The aldimine effect in bis(imino)pyridine complexes: non-planar nickel(i) complexes of a bis(aldimino)pyridine ligandElectronic supplementary information (ESI) available: Procedures for the synthesis of 4-7; ORTEP diagrams of 4, 5, and 7a; X-ray crystallographic details; X-ray data in cif format for 4-7(a); 1H NMR spectra for 4 and 5; UV-vis data for 6 and 7, and additional computational data and details, including Cartesian coordinates for all optimized structures. CCDC 1040543-1040547. For ESI

Reduction of bis(aldimino)pyridine nickel( ii ) dihalide forms a non-planar bis(aldimino)pyridine nickel( i ) halide. Unlike the previously reported square-planar bis(ketimino)pyridine nickel chloride, for which the spin density was localized on the ligand, the present species demonstrate N py -Ni-X angles of 156°-162° and significant spin density at the metal inferred from EPR measurements and DFT calculations. One-electron reduction of bis(aldimino)pyridine nickel( ii ) forms a non-planar bis(aldimino)pyridine nickel halide featuring a significant spin density at the Ni center.