Synthesis, characterization and crystal structure of diamagnetic tetracoordinated chromium (II) complexes supported by α-diimine ligands

The α-diimine ligands Arsingle bondNdouble bond; length as m-dashC(R)single bondC(R)double bond; length as m-dashNsingle bondAr (ai, bi, c) react with CrCl3(thf)3 1 in the presence of zinc to give new diamagnetic tetrahedral chromium (II) complexes supported by α-diimine ligands 2ai (i = 1–2), 2bi (i = 1–2) and 2c in good yields. All compounds were characterized by NMR and IR spectroscopy. The solid-state structure of 2b2, which crystallized in the Orthorhombic space group P212121 with unit cell parameters a = 11.825(5) Å, b = 12.034(4) Å and c = 16.393(8) Å, was established by X-ray crystallography.