Quartet 7 coupling evolution

Sodium and potassium carbonates were found to dissolve in 1 1 HS03F—SbF6 at — 78° without the evolution of carbon dioxide (Olah and White, 1968). A single low field peak in the proton n.m.r. spectrum was assigned to C(OH) j", protonated carbonic acid. On warming the solution the peak disappeared and was replaced by another peak characteristic of water in this medium and carbon dioxide was evolved. The assignment of the low field peak to C(0H) J was confirmed by observation of the C13 spectrum which proved to be the expected quartet due to coupling with the three equivalent protons. 

Figure 5. CASSCF collinear evolution of spin-orbit couplings between (a) doublet-doublet, quartet-quartet and (b) doublet-quartet electronic states of CC>2+, where the other CO distance is kept fixed at the equilibrium geometry of the neutral molecule (i.e. 2.2 Bohr). See Table 1 for the definition of these terms. Strictly speaking, the g-u symmetry is only applicable for Rco = 2.2 Bohr.

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