The inverse podant [Li3(NBut)3S}]+ stabilises a single ethylene oxide OCH=CH2 anion as a high- and low-temperature polymorph of [(thf)3Li3(OCH=CH2){(NBut)3S}]

A single ethylene oxide anion derived from the ether cleavage reaction of thf with (BuLi)-Li-t is stabilised by the inverse podant [Li-3(NBut)(3)S}](+) to give a high- and a low-temperature polymorph with a considerable difference in conformation and packing.