Four new Co(II) complexes with 2-amino-4-methylpyridine, 2-amino-3-methylpyridine, or 2-amino-5-chloropyridine: synthesis, spectroscopy, magnetic properties, and crystal structure

摘要

Solid-state structures for a series of [Co(L)_2X_2] complexes are assigned on the basis of magnetic moments, FTIR spectra, electronic spectra properties (L = 2-amino-4-methylpyridine, 2-amino-3-methylpyridine, or 2-amino-5-chloropyridine;;X = chloride or Acctate). All complexes were prepared in one-step syntheses. The crystal structure of 2-amino-4-methylpyridine with cobalt(H) chloride [Co(L)_2(Cl)_2] was solved at room temperature. This compound consists of mononuclear units consisting of two ligands linked to cobalt via the pyridine. The complex crystallizes in the orthorhombic system, spAcc group Pcan with z = 8. UV-Vis spectra show five absorption bands, attributed to d-d transitions of cobalt, ligand —> metal charge transfer, and π->π* or n->π* transitions of ligand. FTIR spectra show CoL_2X_2 vibrations at 550-300cm~(-1). The compounds show room temperature magnetic moments of 4.58-5.29 B.M., indicating high-spin cobalt(II).