Mesoionic Dithiolates (MIDts) Derived from 1,3-Imidazole-Based Anionic Dicarbenes (ADCs).

Mesoionic dithiolates [(MIDt Ar )Li(LiBr) 2 (THF) 3 ] (MIDt Ar ={SC(NDipp)} 2 CAr; Dipp=2,6-iPr 2 C 6 H 3 ; Ar=Ph 3 a, 3-MeC 6 H 4 (3-Tol) 3 b, 4-Me 2 NC 6 H 4 (DMP) 3 c) and [(MIDt Ph )Li(THF) 2 ] (4) are readily accessible (in≥90 % yields) as crystalline solids on treatments of anionic dicarbenes Li(ADC Ar ) (2 a-c) (ADC Ar ={C(NDipp) 2 } 2 CAr) with elemental sulfur. 3 a-c and 4 are monoanionic ditopic ligands with both the sulfur atoms formally negatively charged, while the 1,3-imidazole unit bears a formal positive charge. Treatment of 4 with (L)GeCl 2 (L=1,4-dioxane) affords the germylene (MIDt Ph )GeCl (5) featuring a three-coordinated Ge atom. 5 reacts with (L)GeCl 2 to give the Ge-Ge catenation product (MIDt Ph )GeGeCl 3 (6). KC 8 reduction of 5 yields the homoleptic germylene (MIDt Ph ) 2 Ge (7). Compounds 3 a-c and 4-7 have been characterized by spectroscopic studies and single-crystal X-ray diffraction. The electronic structures of 4-7 have been analyzed by DFT calculations.