The striking influence of solubility on the nuclearity of cobalt NCN pincer complexes

Abstract

AbstractThe synthesis and characterization of two Co(II) complexes stabilized by NCN pincer ligands are described. The paramagnetic Co(II) complex [Co(κ3NCN-NCNCH2-iPr)Br] is obtained via a transmetalation protocol from CoBr2 and NC(C–Br)NCH2-iPr in THF. Surprisingly, the dinuclear complex [Co2(κ3NCN-μ2-NCNCH2-iPr)(μ-Cl)(Cl)2] was synthesized following the same synthetic protocol but using an ultrasonicated CoCl2 suspension instead of CoBr2 in the same solvent. Both complexes are paramagnetic species exhibiting solution magnetic moments of 1.9(1) and 5.8(3) μB, respectively. This corresponds to low-spin and high-spin d7 configurations featuring one and three unpaired electrons at the metal centers. X-ray structures of both complexes are presented. Graphical abstract