Photochromic thiophenefulgides. Photokinetics of two isopropyl derivatives
نویسندگان
چکیده
For two photochromic isopropyl-thiophenefulgides a complete photokinetic analysis is given. For one compound (Sb), the partial quantum yield for the coloming process (&c= 54%) is the highest value found for thiophenefulgides. EZ-isomerisations do not play an important role. The colouringquantum yield is temperature independent down to 20 K, whereas bleaching requires little thermal activation. In case of an adamantylidene substituted isopropyl-thiophenefulgide (Sc), the bleaching efficiency (@cs= 3 1%) is very high. Upon heating of the cyclic products, thermal bleaching occurs with an activation energy of 1 eV.
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