Tetrathiafulvalene-2,3,6,7-tetrathiolate Linker Redox-StateElucidation via S K-edge X-ray Absorption Spectroscopy

Sulfur K-edge XAS data provide a unique tool to examine oxidation states and covalency in electronically complex Sbased ligands. We present sulfur K-edge X-ray absorption spectroscopy on a discrete redox-series of Ni-based tetrathiafulvalene tetrathiolate (TTFtt) complexes as well as on a 1D coordination polymer (CP), NiTTFtt. Experiment and theory suggest that Ni—S covalency decreases with oxidation which has implications for charge transport pathways. Finally, a characteristic peak for doubly oxidized TTFtt verifies this formal redox state in the CP, NiTTFtt.