Abstract
The NMR spectra of different types of sulphur‐containing indigoid dyes as leuco forms (i.e. reduced forms or ‘vats’) in deuterium oxide are recorded and discussed. NMR spectroscopy provides an expeditious technique for identification, structure elucidation and purity control of these dyes. The regio‐selective exchange of halogen for deuterium or hydrogen in indigo derivatives was successfully adapted to thioindigos and [indole‐(2′)]‐[thionaphthene‐(2)]‐indigos. The reaction is useful as supplementary method for structure analysis and renders access to new selectively deuterated dyes. Care must be observed with the concentration of reducing agents and pH values in vat dyeing process in order to avoid further reduction of the leuco forms. The ‘overreduction’ of leuco forms of [acenaphthene‐(1′)]‐[thionaphthene‐(2)]‐indigos was followed by NMR spectroscopy and interpreted.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
