Photoswitching of the magnetic properties of one-dimensional π-electron systems -: Part II.: Conjugated polymers with di-hetarylethene and benzyldene-antrone fragments in the elementary units

The change in the magnetic properties of the isomeric forms of photoresponsive model polymers with photochromic di-hetarylethene, 10-benzylidene-anthrone, and 9-benzylidene-9,10-dihydroanthracene fragments in the elementary units and substituted with radical centers is investigated theoretically. Based on the band theory, the effective exchange integral is calculated for the photoisomeric one-dimensional conjugated p-electron systems. In the case of the polymers with di-hetarylethene fragments, an increase or decrease in the antiferromagnetic exchange is connected with the photoisomerization. A photoswitching between non-magnetic and ferromagnetic intramolecular exchange interaction (or vice versa) of open-ring and closed-ring photoisomers should be possible with polymers containing photochromic 10-benzylidene-anthrone and 9-benzylidene-9,10-dihydroanthracene fragments.