SPECTROSCOPIC PROPERTIES AND CRYSTAL STRUCTURE OF A TETRAAZA (14) ANNULENE NICKEL (II) COMPLEX CONTAINING A STRAPPED PYRIDINE GROUP

摘要

The reaction between a tetraaza (14) annulene (H_2tmtaa) and 3,3'-(2,6-pyridyldimethyleneoxy) dibenzoylchloride hydrochloride (Pydbc) led to the corresponding compound (H_2stmataa) with a strapped pyridine group. The nickel (II) complex (Ni(stmtaa)) has been prepared from H_2stmaaa and nickel (II) acetate. The mass spectra exhibit the molecular ion peaks caused by the strapped products, respectively. The infrared spectra reveal the strong stretching modes of C=O in the range of 1645-1660 cm~(-1). The structure of Ni(stmtaa) has been determined by X-ray single crystal diffraction. The crystal belongs to a monoclinic system and the space group is C2/m. The nickel (II) is coordinated through four nitrogen atoms of stmtaa to form a four-coordinate square-planar configuration. The complex has a large cavity. The average bond length of Ni to the four nitrogen atoms of stmtaa is 1.854(4) A and is very short. The displacement of the nickel (II) relative to the plane of the four nitrogen atoms of stmtaa is 0.010(1) A which is effectively coplanar. The ~1H and ~(13)C NMR spectra also confirm the structures of the strapped compounds.