New investigation on THz spectra of OH and SH radicals (X2∏i)

► Complementarity between broadband synchrotron-based FT-FIR and cw-THz techniques. ► Pure rotational transitions of radicals within their firsts vibrational states. ► Resolution of hyperfine structure of SH radical above 1 THz. ► Resolution of hyperfine structure of OH radical using FT-spectroscopy.