DOI: 10.1002/poc.4043 

A theoretical and spectroscopic (NMR and IR) study of indirubin in solution and in the solid state

The infrared spectrum of indirubin in the solid state and the ¹H, ¹³C and ¹⁵N NMR spectra in DMSO‐d6 solution as well as the ¹³C and ¹⁵N CPMAS spectra have been recorded. Different types of calculations (B3LYP, GIAO, and GIPAW) have been carried out. Experimental and calculated values were compared yielding commensurate results. E/Z isomerism was explored, as was oxo/hydroxy tautomerism.