The direct double carbenylation of 1,4-diiodobenzene and 4,4′-dibromobiphenyl with a classical N-heterocyclic carbene, SIPr ( 1 ) (SIPr = :C{ N (2,6-iPr 2 C 6 H 3 )} 2 CH 2 CH 2 ), by means of nickel catalysis gives rise to 1,3-imidazolinium salts (SIPr)(C 6 H 4 )(SIPr)(I) 2 ( 2 ) and (SIPr)(C 6 H 4 ) 2 (SIPr)(Br) 2 ( 3 ) as off-white solids. Two-electron reduction of 2 and 3 with KC 8 cleanly yields Kekulé diradicaloid compounds (SIPr)(C 6 H 4 )(SIPr) ( 4 ) and (SIPr)(C 6 H 4 ) 2 (SIPr) ( 5 ), respectively, as crystalline solids. Structural parameters and DFT as well as CASSCF calculations suggest the closed-shell singlet ground state for 4 and 5 . Calculations reveal a very low singlet-triplet energy gap Δ E S-T for 5 (10.7 kcal mol −1 ), while Δ E S-T for 4 (29.1 kcal mol −1 ) is rather large. Two-electron reduction of bis(1,3-imidazolinium) salts 2 and 3 with KC 8 gives rise to stable diradicaloids 4 and 5 , respectively. Calculations reveal a very low singlet-triplet energy gap Δ E S-T for 5 (10.7 kcal mol −1 ), while Δ E S-T for 4 (29.1 kcal mol −1 ) is rather large.