J . Am. Chem. SOC.1983, 105, 1051-1052
for 12, evaluated by means of isodesmic reactions, eq 1 and 2 (with M f 0 2 9 8 values in kcal/mol given in parentheses), which tend to
-
+
+
CH3C=CH (CH)2CC=CH+ CH4 (CH),+ cyclopropenium ( 4 4 . 3 9 11 (-17.916) ion (3 1 1 calcd) (25 7 16) -8.2 kcal/mol (3-21G//3-21G) (1) HC=CCH,+ proparg y r cation (28116)
+ CHICECH (44.3 16)
-
HCECCECCH,’ 12 (326 calcd)
A
-1 7.6 kcal/mol (3-2 1G//3-2 1G)
D2h
-
CHI+
+
(262i6)
(601 calcd)
C
