The STUDIA UNIVERSITATIS BABEÅž-BOLYAI issue article summary

The summary of the selected article appears at the bottom of the page. In order to get back to the contents of the issue this article belongs to you have to access the link from the title. In order to see all the articles of the archive which have as author/co-author one of the authors mentioned below, you have to access the link from the author's name.

  
       
         
    STUDIA CHEMIA - Issue no. 1-2 / 1999  
         
  Article:   POLYMETHINE DYES. PART II*. THE PHOTOCHROMIC BEHAVIOUR OF SOME CATIONIC DIMETHINE DYES.

Authors:  IOAN BÂLDEA, IOAN PANEA, ADRIAN CONSTANTIN APETRI. 		 
       
         
  Abstract:  The photochromic behaviour of some 1-H-indazolo-3–dimethine dyes (1-3) in dimethylformamide and 5-chloro-1,3,3.trimethyl-2-[2-(4-oxo-4-H-1-benzopyran-3-yl)ethenyl]-3-H-indolium perchlorate (4) in 1,2 dichloroethane, acetone and acetic acid has been studied. The reason for the photochromism consists of the Z/E or cis/trans isomerisation reaction. The formation of Z configuration at light exposure and thermal re-formation of E configuration at dark is supported by spectroscopic data (UV-VIS, IR and 1H- NMR) and kinetic data. Activation parameters for the cis-trans isomerisation have been determined.  
         
     
         
         
      Back to previous page