Fine electronic state tuning of cobaltadithiolene complexes by substituent groups on the benzene ring

A series of 3,6- and 4,5-dihalogen-substituted 1,2-benzenedithiol (H2bdt) ligands, (3,6-X12-4,5-X22-1,2-H2bdt) (X2 = H, X1 = F (1a), Cl (1b), Br (1c); X1 = H, X2 = Cl (4)), and their cobalt complexes, [Cp∗Co(3,6-X12-4,5-X22-1,2-bdt)] (X2 = H, X1 = F (2a), Cl (2b), Br (2c); X1 = H, X2 = Cl (5)), were synthesized by a modified selective thiolation reaction. The 1,2-diphenyl-substituted cobaltadithiolene complex (2d) was also synthesized. The molecular structures of all cobaltadithiolene complexes were determined by single crystal X-ray diffraction analysis. Compounds 2a, 5 and 12 showed unique packing structures with intermolecular interactions that confirmed them as the first examples of half-sandwich-type metalladithiolene complexes with a Cp∗ ligand. The effects of the benzene substituent type and position on the metalladithiolene ring were investigated using UV–vis spectroscopy measurements and cyclic voltammetry. The results indicate that substitution of halogen atoms at the 3 and 6 position of the benzene ring had a larger effect on the dithiolene ring than substitution at the 4 and 5 positions.

A series of 3,6- and 4,5-dihalogen-substituted 1,2-benzenedithiol ligands and their cobalt complexes were synthesized by a modified selective thiolation reaction. The molecular structures of all the cobaltadithiolene complexes synthesized were determined. UV–vis spectroscopy and cyclic voltammetry measurements were also taken and analyzed.Figure optionsDownload as PowerPoint slide