Syntheses and Structural Characterization of A₃Sb₃P₂O₁₄⋅3H₂O (A=Rb, Cs, Tl and NH₄) Phosphates; Facile Aqueous Ion Exchange Reactions of K₃Sb₃P₂O₁₄⋅3H₂O

Abstract

Four quaternary phosphates of antimony, A3Sb3P2O14⋅3H2O (A=Rb, Cs, Tl and NH4) have been prepared by solid state and hydrothermal reactions and structurally characterized by single crystal and powder X‐ray diffraction techniques. They are isostructural with reported K3Sb3P2O14⋅3H2O compound and all five of them have layered structure, wherein the hexagonal‐tungsten‐oxide (HTO) related (Sb3P2O14)3− anionic layers are interleaved with the A+ ions and water of crystallization. K3Sb3P2O14⋅3H2O undergoes topotactic ion‐exchange reactions with aqueous solutions of ACl (A=Rb, Cs, Tl, NH4) salts, almost quantitatively.

Syntheses, Crystal Structure, and Second Harmonic Generation Response of Noncentrosymmetric Layered Selenites and Tellurites of Antimony(V), ASb3X2O12 (A = K, Rb, Cs, Tl; X = Se, Te)

“…Another oxyfluoride, KGa 3 Se 2 O 6 F 6 , is reported to crystallize in the centrosymmetric R 3̅ m space group and have a similar HTO-related layered structure, in which GaO 2 F 4 intraoctahedral distortion is symmetric tetragonal D 4h compression. It is noteworthy that the VO 6 and SbO 6 octahedral distortions in the centrosymmetric HTO-related layered structures of (CN 3 H 6 ) 2 (VO 2 ) 3 (PO 4 )­(HPO 4 ) and A 3 Sb 3 P 2 O 14 ·3H 2 O (A = K, Rb, Cs, Tl) phosphates are C 2 and symmetric tetragonal elongation D 4h , respectively. − …”

“…16,17 These four antimony(V) phosphates, synthesized at high temperatures by solid-state reactions, have a centrosymmetric layered structure, in which A + ions and H (CN 3 H 6 ) 2 (VO 2 ) 3 (PO 4 )(HPO 4 ) is a phosphate of vanadium-(V) reported 18 to be obtained under hydrothermal conditions and its structure has similar centrosymmetric HTO related [V 3 P 2 O 13 (OH)] 2− anionic layers, which are interleaved with guanidinium cations. In view of the ease of solid state synthesis of these four HTO-related antimony(V) phosphates 16,17 and also their structural similarity to quaternary selenites, 7−11 tellurite, 5 and phosphate 18 20 were prepared in polycrystalline form from mixtures of appropriate reactants, Rb 2 CO 3 , Tl 2 CO 3 , Sb 2 O 4 , and Te(OH) 6 . The details of temperature and duration of heating and cooling, reactants, and their quantities for the synthesis and crystal growth are presented in Tables S1 and S2.…”

“…In this context, it is noteworthy that (CN 3 H 6 ) 2 (VO 2 ) 3 (PO 4 )(HPO 4 ) is a phosphate of vanadium(V) reported to be obtained under hydrothermal conditions and its structure has similar centrosymmetric HTO related [V 3 P 2 O 13 (OH)] 2– anionic layers, which are interleaved with guanidinium cations. In view of the ease of solid state synthesis of these four HTO-related antimony(V) phosphates , and also their structural similarity to quaternary selenites, − tellurite, and phosphate of vanadium(V), similar ASb 3 Se 2 O 12 selenites and ASb 3 Te 2 O 12 tellurites (A = alkali metal, Tl) of antimony(V) were envisaged. A preliminary study of solid state syntheses and structural characterization, by powder X-ray diffraction, of ASb 3 Te 2 O 12 (A = Cs, Rb, Tl) tellurites revealed that they are indeed structurally similar to layered CsV 3 Te 2 O 12 .…”

“…The Sb 5+ ion is a d 10 cation and known to have stable octahedral coordination in oxides such as A 3 Sb 3 P 2 O 14 ·3H 2 O (A = K, Rb, Cs, Tl) compounds. , These four antimony­(V) phosphates, synthesized at high temperatures by solid-state reactions, have a centrosymmetric layered structure, in which A + ions and H 2 O molecules reside between HTO-related [Sb 3 P 2 O 14 ] 3– layers. In this context, it is noteworthy that (CN 3 H 6 ) 2 (VO 2 ) 3 (PO 4 )­(HPO 4 ) is a phosphate of vanadium­(V) reported to be obtained under hydrothermal conditions and its structure has similar centrosymmetric HTO related [V 3 P 2 O 13 (OH)] 2– anionic layers, which are interleaved with guanidinium cations.…”