Bite-Angle-Regulated Coordination Geometries: Tetrahedral and Trigonal Bipyramidal in Ni(II) with Biphenyl-Appended (2-Pyridyl)alkylamine N,N′-Bidentate Ligands

摘要

Two simple biphenyl-appended (2-pyridyl)alkylamine N -bidentate ligands, L~(e) and L~(m), having ethylene and methylene spacers between donor groups, with bite angles L~(e) ≈ 100° and L~(m) ≈ 80°, dictate pseudotetrahedral and trigonal-bipyramidal geometries in six high-spin Ni(II)-halide complexes, [Ni(L~(e))X_(2)] and [Ni(L~(m))_(2)X](ClO_(4)) (where X = Cl~(–), Br~(–), I~(–)), respectively. The structures in the solid state, determined using X-ray crystallography, and in solution, determined using spectroscopic methods (UV–vis–NIR and paramagnetic ~(1)H NMR), which complement each other, are described.