Structural Chemistry of Alkali Metal Phenylhyrazides

The crystal and molecular structures of a series of N ‐phenyl‐substituted lithium hydrazides were determined in order to investigate possible Li···Ph π interactions. These are pronounced when there are no donor molecules present to solvate the Li centers. An η 6 ‐Li···Ph interaction is particularly distinct in tetrameric (Me 3 Si) 2 N–N(Ph)Li but also in trimeric Ph 2 N–N(SiMe 3 )Li Deprotonation of N,N′ ‐diphenylhydrazine with butyllithium in ether resulted in the formation of Ph(Li)N–N(Ph)Li · 2 LiNPh 2 · 2 OEt 2 with phenyl group migration and N–N bond cleavage by a redox process. An increase of the size of the cations, as shown for Ph(Me 3 ‐Si)N–N(Ph)Na · NH 3 and the caesium salt (Me 3 ‐Si) 2 N–N(Ph)Cs · n THF, results in increased coordination of the metal ion to the phenyl group. The caesium compound forms a three‐dimensional network. Channels along the c axis are partially filled with THF molecules.