Surprising difference between two closely similar O(phenoxo)2O(ether)2 compartments as hosts for an aquated proton and a novel type of host–guest system

Synthesis, crystal structure and Hirshfeld surface analysis of di-aqua-bis-(o-phenyl-enedi-amine-κ2N,N')nickel(II) naphthalene-1,5-di-sulfonate

The reaction of o-phenyl-enedi-amine (OPD), sodium naphthalene1,5-di-sulfonate (Na2NDS) and nickel sulfate in an ethanol-water mixture yielded the title compound, [Ni(OPD)2(H2O)2]·NDS or [Ni(C6H8N2)2(H2O)2](C10H6O6S2). This salt consists of a complex [Ni(OPD)2(H2O)2]2+ cation with two bidentate OPD ligands and trans aqua ligands, and a non-coordinating NDS2- anion, which is the double-deprotonated form of H2NDS. The NiII atom is situated at a center of inversion and exhibits a slightly tetra-gonally distorted {O2N4} octa-hedral coordination environment, with four shorter equatorial Ni-N bonds [2.0775 (17) and 2.0924 (18) Å] and a longer axial Ni-O bond [2.1381 (17) Å]. The OPD ligand is located about an inversion center and is nearly coplanar with the NiN4 plane [dihedral angle 0.95 (9)°]. In the crystal, the cations and anions are connected by charge-assisted inter-molecular N-H⋯O and O-H⋯O hydrogen-bonding inter-actions into the tri-periodic network structure. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (44.1%), O⋯H/H⋯O (34.3%), C⋯H/H⋯C (14.8%) C⋯C (6.5%) (involving the cations) and O⋯H/H⋯O (50%), H⋯H (25%), C⋯H/H⋯C (15.3%), C⋯C (8.2%) (involving the anions) inter-actions.

Trigonal dodecahedral sodium coordination in a trinuclear copper(II)-sodium complex incorporating a salen-type compartmental Schiff base

A new trinuclear heterometallic complex, [(CuL)Na(CuL)]·ClO4 (1), has been prepared using a Schiff base, H2L (where H2L=N,N′-(1,2-phenylene)-bis(3-methoxysalicylideneimine) and characterized by elemental analysis, Fourier transform infra-red (FT-IR) spectroscopy, UV/Vis, magnetic, electrochemical, and single crystal X-ray diffraction methods. The structure analysis reveals that two metallo-ligand [(CuL)] units are connected to each other by a sodium ion resulting in the cationic unit [(CuL)Na(CuL)]+. Both the copper(II) ions display an almost square planar geometry while the sodium ion adopts a trigonal-dodecahedral coordination geometry. The spectroscopic and other physicochemical studies are in good agreement with the crystal structure of the complex.