Trans-cis-photoisomerization of 14C-labelled 1,3-diphenylpropenes. Part 1.—Direct photolysis

Abstract

trans-1,3-Diphenyl[1-¹⁴C]propene, cis-1,3-diphenyl[3-¹⁴C]propene and their inactive counterparts have been photoisomerized at λ= 254 nm and λ > 280 nm. The quantum yields at 254 nm were Φ(cis→trans)= 0.068 and Φ(trans→cis)= 0.105. Oxygen did not substantially affect the quantum yields and the position of the ¹⁴C was not influenced by the photoisomerization at any wavelength.