Structure and magnetism of Co(II) complexes with bidentate heterocyclic ligand Hsalbim derived from benzimidazole

Two mononuclear Co(II) complexes based upon 2-(1H-benzimidazol-2-yl)phenol, abbreviation Hsalbim ligand, have been prepared and studied. The structure of Hsalbim and [Co(salbim)2] have been confirmed by X-ray structure analysis. The second cobalt(II) complex matches the formula [Co(salbim)2]·(Hsalbim)·MeOH assuming a co-crystallization of one neutral ligand. The electronic spectra are consistent with the tetrahedral pattern. Magnetic susceptibility measurements down to T = 2 K along with the magnetization data until B = 7 T show that the Co(II) complexes are high-spin with a considerable zero-field splitting of the 4B1(D2d) term: D/hc = 67 and 55 cm−1, respectively.

The structure of Hsalbim and [Co(salbim)2] have been confirmed by X-ray structure analysis. The electronic spectra are consistent with the tetrahedral pattern and magnetic data gave a considerable zero-field splitting of the 4B1(D2d) term, D/hc = 67 cm−1.Figure optionsDownload as PowerPoint slideResearch highlights
► The structure of Hsalbim and [Co(salbim)2] confirms a tetrahedral coordination.
► The second cobalt(II) complex matches the formula [Co(salbim)2]·(Hsalbim)·MeOH.
► The electronic spectra are consistent with the tetrahedral pattern.
► Magnetic susceptibility and magnetization data show large zero-field splitting.