Dr. Armstrong et al., FIRST STRUCTURALLY CHARACTERIZED LITHIUM HEXAFLUOROPHOSPHATE COMPLEXES WITH ACYCLIC LEWIS-BASES - ION-SEPARATED [LI-2(HMPA)(5)](2-DOT-2(PF6-) AND ION-CONTACTED [(PMDETA)LIPF6](2) [HMPA = (ME2N)(3)PO - PMDETA =MEN(CH2CH2NME2)(2)]()CENTER), Chemical communications, (9), 1998, pp. 1011-1012
Reactions of NH4PF6 with (BuLi)-Li-n in toluene containing hmpa or pmd
eta afford the complexes [Li-2(hmpa)(5)](2+). 2(PF6)(-) 1, an ion-sepa
rated species containing an unusual dinuclear dication, and [(pmdeta)L
iPF6](2) in which PF6- anions bridge (pmdeta)Li+ units via Li ... F in
teractions, this being the first observation of a bridging mode for th
is anion; ab initio MO calculations help explain the very different st
ructures of 1 and 2.