PUB - Publikationen an der Universität Bielefeld

The first Sn(I) diradical [(ADC Ph )Sn] 2 ( 4 ) based on an anionic dicarbene (ADC Ph = {CN(Dipp)} 2 CPh; Dipp = 2,6- i Pr 2 C 6 H 3 ) scaffold has been isolated as a green crystalline solid by KC 8 reduction of the corresponding bis-chlorostannylene [(ADC Ph )SnCl] 2 ( 3 ). The six-membered C 4 Sn 2 -ring of 4 containing 6pi-electrons shows a diatropic ring current, thus 4 may also be regarded as the first 1,4-distannabenzene derivative. DFT calculations suggest an open-shell singlet (OS) ground state of 4 with a remarkably small singlet-triplet energy gap (Delta E OS-T = 4.4 kcal/mol), which is consistent with CASSCF (Delta E S-T = 6.6 kcal/mol and diradical character y = 37%) calculations. The diradical 4 splits H 2 at room temperature to yield the bis-hydridostannylene [(ADC Ph )SnH] 2 ( 5 ). Further reactivity of 4 has been studied with PhSeSePh and MeOTf. © 2021 Wiley-VCH GmbH.