Crystal structure of tetramethylammonium fluoridotitanate(IV) with dimeric complex anions of different compositions

Abstract

To the best of our knowledge, this is the first report of the synthesis and characterization of tetramethylammonium fluoridotitanate(IV) [N(CH3)4]4[Ti2F11][Ti2F9(H2O)2] with two dimeric complex anions of different compositions. The disordered crystal structure of [N(CH3)4]4[Ti2F11][Ti2F9(H2O)2] is formed by dimeric complex anions [Ti2F11]3− and [Ti2F9(H2O)2]− in a 1:1 ratio and tetramethylammonium cations N(CH3)4+, each with an occupancy factor of 0.5. The dimeric complex anions, which structurally alternate with an occupancy factor of 0.5, form a pseudodimeric anion {(Ti2F11)0,5(Ti2F9(H2O)2)0,5}2− whose charge is compensated by the disordered cations N(CH3)4+. The hydrogen bonds O-H⋯F link the dimeric complex anions [Ti2F11]3− and [Ti2F9(H2O)2]− into polymeric ribbons, with the N(CH3)4+ cations being located between the ribbons.