Equivalent Li.cntdot..cntdot..cntdot.O and H.cntdot..cntdot..cntdot.O electronic effects in the lithium enolate of 1,3-cyclohexanedione

Organic−Organometallic Crystal Synthesis. 1. Hosting Paramagnetic [(η6-Arene)2Cr]+(Arene = Benzene, Toluene) in Organic Anion FrameworksviaOH···O and CH···O Hydrogen Bonds

“…This might be taken as indicative that the proton is removed exclusively from the CHD system and not from water, i.e., the crystal is composed of hydrated CHD - anions interacting with the organometallic cations. Interestingly, the structural parameters within the CHD moiety are strictly comparable to those observed in the lithium enolate crystals obtained by Etter from methanol and 2,2,2-trifluoroethanol solutions of Li-CHD (see Table ) . In both structures, the C−O as well as the inner C−C bonds have almost equal length, viz., removal of the enol proton leads to complete delocalization in the solid state, exactly as observed in structure 4 .…”

“…Interestingly, the structural parameters within the CHD moiety are strictly comparable to those observed in the lithium enolate crystals obtained by Etter from methanol and 2,2,2-trifluoroethanol solutions of Li-CHD (see Table 3). 34 In both structures, the C-O as well as the inner C-C bonds have almost equal length, viz., removal of the enol proton leads to complete delocalization in the solid state, exactly as observed in structure 4. However, it may be argued that the same bond length pattern in 4 can arise from static disorder, i.e., as a result of an average over space of CHD in keto-enol form as in 1 and 2.…”