Lithium complexes supported by tripodal diaminebis(aryloxido) ligands: Synthesis and structure

摘要

The diaminebis(aryloxido) ligand precursors H _2L ~1 and H _2L ~2 [H _2L ~1 = Me _2NCH _2CH _2N(CH _2-4-CMe _2CH _2CMe _3-C _6H _3OH) _2; H _2L _2 = Me _2NCH _2CH _2N(CH _2-4-Me-C _6H _3OH) _2] were synthesized by a straightforward single-step Mannich condensation. Their reactions with 2 molar equivalents of MeLi in thf afforded [Li _4(μ-L- κ ~4O,N,N,O) _2(thf) _2] (1a, L ~1; 1b, L ~2) and unexpectedly small amounts (～9%) of [Li _6(μ-L-κ ~4O,N,N,O) _2(μ ~3-Cl) _2(thf) _4].thf (2a.thf; L ~1; 2b.thf, L ~2). Stoichiometric reactions of LiCl, MeLi and ligand precursors H 2L led to the formation of 2a and 2b in high yield (～80%). All compounds were characterized by chemical and physical techniques including X-ray crystallography for H _2L ~1, H _2L ~2, 1b, 2a and 2b.