X-ray studies, spectroscopic characterization and DFT calculations for Mn(II), Ni(II) and Cu(II) complexes with 2-benzoylpyridine

[M(SCN)2(bopy)2], where M = Mn(II), Ni(II), Cu(II), and [CuCl2(bopy)2] complexes have been prepared and studied by IR, UV-Vis and EPR spectroscopy, and X-ray crystallography. Electronic structures of the complexes were calculated using the DFT method, and the descriptions of frontier molecular orbitals and the relocation of the electron density of the compounds were determined.