부산대학교 도서관

Re(I) tricarbonyl complexes have been synthesized using bi‐ and tridentate ligands equipped with one or two hexahydro‐pyrimidopyrimidine (hpp) units attached to either a pyridine or a pyrazine ring. These complexes have been characterized by NMR, ESI‐MS, vibrational and optical spectroscopies as well as electrochemistry. Their structures were determined via single‐crystal X‐ray crystallography and modelled using both DFT and TD‐DFT methods. The complexes are non‐emissive in solution at room temperature but display emission with mixed intra ligand (major) and metal‐ligand (minor) charge transfer characters at 77 K. Additionally, both pyrazine‐based complexes appear to be emissive in the solid state, presumably due to the presence of intermolecular interactions, as observed in the crystal structure. [ABSTRACT FROM AUTHOR]