UCl2(L)(L′)]2[R = SiMe3; Ar = C6Me2-2,5; L = ; L′ = ] , 1995 .

[25]  P. Hitchcock,et al.  Metalation of Tris(trimethylsilyl)‐ and Tris(dimethylphenylsilyl)methane with Methylsodium: The First Dialkylsodate , 1994 .

[26]  M. Westerhausen,et al.  Tris(trimethylsilyl)silylamin und seine lithiierten und silylierten Derivate — Kristallstruktur des dimeren Lithium‐trimethylsilyl‐[tris(trimethylsilyl)silyl]amids , 1993 .

[27]  D. Stalke,et al.  Unexpected coordination of aminoiminophosphoranate ligands with alkali metals , 1993 .

[28]  U. Pieper,et al.  Cation-induced structural alterations in the organo alkali metal derivatives of triphenylmethane: a combined x-ray and NMR study of the potassium-cesium salts , 1993 .

[29]  U. Pieper,et al.  Syntheses and x-ray structures of (diphenylpyridylmethyl)lithium, -sodium, and -potassium in comparison with the triphenylmethyl derivatives , 1993 .

[30]  R. Mulvey.  Meldola Medal Lecture. Ring-stacking and ring-laddering in organonitrogenlithium compounds: the development of concepts with wide applicability throughout lithium structural chemistry , 1991 .

[31]  J. Huffman,et al.  Ion pairing in [bis(trimethylsilyl)amido]potassium: The x-ray crystal structure of unsolvated [KN(SiMe3)2]2 , 1990 .

[32]  C. Eaborn,et al.  Improvements in the preparation and use of [tris(trimethylsilyl)methyl]lithium , 1984 .

[33]  N. Wibeŕg,et al.  Erzeugung und Nachweis des Silaethens Me2SiC(SiMe3)2: Thermischer Zerfall von (Me3Si)2(Me2XSi)Cli (X z. B. Hal, OR, SR) , 1981 .

[34]  N. Wibeŕg,et al.  Auf dem Wege zum Silaethen Me2SiC(SiMe3)21): Trisilylierte Methane (Me3Si)2(Me2XSi)CY (X z. B. Hal, RO, RS; Y z. B. Br, Li) , 1981 .