The synthesis and characterization of a new aluminophosphate, Na2Al2O(PO4)2·0.12H2O obtained as single crystals, is reported. Centrosymmetric tetramers built from AlO5 polyhedra sharing edges and vertices, represent the distinguished feature of the compound. These tetrameric units of AlO5 bipyramids are cross-linked by PO4 tetrahedra to form two-periodic slabs alternating with Na+ ions and a small amount of H2O molecules. The Na2Al2O(PO4)2·0.12H2O with an original crystal architecture is chemically and structurally related to the mineral tinsleyite, KAl2(PO4)2(OH)·2H2O. Similar clusters of Al-centered polyhedra are essential building blocks of both monoclinic structures. The main difference between them consists of the type of the Al coordination by O atoms: in tinsleyite, the clusters are designed from AlO4(OH)2 and AlO4(OH)(H2O) octahedra. In both cases, alkali Na or K atoms significantly distinct in size, act as structure regulating agents, determining the character of the developing crystal architecture. The flexibility of aluminophosphate constructions allows them to self-organize around structure-forming Na+ or K+ ions into anionic layers in Na2Al2O(PO4)2·0.12H2O or a framework (tinsleyite). The synthesis of sodium aluminophosphate under mild hydrothermal conditions and the topological resemblance of its structure with that of the mineral tinsleyite suggest a high probability of a mineral equivalent of the Na2Al2O(PO4)2·0.12H2O in nature.

Two new compounds, sodium copper nickel diorthophosphate, Na2CuNi(PO4)2 (I), and dimanganese copper diorthophosphate, Mn2Cu(PO4)2 (II), were synthesized hydrothermally, yielding single crystals, and were studied by X-ray diffraction. In the crystal structures, various transition metals of d-elements occupy symmetrically independent crystallographic positions with different coordination geometries. In the crystal structure of Na2NiCu(PO4)2, NiO6 and CuO6 octahedra share edges to form chains that PO4 groups link into a framework with cavities filled with Na atoms. Layered cationic fragments formed from dimers of MnO5 trigonal bipyramids and CuO4 square planes, sharing vertices, are connected through PO4 tetrahedra into a 3-periodic Mn2Cu(PO4)2 crystal structure. Structural correlations between Na2NiCu(PO4)2 and NaCuPO4 are discussed, and crystal–chemical details of the currently known exclusively synthetic mixed Mn/Cu and Ni/Cu phosphates are presented.