138965-54-5Relevant academic research and scientific papers
Effect of the Nature of the Aromatic Groups on the Lowest Excited States of trans-1,2-Diarylethenes
Bartocci, Giampiero,Mazzucato, Ugo,Spalleti, Anna,Orlandi, Giorgio,Poggi, Gabriella
, p. 3139 - 3144 (2007/10/02)
The photophysical and photochemical behaviour of a series of diarylethenes has been investigated experimentally.For the same compounds the potential-energy curves of trans -> cis photoisomerisations and the ethenic bond orders in the S1 and T1 states have been calculated.The purpose of the study is to assess which properties of the aryls govern the photophysical behaviour of the diarylethenes.It is found that the relative energies of the La and Lb states of the larger aryl with resepct to the ethene Bu state determine to a large extent the photophysical and photochemical properties of the diarylethenes.
Triplet Intermediates in Cis-Trans Photoisomerization of 3-Chrysenylethylenes
Karatsu, Takashi,Hiresaki, Tatsuro,Arai, Tatsuo,Sakuragi, Hirochika,Tokumaru, Katsumi,Wirz, Jakob
, p. 3355 - 3362 (2007/10/02)
The effect of substitution of 3-chrysenyl group (Ar) on unsaturated double bonds in their triplet sensitized isomerization was investigated for Ar-CH=CH-R, R = tBu (BC) and Ph (SC) by means of stationary irradiations, laser flash photolyses, and MO calculations.Both olefins undergo mutual isomerization between their cis- and trans-isomers.However, BC has a unique triplet energy surface with two decay funnels at the planar trans (3t*) and twisted (3p*) conformations, which are in equilibrium with each other; 3t* undergoes either unimolecular decay to the ground-state trans isomer or triplet energy transfer to the cis isomer (quantum chain process) and 3p* decays to the ground state to give the cis and trans isomers.Tn 1 absorptions observed for BC and SC are mainly attributed to 3t* and 3p*, respectively, on the basis of semiempirical MO calculations.The populations at 3t* and 3p* are estimated.
