Hydrothermal synthesis and structural characterization of a nickel(II) Vanadyl(IV) phosphate hydrate: Ni0.5VOPO4 · 1.5H2O

Synthesis and Crystal Structure of a Novel Lamellar Barium Derivative: Ba(VOPO4)2·4H2O. Synthetic Pathways for Layered Oxovanadium Phosphate Hydrates M(VOPO4)2·nH2O

“…In fact, they have been extensively applied to the isolation and crystal growth of M x -VOPO 4 ‚nH 2 O (M ) Na + , K + , Rb + , Ca 2+ , Sr 2+ , Pb 2+ , Co 2+ , Ni 2+ and Cu 2+ ) solids. [11][12][13][14][15][16] However, problems like poor yields and polyphasic products are common facts in the syntheses described in the bibliography. Really, exception made for one of the syntheses described for the nickel derivative, 13 all the remaining solids (M ) Ca 2+ , Sr 2+ , Pb 2+ , Co 2+ , and Cu 2+ ) [12][13][14][15] have been obtained as mixtures of phases and even as minor reaction products.…”

“…[11][12][13][14][15][16] However, problems like poor yields and polyphasic products are common facts in the syntheses described in the bibliography. Really, exception made for one of the syntheses described for the nickel derivative, 13 all the remaining solids (M ) Ca 2+ , Sr 2+ , Pb 2+ , Co 2+ , and Cu 2+ ) [12][13][14][15] have been obtained as mixtures of phases and even as minor reaction products. Moreover, the diversity of unrelated synthetic procedures to obtain chemically and structurally similar products seems rather unsatisfactory.…”

“…From a structural point of view, it can be noted that the use of solid state synthetic techniques or hydrothermal procedures under moderately hard conditions ( T > 250 °C) results in a diversity of anhydrous condensed phosphates (or arsenates) , and tunneled networks − K 2 (VO) 2 P 3 O 9 (OH) 3 ·1.125H 2 O, BaVO(AsO 4 )(H 2 AsO 4 )·H 2 O, Ba 2 VO(PO 4 ) 2 ·H 2 O, Ba 8 (VO) 6 (PO 4 ) 2 (HPO 4 ) 11 ·3H 2 O, and BaVO(PO 4 )(HPO 4 ) H 2 O …”

“…From a structural point of view, it can be noted that the use of solid state synthetic techniques or hydrothermal procedures under moderately hard conditions (T > 250 °C) results in a diversity of anhydrous condensed phosphates (or arsenates) 8,9 and tunneled networks. 10 On the contrary, the syntheses performed under soft hydrothermal conditions usually lead to open frameworks (generally of lamellar morphology) including hydration water molecules, as occurs for M(VOPO 4 ) 2 ‚nH 2 O (n ) 4, M ) Na, Ca, Sr, Pb, Co, Ni, Cu; n ) 3, M) K, Rb, Pb, Ni), [11][12][13][14][15][16] K 2 (VO) 2 P 3 O 9 -(OH) 3 ‚1.125H 2 O, 17 BaVO(AsO 4 )(H 2 AsO 4 )‚H 2 O, 18 Ba 2 VO-(PO 4 ) 2 ‚H 2 O, 19 Ba 8 (VO) 6 (PO 4 ) 2 (HPO 4 ) 11 ‚3H 2 O, 20 and BaVO-(PO 4 )(HPO 4 ) H 2 O. 21 Among these last solids, the layered oxovanadium phosphate hydrates M(VOPO 4 ) 2 ‚4H 2 O can be formally thought of as derived from the 2-D network of the VOPO 4 ‚2H 2 O: 2 All of them show the same lamellar topology of the parent structure, and the guest cations are located in the interlamellar space.…”

Ein aus Oktaedern, quadratischen Pyramiden und Tetraedern aufgebauter Festkörper mit Vanadiumphosphat‐Gerüst und einem Hohlraumdurchmesser von 18.4 Å

“…Der V"'-V'"-Abstand der Iangeren Ellipsenachse der Kanale entspricht mit 18. 4 A der Lange der Elementarzelle entlang der c-Achse. Die polaren NHl-Enden der organischen Kationen und das Kristallwasser sind innerhalb der Hohlraume so positioniert, daB die Wasserstoffbriickenbindungen mit den polaren P-OH-und V (H,O),-Geriisteinheiten maximiert werden, wahrend das weniger polare Kohlenstoff-Riickgrat der organischen Template mit den V=O-Gruppen wechselwirkt.…”