Computational insight into spatial and electronic structure of bis-diketonate cobalt complexes with triphenodioxazine ligands

Abstract

A DFT study of monomeric fragments of 1D-polymer chains consisting of bis-acetylacetonate (acac), bis-trifluoromethylacetylacetonate (tfac) and bis-hexafluoroacetylacetonate (hfac) cobalt complexes with heteropentacene triphenodioxazine (TPDO) ligands revealed characteristic structural features observed in the crystal. It was established that elongation of donor–acceptor Co–N bonds stems from the presence of bulky tert-butyl groups in the TPDO, as well as repulsive interactions between the hydrogen atoms of N-donor ligands and oxygen diketonate atoms. Unusual for the high-spin cobalt(II) ion Co–O distances in Co(acac)2TPDO2 can be caused by possible population of the low-spin doublet state at increased temperature.