Intramolekulare Lithium‐Bewegungen im Kristall

Veith, Michael; Zimmer, Michael; Fries, Kira; Böhnlein‐Maus, Jutta; Hüch, Volker

doi:10.1002/ange.19961081332

Cited by 11 publications

(7 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The overall point symmetry of this movement must be at least compatible with D 2 d (−42m), which is possible only if the lithium atoms are involved in the molecular dynamics. It can be anticipated that these movements should be similar to the ones observed in the crystalline derivative 1 . It should, however, be pointed out that during these dynamic rearrangements, bond closures and openings should also be taken into account.…”

Section: Introductionmentioning

confidence: 63%

“…Lithium atoms with a formal positive charge of +1 have been shown to be easily moved in ionic solid materials such as Li 3 N when the crystal is brought in an electric field. , This lithium conduction, which is useful for solid-state batteries, is connected to a lithium mobility . Recently, we were able to show that lithium mobility can also be encountered in crystals of a special lithium amide [tBuO−SiMe 2 −N−SiMe 2 −OtBu] 2 Li 2 ( 1 ) …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Lithium Coordination in Chelating Silazanes of the General Formula [X−Me₂Si−N−SiMe₂−X]₂Li₂

et al. 1998

Self Cite

View full text Add to dashboard Cite

New derivatives of hexamethyldisilazanelithium of the general formula [X−Me2Si−N−SiMe2−X]2Li2 (X = Ph (2), C4H3S (3), NMe2 (4), NEt2 (5), N(H)iPr (6), OPh (7), OSiMe3 (8), C4H3O (9)) have been synthesized and characterized by spectroscopic means. All compounds except 3 have been subjected to X-ray structure determinations which reveal a common polycyclic arrangement with a central Li2N2 four-membered ring to which four similar LiNSiY rings are annealed along a common Li−N edge (Y can either be a carbon atom of a π-system (2, 3), nitrogen (4−6) or oxygen (7−9)). The common four-membered polycyclic skeleton Li2N2Si4Y4 has a point symmetry of approximately D 2 (222) of which only C 2 (2) symmetry is retained in the crystals of 4, 5, 6, and 9, whereas all other derivatives have point symmetry C 1 (1). One of the compounds crystallizes in one enantiomeric form (4) in an acentric structure. All other compounds crystallize in centrosymmetric structures with the two enantiomers present in the crystal. The lithium atoms in 2−9 are present in a distorted tetrahedral environment constituted by two nitrogen and two Y atoms. From molecular mass determinations, the compounds seem to retain their dimeric nature in benzene, the NMR patterns being nevertheless more simple than expected from the crystal structures and indicate a dynamic behavior in solution. None of these compounds, so far, shows lithium motion in the solid state up to room temperature, although phase transitions seem to occur in compound 8 at higher temperatures (13C SPE/MAS NMR evidence). Li−N distances in the central Li2N2 ring depend on the nature of donor groups Y: short Li−N bonds (2.024 Å) are found for the lithium atoms coordinated by organic π-systems together with relatively long Li−C bonds (2.53 Å in 2), whereas longer Li−N bonds (2.07−2.085 Å) are encountered for the nitrogen donors with short Li−N “donor” bonds (2.157 (4), 2.163 (5), 2.121 Å (6)). If the donor atom (Y) is oxygen, the Li−O bonds can be either shorter than the Li−N bonds (7, Li−N 2.073, Li−O 1.978 Å; 9, Li−N 2.076, Li−O 1.977 Å) or slightly longer (8, Li−N 2.021, Li−O 2.077 Å). It is remarkable that in the trimethylsilyloxy case 8 the Li−N distances are not equal within their standard deviations as observed in the other cases: two distances (average 1.96 Å) on opposite sides of the Li2N2 ring are much shorter than the remaining two (average 2.08 Å).

show abstract

Section: Introductionmentioning

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Lithium Coordination in Chelating Silazanes of the General Formula [X−Me₂Si−N−SiMe₂−X]₂Li₂

et al. 1998

Self Cite

View full text Add to dashboard Cite

show abstract

“…Our idea was to generate such thermodynamically unstable compounds by using a further intramolecular nucleophilic ligand to raise the coordination number at the germanium or tin atom. For this purpose we have synthesized a variety of silazanes (13, 14, 15, Scheme 10) which consist, apart from the N-H groups used for bonding to germanium or tin atoms, of basic atoms (nitrogen or oxygen) [27][28][29].…”

Section: Base Stabilized Bis(amino)germaimines and -Thiones And The Cmentioning

confidence: 99%

“…Before bonding to germanium or tin, the amines 13-15 must first be converted to the corresponding lithium derivatives. The lithium derivatives of 13 and 15 have been isolated and structurally characterized by X-ray diffraction [27,29].…”

Section: Base Stabilized Bis(amino)germaimines and -Thiones And The Cmentioning

confidence: 99%

See 1 more Smart Citation

Metal centered molecules and their application in chemistry and physics

Veith¹,

Rammo²,

Faber³

et al. 1999

Pure and Applied Chemistry

View full text Add to dashboard Cite

Monocyclic as well as polycyclic silylamides of a series of main group metals such as Li, Ge, Sn and Pb (the last three elements mostly in the oxidation state þII) have been synthesized, analyzed by spectroscopic means and structurally characterized over the last 20 years. All these molecular compounds have in common a Lewis acidic (electrophilic) metal center with at least one bond to nitrogen. In the case of the bis(amino)germylenes, -stannylenes and -plumbylenes, the metal centers are poorly coordinated (only two bonds to nitrogen) and may directly react with organic -systems. This nonclassical behaviour will be discussed shortly. If the metal atoms are more highly coordinated by intramolecular nitrogen or oxygen bases, the oxidation to stable germaimines or germathiones is possible, whereas the corresponding tin compounds are only transient in nature. Finally, the use of special metal alkoxides [for example Ge(OtBu)

show abstract

Special Siloxamides: Metal Movements in a Crystalline Molecular Box

Veith

2000

Eur. J. Inorg. Chem.

Self Cite

View full text Add to dashboard Cite

Intramolekulare Lithium‐Bewegungen im Kristall

Cited by 11 publications

References 10 publications

Lithium Coordination in Chelating Silazanes of the General Formula [X−Me₂Si−N−SiMe₂−X]₂Li₂

Lithium Coordination in Chelating Silazanes of the General Formula [X−Me₂Si−N−SiMe₂−X]₂Li₂

Metal centered molecules and their application in chemistry and physics

Special Siloxamides: Metal Movements in a Crystalline Molecular Box

Contact Info

Product

Resources

About

Intramolekulare Lithium‐Bewegungen im Kristall

Cited by 11 publications

References 10 publications

Lithium Coordination in Chelating Silazanes of the General Formula [X−Me2Si−N−SiMe2−X]2Li2

Lithium Coordination in Chelating Silazanes of the General Formula [X−Me2Si−N−SiMe2−X]2Li2

Metal centered molecules and their application in chemistry and physics

Special Siloxamides: Metal Movements in a Crystalline Molecular Box

Contact Info

Product

Resources

About

Lithium Coordination in Chelating Silazanes of the General Formula [X−Me₂Si−N−SiMe₂−X]₂Li₂

Lithium Coordination in Chelating Silazanes of the General Formula [X−Me₂Si−N−SiMe₂−X]₂Li₂