Α,ω‐di([5]trovacenyl) Sulfides TVC–Sn–TVC (n = 1–4) and TVC–SCH2S–TVC: a Study in Intramolecular Communication

The oligosulfur-bridged dinuclear paramagnetic complexes di([5]trovacenyl) sulfide (3''), di([5]trovacenyl) trisulfide (5''), di([5]trovacenylthio)methane (6''), and di([5]trovacenyl) tetrasulfide (7'') have been prepared by the metathesis reactions of [5]trovacenyllithium with SCl2, and [5]lithiotrovacenylthiolate (2') with SCl2, CH2Cl2, and S2Cl2, respectively, in which 2. was obtained by the reaction of [5]trovacenyllithium with 1 equiv. of elemental sulfur at ambient temperature. Combined with the previously reported di([5]trovacenyl) disulfide (4''), these complexes have been systematically investigated by means of cyclic voltammetry, electron paramagnetic resonance (EPR) spectroscopy, magnetic susceptometry, and/or X-ray diffraction analysis, which reveal weak antiferromagnetic spinspin exchange interactions. The monosulfur-bridged 3'', in particular, displays the strongest intramolecular spinspin exchange interaction of vertical bar JEPR vertical bar = 2.8 cm1 and J? = 1.39 cm1. This study also indicates that with an increasing number of sulfur atoms in the bridge, the intramolecular communication of biradicals throught the 1D saturated sulfur atom bridge significantly weakens both in solution and in the solid state compared to those of unsaturated carbon-based bridges.