Generation of Alkyl and Alicyclic Carbenes

13 and 82%, respectively, in agreement with previous suggestions that the formation of (9) by photolysis of (6) occurs mainly by direct reaction of the excited state of (6). Similar experiments with the analogous precursor, 3-chloro-3-chloromethyldiazirine, showed 64% direct formation of the products, ( )- and (Z)-l,2-dichloroethene, also in accord with previous conclusions. 

Visible light irradiation (X 475 nm) of quinone diazide (21) isolated in Ar matrices at 10 K produces the corresponding carbene quantitatively. Further UV photolysis (X 360 nm) of this carbene results in formation of a labile species, which is identified as the diradical (22). The identification of (22) was supported by ROSS-BLYP/6-31G(d,P) calculations, and confirmed by deuterium labelling. 

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Generation of Alkyl and Alicyclic Carbenes. - It has been found that Ceo can act as a mechanistic probe for the formation of carbene (7) (Scheme 2) and diazo compound (8), and for the direct formation of the product (9) from the excited state (6 ), in the photolysis of 3-chloro-3-isopropyldiazirine (6). It seems that the carbene adds to 50 to form a methanofullerene, while the diazo compound adds to form a fulleroid. For photolysis of (6) at — 40°C, the results indicated formation yields of carbene (7), diazo compound (8) and product (9) of... 

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