Inorganic Chemistry, Vol.53, No.24, 13049-13060, 2014
Dual Charge-Transfer in Rhenium(I) Thioether Substituted Hexaazanaphthalene Complexes
The ligand 2,3,8,9,14,15-hexa(octyl-thioether)-5,6,11,12,17,18-hexaazatrinaphthalene (HATN-(SOct)6) and its mono-, bi-, and trinuclear Re(CO)(3)Cl complexes are reported. These are characterized by H-1 NMR spectroscopy and electrochemistry, and show broad, intense absorption across the visible wavelength region. Using time-dependent density functional theory (TD-DFT) calculations and resonance Raman spectroscopy these absorption bands are shown to be pi ? pi*, MLCT, ILCT(sulfur -> HATN), or mixed MLCT/ILCT in nature. Time-resolved infrared spectroscopy is used to probe structural changes and dynamics on short time scales and supports the assignment of a mixed MLCT/ILCT state in which both sulfur groups and one metal center act as electron donors to the HATN core.