Synthesis and crystal structure of NaCuIn(PO).

Single crystals of sodium copper(II) indium bis-[phosphate(V)], NaCuIn(PO), were grown from the melt under atmospheric conditions. The title phosphate crystallizes in the space group 2/ and is isotypic with KCuFe(PO). In the crystal, two [CuO] trigonal bipyramids share an edge to form a dimer [CuO] that is connected to two PO tetra-hedra. The obtained [CuPO] units are inter-connected through vertices to form sheets that are sandwiched between undulating layers resulting from the junction of PO tetra-hedra and [InO] octa-hedra. The two types of layers are alternately stacked along [101] and are joined into a three-dimensional framework through vertex- and edge-sharing, leaving channels parallel to the stacking direction. The channels host the sodium cations that are surrounded by four oxygen atoms in form of a distorted disphenoid.