E. L. Tae, Zhendong Zhu, M. Platz
Jun 19, 1999
Citations
0
Influential Citations
7
Citations
Journal
Journal of Physical Chemistry A
Abstract
The photochemistry of 2-methoxy-2-methyl-5,5-dipropyl-Δ3-1,3,4-oxadiazoline (1a) and 2,2-dimethoxy-5,5-dipropyl-Δ3-1,3,4-oxadiazoline (1b) was investigated. Photolysis (300 nm) of these compounds in solution leads to fragmentation to 4-diazoheptane (major), which slowly forms the corresponding azine. Fragmentation to form 4-heptanone is also observed. Yields of 4-diazoheptane in CH2Cl2 are much larger than those in pentane. 4-Diazoheptane can be trapped with 1-pentene to form a pyrazoline or with methanol to form 4-methoxyheptane. The pyrazoline can be decomposed photochemically to form 1,1,2-tripropylcyclopropane. In solution, 4-diazoheptane is inefficiently photolyzed to dipropylcarbene (DPC), which can be trapped with piperidine or with pyridine in laser flash photolysis experiments. Analysis of the piperidine and pyridine data indicates that the lifetime of DPC in cyclohexane, methylene chloride, or Freon-113 (CF2ClCFCl2) solution at ambient temperature is controlled by 1,2 hydrogen migration to form ...