Synthesis and crystal structure of bis(12-crown-4)lithium bis[N,N′-bis(trimethylsilyl)benzenesulphinamidino]lithiate(1–-); the first observation of three different lithium-7 environments in high-resolution solid-state NMR spectroscopy

Frank Pauer,Dietmar Stalke,João Rocha

doi:10.1039/c39910001477

Abstract

[Li(12-crown-4)2]+[Li({N(SiMe3)}2SPh)2]–1 is the product of the reaction of Me3SiNSNSiMe3 with phenyllithium using 12-crown-4 as a donor and has an ion-separated structure which is unique for alkali metal sulphinamidino derivatives; at room temperature 1 undergoes a phase transformation, and a preliminary examination of this process by high-resolution solid-state 7Li NMR spectroscopy shows, for the first time, the presence of three resolvable resonances.

Highlights

Sulphinamidino alkali metal compounds are widely used in main group and transition metal chemistry.’-5 The reason for using the sulphinamidino ligand is the good solubility of the products in hydrocarbons and its similar steric demand as those of the cyclopentadienyl ligand
The two SN2Li four-membered rings are on opposite sides of the central M2Nzfour-membered ring. Both this stair shaped tricycle in bs and the eight-membered ring in c have Cisymmetry. In this communication we report a further, new and distinct structural type obtained by the reaction of bistrimethylsilyl sulphur diimide with phenyllithium, using the cyclic ether 12-crown-4 as a donor for the lithium atom.?
After cooling to room temperature, crystals began to grow in the crown ether phase

Summary

Introduction

Sulphinamidino alkali metal compounds are widely used in main group and transition metal chemistry.’-5 The reason for using the sulphinamidino ligand is the good solubility of the products in hydrocarbons and its similar steric demand as those of the cyclopentadienyl ligand. In this communication we report a further, new and distinct structural type obtained by the reaction of bistrimethylsilyl sulphur diimide with phenyllithium, using the cyclic ether 12-crown-4 as a donor for the lithium atom.? [Li(12-crown-4)2][Li({N(SiMe3)}2SPh)2]1 has been shown by X-ray crystallography$ to form a solvent-separated ion-pair structure with one lithium atom in the anion (Fig. 1);only one other related [RLiRI- structure is known.[9] Li(1) is coordinated to two {N(SiMe3)}2SPhligands giving overall a singly charged anion.

Results

Conclusion