Cu(II), Ni(II), and Hg(II) thiocyanate complexes incorporating 4,5-diazafluoren-9-one: synthesis, spectroscopic characterization, X-ray studies, and magnetic properties

This article presents a combined experimental and computational study of the complexes [Cu(dafone)2(SCN)2] (1), [Ni(dafone)2(SCN)2] (2) and [Hg(dafone)(SCN)2] (3), where dafone stands for 4,5-diazafluoren-9-one. The compounds have been studied by IR, UV–Vis spectroscopy, and single crystal X-ray diffraction. The electronic structures of these complexes have been calculated with the density functional theory (DFT) method. The spin-allowed electronic transitions of 1, 2, and 3 have been calculated with the time-dependent DFT method, and their UV–Vis spectra have been discussed on this basis.