Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9605676 | Journal of Photochemistry and Photobiology A: Chemistry | 2005 | 8 Pages |
Abstract
Complexation of Ni(II), Co(II) and Zn(II) with the photomerocyanines obtained under steady irradiation of spiroindolinonaphthooxazines containing benzothiazolyl substituent in the naphthooxazine moiety induces a slight hypsochromic shift of its visible absorption band and drastically slows down its thermal bleaching in the dark. As a result, the relaxation time at 20°C ranges from 2 to 42 min, the actual value depending on the metal ion and compound. High 'colourabilities' up to 5 Ã 104 Mâ1 cmâ1 (É = 6 Ã 104 Mâ1 cmâ1) are calculated from the absorbance values obtained by extrapolation to t = 0 of the room temperature linearly descending kinetic curves ln A/t. Complexation with Ni(II), Co(II) and Zn(II) allows the spiroindolinonaphthooxazines to isomerize to their open-coloured form even under dark conditions giving a complex spectroscopically identical to the photoinduced product and greatly increasing its lifetime to several days.
Related Topics
Physical Sciences and Engineering
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Authors
Bojana G. Jeliazkova, Stela Minkovska, Todor Deligeorgiev,