Syntheses, crystal structures and supramolecular topologies of nickel(II)-s/p/d10/NH4+ complexes derived from a compartmental ligand

The syntheses, characterization and crystal structures of ten complexes of composition [{(NiLLiI)-L-II(H2O)(2)}{(NiL)-L-II}(2)](ClO4) (1), [(NiLNaI)-L-II(ClO4)(CH3OH)](2), [((NiL)-L-II)(2)Na-I](BPh4)center dot CH3COCH3 (3), [((NiL)-L-II)(2)Rb-I](BPh4)center dot CH3COCH3 (4), [((NiL)-L-II)(2)Cs-I](ClO4)center dot CH3CN (5), [{(NiLMgII)-L-II(H2O)(3)}{(NiL)-L-II}(2)]-(ClO4)(2) (6), [(NiLCaII)-L-II(NO3)(2)(H2O)]center dot 1.5H(2)O (7), [(NiLCdII)-L-II(NO3)(2)]center dot CH3CN (8), [(NiLPbII)-L-II(NO3)(2)] (9) and [((NiL)-L-II)(2)(NH4)](PF6) (10) are reported, where H2L = N,N'-ethylenebis(3-ethoxysalicylaldimine). The crystal systems and space groups are: triclinic P (1) over bar for 1, 4, 5 and 8, monoclinic P2(1)/c for 2, 3, 7 and 9, monoclinic C2/c for 6 and monoclinic P2(1)/n for 10. In 1-10, the salen type N2O2 compartment of [L](2-) is occupied by a Ni-II ion, while the larger and open O(phenoxo)(2)O(ethoxy)(2) compartment interacts with Li-I in 1, Na-I in 2 and 3, Rb-I in 4, Cs-I in 5, Mg-II in 6, Ca-II in 7, Cd-II in 8, Pb-II in 9 and NH4+ in 10. Compounds 1 and 6 are [2 x 1 + 1 x 2] tetrametallic cocrystals of one diphenoxo-bridged dinuclear (NiLiI)-Li-II (for 1) and (NiMgII)-Mg-II(for 6) unit and two mononuclear [(NiL)-L-II] moieties. Compounds 2, 7, 8 and 9 are diphenoxo-bridged dinuclear (NiNaI)-Na-II, (NiCaII)-Ca-II and (NiCdII)-Cd-II and (NiPbII)-Pb-II systems, respectively. On the other hand, compounds 3, 4 and 5 are trinuclear (Ni2NaI)-Na-II, (Ni2RbI)-Rb-II and (Ni2CsI)-Cs-II systems, respectively, in which each of the two adjacent pairs of metal ions is diphenoxo-bridged. The rubidium(I) and cesium(I) analogues are also double-decker sandwich systems. The ammonium ion in [((NiL)-L-II)(2)(NH4)](PF6) (10) is sandwiched in between two [(NiL)-L-II] moieties due to hydrogen bonds between ammonium hydrogen atoms and O-4 compartments. Weak interaction assisted following self-assemblies are observed: dimeric in 1 and one-dimensional in 10 due to Ni center dot center dot center dot Ni weak interaction; one-dimensional in 2 due to C-H center dot center dot center dot pi and O-H center dot center dot center dot O hydrogen bonds; nice cyclic topology in 5 due to Ni center dot center dot center dot Ni interaction and C-H center dot center dot center dot O hydrogen bonds; one-dimensional in 6 due to Ni center dot center dot center dot Ni interaction and C-H center dot center dot center dot O hydrogen bond; one-dimensional in 8 due to pi center dot center dot center dot pi stacking.