Abstract Carbenes generated from 10-diazo-9, 9-dimethyl-9, 10-dihydro-9-silaanthracene and 10-diazo-9, 9-dimethyl-9, 10-dihydroanthracene gave hydrogen abstraction products by the triplet nature of these carbenes. The triplet dihydrosilaanthracenylidene was shown by the electron spin resonance study.