Structure and chemistry of 1-silafluorenyl dianion, its derivatives, and an organosilicon diradical dianion.

摘要: 1-Silafluorene dianion was synthesized by potassium reduction of 1,1-dichloro-1-silafluorene in refluxing THF. The X-ray structure 1,1-dipotassio-1-silafluorene (3b) shows C−C bond length equalization the five-membered silole ring and alternation six-membered benzene rings, indicating aromatic delocalization electrons ring. downfield 29Si chemical shift at 29.0 ppm theoretical calculations also support electron 3b. Dianion salt 3b underwent nucleophilic reactions with Me3SiCl EtBr to form corresponding disubstituted products. Benzaldehyde reductive coupling presence Slow oxidation yielded 1,1‘-dipotassio-1,1‘-bis(silafluorene) (16). (−38.0 ppm) 16 indicate localized negative charges silicon atoms no character. Heating a DME/hexane solution 18-crown-6 led novel diradical salt.