Journal of the American Chemical Society, Vol.119, No.52, 12929-12933, 1997
H-1, C-13, N-15 NMR and ab initio IGLO GIAO-MP2 study of mono-, di-, tri-, and tetraprotonated guanidine
Mono- and diprotonated guanidines were prepared in superacid solutions and studied by H-1, C-13, and N-15 NMR spectroscopy. The structures, energies, and NMR chemical shifts were also calculated by ab initio/IGLO/GIAO-MP2 method. Excellent agreement were found between experimental and calculated C-13 and N-15 NMR chemical shifts. No persistent triprotonated guanidine was observed. Tri- and tetraprotonated guanidines were also studied by ab initio/IGLO/GIAO-MP2 method.