Hydrogen O–H⋯F Bonds in the Crystals of MTiF₆·6H₂O (M = Mn, Co, Ni, Zn)

Single crystals of hexahydrates of divalent fluoridotitanates MTiF₆·6H₂O (M = Mn, Co, Ni, Zn) are synthesized. Their crystal structures are determined by X-ray diffraction at room temperature (RT-structure) and below the phase transition (LT structure). The phase transition is accompanied by a transformation of the disordered trigonal lattice into the ordered monoclinic one. The initial RT-structures differ in the set and strength of O–H⋯F hydrogen bonds linking isolated [M(H₂O)₆]²⁺ and [TiF₆]^2– octahedra into a 3D framework. There is a correlation between the strength of hydrogen bonds and the thermal behavior of the complexes.