Ferrocenylketene and ferrocenyl-1,2-bisketenes: direct observation and reactivity measurements.
[Structure: see text]. Ferrocenylketene (1) is calculated to be destabilized by 1.6 kcal/mol relative to phenylketene (10) by B3LYP isodesmic comparison to the corresponding alkenes. Ketene 1 generated by Wolff rearrangement in CH3CN is identified by the IR band at 2119 cm(-1) and has a rate constant for reaction with n-BuNH2 less than that for 10 by a factor of 5. 1,2-Bisferrocenyl-1,2-bisketene 18 and 1-ferrocenyl-2-trimethylsilyl-1,2-bisketene 21 were prepared by photochemical ring opening of the corresponding cyclobutenediones, and 18 undergoes rapid ring closure 67 times faster than the corresponding 1,2-diphenyl-1,2-bisketene, while bisketene 21 is longer lived than 18 by a factor of 3.2 x 10(4).
Aguilar-Aguilar
Angelica
A
Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6 Canada.
Allen
Annette D
AD
Cabrera
Eduardo Peña
EP
Fedorov
Andrei
A
Fu
Nanyan
N
Henry-Riyad
Huda
H
Leuninger
Jörg
J
Schmid
Ulrich
U
Tidwell
Thomas T
TT
Verma
Rishi
R