Ring systems incorporating the ambidentate dianions [(BuN)-Bu-t(E)P(mu-(NBu)-Bu-t)(2)P(E)(NBu)-Bu-t](2-)(E = S, Se)

摘要

Alkali metal derivatives of the ambidentate dianions [(BuN)-Bu-t(E)P(mu -(NBu)-Bu-t)(2)P(E)(NBu)-Bu-t](2-)(E = S, Se) are readily prepared by metallation of the diprotonated precursors with (LiBu)-Bu-t or MN(SiMe3)(2) (M = Na, K). In the dilithiated derivative the dianion adopts a his-chelated (N,S) bonding mode involving four-membered (LiNPS) over bar rings. By contrast, the structures of disodium and dipotassium derivatives reveal a preference for the formation of six-membered (MNPNPN) over bar and (MEPNPE) over bar rings. [References: 8]