Syntheses and characterization of phosphonates and diphosphonates of molybdenum, A4[(MoO3)5(O3PR)2]·xH2O, A2[Mo2O5(O3PR)2] and A2[Mo2O5(O3P-R-PO3)] (A = K, Rb, Cs, Tl, NH4)

Abstract

Twenty new molybdenum phosphonates and diphosphonates have been synthesized and structurally characterized by single crystal and powder X-ray diffraction, CHN analyses, spectroscopic and thermal studies. Four of them are molecular phenyl- and benzyl-phosphonates containing discrete [(MoO₃)₅(O₃PR)₂]⁴⁻ (R = Ph or CH₂Ph) cyclic anions. The sixteen non-molecular compounds are layered isostructural phenylphosphonates, A₂[Mo₂O₅(O₃PPh)₂] (A = NH₄, Tl, Rb, Cs) and K_1.5(H₃O)_0.5[Mo₂O₅(O₃PPh)₂] and the corresponding diphosphonate compounds with pillared anionic layers, A₂[Mo₂O₅(O₃P(CH₂)₃PO₃)], A₂[Mo₂O₅(O₃P(CH₂)₄PO₃)] and A₂[Mo₂O₅(O₃P(C₆H₄)PO₃)]. The A⁺ ions reside in the interlayer region as well as in the cavities within the anionic layers.