Five-coordinate zinc(II) complexes with optically active Schiff bases derived from (1R,2R)-(−)cyclohexanediamine: X-ray structure and CP MAS NMR characterization of [cyclohexylenebis(5-chlorosalicylideneiminato)zinc(II)pyridine] and [cyclohexylenebis(5-bromosalicylideneiminato)zinc(II)pyridine]

{4,4'-Di-bromo-2,2'-[cyclo-hexane-1,2-diylbis(nitrilo-methanylyl-idene)]diphenolato-κ4 O,N,N',O'}nickel(II)

In the title compound, [Ni(C20H18Br2N2O2)], the NiII ion is four-coordinated in a slightly distorted square-planar coordination geometry defined by two N atoms and two O atoms of the tetra-dentate dianionic 4,4'-di-bromo-2,2'-[cyclo-hexane-1,2-diylbis(nitrilo-methanylyl-idene)]diphenolato ligand. Pairs of complex mol-ecules are assembled by inter-molecular C-H⋯O hydrogen bonds with d(C⋯O) = 3.247 (4) Å.

Salen-Based Metal Complexes and the Physical Properties of their Porous Organic Polymers

Porous organic polymers (POPs) represent interesting candidate materials for carbon dioxide (CO2) adsorption applications owing to the permanently porous nature of the structures and the ability to vary metalloligand centres that can be incorporated as a potential means of property tuning. This work reports the synthesis and characterisation of four transition metal complexes (using M=Mn, Ni, Fe, and Pd) of the bis-bromo salen ligand, and the incorporation of these complexes into POPs with tris-(p-ethynyl)-triphenylamine to yield metallated polymers (POPMn, POPNi, POPFe, and POPPd). The POPs were shown to possess Brunauer–Emmett–Teller (BET) surface areas of up to 650m2g−1. Overall, this work provides further insight into the potential of permanently porous polymeric materials in post-combustion capture applications.

A novel nano-sized binuclear nickel(ii) Schiff base complex as a precursor for NiO nanoparticles: synthesis, characterization, DFT study and antibacterial activity

We prepared a new nano-hexadentate Schiff base and its nickel(ii) complex using an ultrasonic method, which produced NiO with an average size of 53 nm.

Aqua-{6,6'-dieth-oxy-2,2'-[ethane-1,2-diyl-bis(nitrilo-methanylyl-idene)]diphen-olato}zinc

The mononuclear zinc title complex, [Zn(C(20)H(22)N(2)O(4))(H(2)O)], was obtained by the reaction of 3-eth-oxy-salicyl-aldehyde, ethane-1,2-diamine, and zinc acetate in methanol. The Zn atom is five-coordinated by two phenolate O and two imine N atoms of the tetradentate Schiff base ligand and by one water O atom, forming a square-pyramidal geometry. In the crystal, pairs of mol-ecules are linked via inter-molecular O-H⋯O hydrogen bonds, forming dimers.

Ligand Exchange Processes on the Solvated Zinc Cation II. [Zn(H2O)4L]2+·2H2O with L = NH3, NH2(CH3), NH(CH3)2, and N(CH3)3

Water-exchange mechanisms for the complexes [Zn(H2O)4L]2+·2H2O, L = NH3, NH2CH3, NH(CH3)2, and N(CH3)3, have been studied by density functional theory calculations (B3LYP/6–311+G**). The water-exchange reactions follow an associative (A) pathway involving formation of a six-coordinate intermediate [Zn(H2O)5L]2+·H2O. Electronic and steric effects of the amine ligands influence the activation barrier and the stability of the six-coordinate intermediate.

The assembly of supramolecular boxes and coordination polymers based on bis-zinc-salphen building blocks

We report the assembly of supramolecular boxes and coordination polymers based on a rigid bis-zinc(II)-salphen complex and various ditopic nitrogen ligands. The use of the bis-zinc(II)-salphen building block in combination with small ditopic nitrogen ligands gave organic coordination polymers both in solution as well as in the solid state. Molecular modeling shows that supramolecular boxes with small internal cavities can be formed. However, the inability to accommodate solvent molecules (such as toluene) in these cavities explains why coordination polymers are prevailing over well-defined boxes, as it would lead to an energetically unfavorable vacuum. In contrast, for relatively longer ditopic nitrogen ligands, we observed the selective formation of supramolecular box assemblies in all cases studied. The approach can be easily extended to chiral analogues by using chiral ditopic nitrogen ligands.