Intramolecular indium-nitrogen coordination. Synthesis and NMR study of four-coordinate [2-Me2NCH(Z)C6H4]Me2In and five-coordinate [2-Me2NCH(Z)C6H4]2InCl (Z = H or SMe)

Abstract

Arylindium compounds of the type ArJnCl and ArMezIn, in which the Ar group is either 2-Me2NCHzC6H4 or (S)-2-Me2NCH(Me)C6H4, have been synthesized by the organolithium route and characterized by 'H and 13C NMR spectroscopy. The NMR results clearly reveal that intramolecular In-N coordination occurs in solution, resulting in fivecoordinate ArzInCl and four-coordinate ArMezIn structures. In pyridine solution, the In-N bond in the four-coordinate ArMe21n compounds weakens as the result of the formation of a five-coordinate intermediate in which the NMe2 and pyridine ligand are in axial positions.