Analyse des spectres de vibration infrarouge et Raman de benzothiazolines et de 2 H ‐chromènes, éléments constitutifs de spiropyrannes benzothiazoliniques. Aspect synthétique

Study of infrared and Raman spectra of benzothiazolines and 2 H ‐chromenes, constitutive parts of benzothiazolinic spiropyrans. Synthetic aspect. We have synthesized some benzothiazolines and some substituted 2 H ‐chromenes as models of the two halves of benzothiazolinic spiropyrans with the aim of interpretation of infrared and Raman spectra of spiropyranic structure. While doing that, we have been able to improve the synthesis method of chromenes obtained from coumarins and we have prepared new nitro‐chromenes. By studying IR. and Raman spectra of the two halves of spiropyranic molecule, we could propose a rather good attribution of fondamental modes of vibration. This attribution will used as base for the interpretation of IR. and Raman spectra of a series a benzothiazolinic spiropyrans.