ISSN:
0009-2940
Keywords:
Lithium N,N'-diethylhydrazide hexamer
;
Dilithium N,N'-bis(trimethylsilyl)hydrazide tetramer
;
[Lithium N,N-bis(trimethylsily)hydrazide]-[dilithium N,N'-bis(trimethylsilyl)hydrazide] dimer
;
Dilithium N-phenyl-N-trimethylsilylhydrazide tetramer
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Deprotonation of NH protons, of four diorgano-, organo(trimethylsilyl)- and bis(trimethylsilyl)hydrazines by n-butyllithium in hexane led to the following lithium hydrazides: [Et-(Li)N-N(H)Et]6, (1)6, [Me3Si(Li)N-N(Li)SiMe3]4, (2)4, [Me3Si-(Li)N-N(Li)SiMe3 · (Me3Si)2N-N(Li)SiMe3]2 (3)2, and [Ph-(Li)N-N(Li)SiMe3]4, (4)4, respectively. The structure determination by X-ray methods at low temperature reveals butterfly-shaped Li2N2 structural monomeric units which associate through “laddering” to the observed oligomers thereby generating penta- and hexacoordinated Li centers. N-N bonds lengths of up to 1.556 Å suggest that negative charge accumulates at the nitrogen atoms of (1)6, (2)4, and (3)2. An amazing structure shows the red compound 4 where two Li ions are π-sandwiched between two phenyl groups each. The compound can be looked at as a new type of a lithium lithiate complex, Li2[Li6N8Ph4(SiMe3)4], but short N-C and N-N bonds in the Li6N8 core indicate that its negative charge is transferred to the phenyl groups.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19951280204