A unique example of a three component cocrystal of metal complexes

Abstract

The synthesis, characterization and structure of a [3 × 1 + 2 × 1 + 1 × 2] cocrystal [(Ni^IIL¹)₂Na^I(NO₃)]·[{Ni^IIL¹Na^I(H₂O)₂}{Ni^IIL¹}₂(NO₃)] derived from the hexadentate Schiff base compartmental ligand N,N′-ethylenebis(3-ethoxysalicylaldimine) (H₂L¹) are described. The compound crystallizes in the monoclinic system (space group C2/c). The structure consists of one trinuclear double-decker [(Ni^IIL¹)₂Na^I]⁺ cation, one dinuclear [Ni^IIL¹Na^I(H₂O)₂]⁺ cation and two mononuclear [Ni^IIL¹] moieties. Each of the two coordinated water molecules of the dinuclear unit is encapsulated in the O₄ cavities of the two mononuclear [Ni^IIL¹] moieties resulting in the formation of a tetranuclear self-assembly, which is further interlinked with the trinuclear sandwich species due to Ni⋯Ni interaction to result in an overall one-dimensional topology in the title compound. A unique example of a three component cocrystal of metal complexes, existence of Na^I in two entirely different environments in spite of being surrounded by the same blocking ligand and structural resemblance of sodium(I) with 3d metal ions are the major outcomes of the present investigation.