This compound displays a new structure of ladder-like 2D layers parallel to (010) consisting of [Ni(H2P2O7)(phen)2] entities with the distorted octahedral NiN4O2 coordination geometry arising from two chelating 1,10-phenanthroline ligands and diphosphate [H2P2O7] ligand bridged through stacking interactions between the neighboring 1,10-phen ligands with interplanar distances of 4.425 Е and 4.525 Е. <...> In the compound, the phen ligands bind in a bidentate fashion to the metal atoms and the ladder-like structure of the compound extends into a three-dimensional supramolecular array via hydrogen bonds (O4—H17…O5) between diphosphate groups, which delimits b axis tunnels where water molecules are located. <...> DOI: 10.15372/JSC20160825 Keywords: nickel pyrophosphate, hydrothermal synthesis, X-ray diffraction, The pyrophosphate anion PO or [O3P—O—PO3]4– plays a key role in biochemistry and aping interactions, hydrogen bonds. 4 27 plied materials science. <...> It is an interesting ligand because of its multidentate nature, and can give rise to many different coordination modes as it interacts with metal ions. <...> Transition metal phosphate and pyrophosphate anions are of great interest for their rich structural chemistry, magnetic properties, and potential applications (ion exchange, surface absorption chemistry, ionic conductivity, etc.) [ 1, 2 ]. <...> The synthesis under hydrothermal conditions in the presence of organic amine, which acts as a template or a structural-directing agent, has successfully led to many organically templated transition metal phosphates or pyrophosphates. <...> Among them nickel is of particular interest owing to its feasibility for the octahedral coordination and potential catalytic properties [ 3—7]. <...> However, the use of chelating ligands in the synthetic route and precise control of the factors influencing the synthetic process have recently © Cherni S., Zid F., Driss A., 2016 stack. 1769 – 1772 1770 allowed a number of NiII pyrophosphate coordination complexes to be isolated and investigated for their biological, magnetic and catalytic properties. <...> In such compounds the transition metal plays a key role in building interesting topologies with one-, two-, or three-dimensional networks. <...> In these atomic arrangements, the transition element is coordinated generally to the ligand via several donor atoms such as oxygen or nitrogen. <...> In recent years, many researchers have <...>