ISSN:
0044-2313
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Metal Derivatives of Molecular Compounds. III. Molecular and Crystal Structure of Lithium bis(trimethylsilyl)phosphide · DME and of Lithium dihydrogenphosphide · DMELithium bis(trimethylsilyl)phosphide · DME 1 prepared from tris(trimethylsilyl)-phosphine and lithium methanide [2, 4] in 1,2-dimethoxyethane1,2-Dimethoxyethan (DME); Tetrahydrofuran (THF); Bis[2-(dimethylamino)ethyl]methyl-amin (PMDETA). , crystallizes in the orthorhombic space group Pnnn {a = 881.1(9); b = 1308.5(9); c = 1563.4(9) pm at -120 ± 3°C; Z = 4 formula units}, lithium dihydrogenphosphide · DME 2[10] prepared from phosphine and lithium- n-butanide in the same solvent, in P2 1 2 1 2 1{a = 671.8(1); b = 878.6(1); c = 1332.2(2) pm at -120 ± 3°C; Z = 4 formula units}. X-ray structure determinations (R w= 0.036/0.045) show the bis(trimethylsilyl) derivative 1 to be dimeric with a planar P—Li—P—Li ring (P—Li 256 pm; Li—P—Li 76°; P—Li—P 104°), and the dihydrogenphosphide 2 to be polymeric with a linear Li—P—Li fragment (P—Li 254 to 260 pm; Li—P—Li 177°; P—Li—P 118°). The shortened P—Si distance (221 pm) of compound 1 and the structure of the PH 2 group in 2 are discussed in detail. Lithium obtains its preferred coordination number 4 by a chelation with one molecule of 1,2-dimethoxyethane (Li—O 202 to 204 pm).
Notes:
Das aus Tris(trimethylsilyl)phosphan und Lithiummethanid in 1,2-Dimethoxyethan leicht zugängliche Lithium-bis(trimethylsilyl)phosphid · DME 1 [2, 4] kristallisiert orthorhombisch in der Raumgruppe Pnnn {a = 881,1(9); b = 1308,5(9); c = 1563,4(9) pm bei -120 ± 3°C; Z = 4 Formeleinheiten}, das aus Phosphan und Lithium-n-butanid im gleichen Solvens zu synthetisierende Lithium-dihydrogenphosphid · DME 2 [10] in P212121 {a = 671,8(1), b = 878,6(1); c = 1332,2(2) pm bei -120 ± 3°C; Z = 4 Formeleinheiten}. Nach den Ergebnissen von Röntgenstrukturanalysen (Rw = 0,036/0,045) liegt das Bis(trimethylsilyl)-Derivat 1 dimer mit planarem P—Li—P—Li-Ring (P—Li256 pm; Li—P—Li 76°; P—Li—P 104°), die Wasserstoff-Verbindung 2 polymer mit linearem Li—P—Li-Fragment (P—Li 254 und 260 pm; Li—P—Li 177°; P—Li—P 118°) vor. Der verkürzte P—Si-Abstand (221 pm) in Verbindung 1 und die Geometrie der PH2-Gruppe in 2 werden eingehender diskutiert. Die von Lithium bevorzugte Koordinationszahl 4 wird durch den Chelatliganden 1,2-Dimethoxyethan (Li—O 202 bis 204 pm) erreicht.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19895770103
