Accession Number : ADA288870

Title :   Isolation and X-Ray Crystal Structures of Li?mu 2-As(SiMe3)2MU 3-As(SiMe3)2(THF)2 and (Me3Si)2AsLiTHF)22.

Descriptive Note : Technical rept.,

Corporate Author : DUKE UNIV DURHAM NC DEPT OF CHEMISTRY

Personal Author(s) : Jones, L. T., III ; McPhail, A. T. ; Wells, R. L.

PDF Url : ADA288870

Report Date : 07 DEC 1994

Pagination or Media Count : 20

Abstract : The lithium arsenides (Li2MU2-As(SiMe3)2MU3-As(SiMe3)2(THF))2 (I) (THF = tetrahydrofuran) and (Me3Si)2AsLi(THF)22 (II) were isolated and their solid-state structures determined by X-ray methods. Compound I crystallizes in the monoclinic system, space group P2 sub 1/c, with a = 10.147(1) A, b = 19.665(2) A, c = 16.768(2) A, p = 107.78(1) and Z = 2. The core structure consists of an LiAs4 ladder-like framework with four antiparallel adjacent As-Li rungs. The two lithium atoms of the central ring each bridge three arsenic centers while the two lithium atoms belonging solely to the outer rings each span two arsenic atoms and are coordinated to one THF molecule. Monoclinic crystals of compound II belong to space group C2/c, with a = 17.877(4) A, b = 14.077(3) A, c = 19.006(4) A, p = 109.16(2) and Z = 4. The structure consists of a centrosymmetric dimer containing a four-membered As-Li-As-Li ring wherein each lithium atom is coordinated to two molecules of THF.

Descriptors :   *CRYSTAL STRUCTURE, *ISOLATION, *LITHIUM, *X RAY DIAGNOSTICS, *SILICON, *ARSENIDES, CORES, METHYL RADICALS, MOLECULES, CRYSTAL LATTICES, STRUCTURES, ATOMS, X RAYS, EXTERNAL, RINGS, ARSENIC, SOLID STATE CHEMISTRY, SOLID STATE ELECTRONICS, DIMERS, BRIDGES, FURANS, HYDROXYL RADICALS.

Subject Categories : Inorganic Chemistry
      Organic Chemistry
      Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE