Crystal structure of bis-{2-[(E)-(4-fluoro-benz-yl)imino-meth-yl]phenolato-κ(2) N,O}nickel(II)

Synthesis and characterisation of κ2-N,O-oxazoline-enolate complexes of nickel(ii): explorations in coordination chemistry and metal-mediated polymerisation

The synthesis and characterisation (UV-Vis, IR, X-ray diffraction, etc.) of a series of Ni(ii) complexes derived from both known and novel 2-acylmethyl-2-oxazolines (2a-g: i.e., (Z)-1-R-2-(4,4'-dimethyl-2'-oxazolin-2'-yl)eth-1-en-1-ol; R = -Ph, -2-furanyl, -p-NO2-Ph, -t-Bu, -2-thiofuranyl, p-NC-Ph, -CF3) is reported. These Ni materials (3a-g) represent the first group 10 metal complexes of this ligand class. All derivatives reported are paramagnetic (S = 1) compounds of formulae Ni(κ2-N,O-L)2 where L represents an enolate of structure (Z)-1-R-2-(4',4'-dimethyl-2'-oxazolin-2'-yl)eth-1-en-1-ate formed via proton loss from 2. The air- and moisture-stable metal complexes feature a less typical distorted seesaw-shaped disposition of binding atoms around the metal centre for six structurally characterised (X-ray) examples. Preliminary investigations indicate that 3a (R = -Ph) is a useful catalysts for olefin polymerisation in the presence of alkylaluminum reagents.

Crystal structure of bis-(2-{1-[(E)-(4-fluoro-benz-yl)imino]-eth-yl}phenolato-κ(2) N,O)palladium(II)

In the square planar [Pd(C₁₅H₁₃FNO)₂] complex, weak C—H⋯O and π–π inter­actions play important roles in the mol­ecular self-assembly, resulting in the formation of two-dimensional mol­ecular sheets which are further stacked along the b axis.

The asymmetric unit of the title complex, [Pd(C₁₅H₁₃FNO)₂], contains one half of the mol­ecule with the Pd^II cation lying on an inversion centre and is coordinated by the bidentate Schiff base anion. The geometry around the cationic Pd^II centre is distorted square planar, chelated by the imine N- and phenolate O-donor atoms of the two Schiff base ligands. The N- and O-donor atoms of the two ligands are mutually trans, with Pd—N and Pd—O bond lengths of 2.028 (2) and 1.9770 (18) Å, respectively. The fluoro­phenyl ring is tilted away from the coordination plane and makes a dihedral angle of 66.2 (2)° with the phenolate ring. In the crystal, mol­ecules are linked into chains along the [101] direction by weak C—H⋯O hydrogen bonds. Weak π–π inter­actions with centroid–centroid distances of 4.079 (2) Å stack the mol­ecules along c.