Solution Structure of Succinylacetone, An Unsymmetrical β-Diketone, As Studied by 13C NMR and GIAO−DFT Calculations
摘要:
The enolization degrees of succinylacetone, an important heme biosynthesis inhibitor, have been determined in CDCl3 and water solutions using H-1 NMR. The solution structures of SA have been investigated using a combined NMR/theoretical [GIAO DFT PBE1PBE/16-311++G(2d, p) PCM] approach. The populations of both enolic forms undergoing enol-enol equilibriums for SA and a series of unsymmetrical beta-diketones have been established by a quantitative comparison of the experimental C-13 NMR chemical shifts and calculated shielding constants. Moreover, using the same method and considering various trial structures differing in conformation and/or hydration of neutral SA molecule as well as its monoanion and dianion the structures of the most abundant species being present in the investigated water solutions have been deduced.