Structural Diversity of Lithium N-Mesityl-P,P-diphenylphosphinimidate of the type [(L)Li{O-PPh2=N-Mes]n Depending on Lewis Base L

Metalation of N-mesityl-P,P-diphenylphosphinic amide with nBuLi in toluene yields tetranuclear lithium N-mesityl-P,P-diphenylphosphinimidate ([Ph2P(OLi)=N-Mes](4), 1). Metalation of Ph2P(O)-N(H)Mes with a mixture of dibutylmagnesium and butyllithium in DME leads to formation of dinuclear [Ph2P{OLi(dme)}=N-Mes](2) (2). Excess of Ph2P(O)-N(H)Mes gives dinuclear [Li(O-PPh2=N-Mes){Ph2P(=O)-N(H)-Mes}](2) (3) with three-coordinate alkali ions. The metathetical approach via reaction of 1 with anhydrous magnesium bromide in ethereal solution yields [{(thf)LiBr}(2){(thf)Li(O-PPh2=NMes)(Et2O)Li(O-PPh2=NMes)}] (4). Heterobimetallic Li/Mg compounds are not accessible by these protocols. Reactions of 1 with DME, with excess of Ph2P(O)-N(H)Mes or with LiBr allows the straightforward conversion to compounds 2, 3 and 4.

Automated summary

This study investigates the formation of complexes from the reaction of N-mesityl-P,P-diphenylphosphinic amide with different metal reagents, including tetranuclear lithium complex, dinuclear complex, and trinuclear alkali ion complex. It also explores the method of converting to heterobimetallic compounds through reaction transformation.