Synthesis and study of tetramethylammonium hexafluoridozirconate and hexafluoridohafnate solvated by H2O·HF adducts and [N(CH3)4]2ZrF6

► A new type of zirconium and hafnium fluoride complexes of the composition [N(CH3)4]2AF6·(H2O·HF) (A = Zr, Hf) solvated by H2O·HF adducts and the compound [N(CH3)4]2ZrF6 have been synthesized. ► The compounds were studied by means of X-ray diffraction, IR and Raman spectroscopy, thermogravimetry and quantum chemistry methods. ► The structural change during the desolvation of [N(CH3)4]2ZrF6·(H2O·HF) has been investigated.