Synthesis and crystal structure of Na₅Cu₃(PO₄)₂(PO₄HPO₄)

Abstract

Crystals of Na5Cu 3 (P0 4 ) 2 (P04HP04) were synthesized under hydrothermal conditions. The crystal structure was solved by Patterson methods and was refined to R w = 0.045 (a = 5.106(2) Ä, b = 8.409(3) Ä, t· = 9.052(3) Ä, α = 115.76(3)°, β = 90.09(3)°, y = 106.01(3)°, space group Pi, Ζ = 1). The two crystallographically different Cu atoms display "square planar" coordination; one of them has a fifth Ο atom neighbour with Cu -Ο at 2.183 Ä. Two of the four phosphate groups per formula unit are connected by an extreme short (symmetry restricted) hydrogen bond with O. . .O at 2.388 Ä.

An uncommon Cu[2+4]O6 coordination polyhedron in the crystal structure of KCu3(OH)2[(AsO4)H(AsO4)] (with a comparison to related structure types)

“…Comparable connections of two alkaline earth coordination polyhedra with common O -O edges representing very short hydrogen bonds were determined in a few compounds Na5Cu3(X04)2[(X04)H(X04)] with X = P: 0...0 = 2.388(7) Â (Effenberger, 1985a), X = As: 0...0 = 2.427(4) Â (Effenberger, 1987a) (001). It is possible to derive such a layer from a Mg(OH) 2 (brucite) layer in whitch 1/4 of the "octahedral" positions are vacant; instead of the missing "octahedrally" coordinated atom, at both sides of the sheet an As0 4 tetrahedron is linked to three oxygen atoms (Fig.…”

The crystal structure of monoclinic Ag5Cu3(PO4)2[(PO4)H(PO4)]and its relationship to the triclinic sodium analogue

“…Recently the crystal structures of the compound Na 5 Cu 3 (P0 4 )2[(P0 4 )H-(P0 4 )] and isotypic arsenate were determined by single crystal X-ray techniques (Effenberger, 1985. Both compounds show three interesting crystal chemical features: (i) one Cu(II) atom has a tetragonal pyramidal [4 + 1] coordination with a "short" fifth Cu -Ο bond; (ii) one part of the X0 4 groups (X = P, As) is connected to dimers by very short symmetrically restricted hydrogen bonds; (iii) in addition the configuration Ο -Η -Ο is simultaneously a common edge of two Na polyhedra.…”

“…The most relevant details on the crystal structures of NAP and NAS have been described by Effenberger (1985. The most relevant details on the crystal structures of NAP and NAS have been described by Effenberger (1985.…”