Neutral and cationic cyclopentadienyliron macromolecules containing azo dyes.

A review of classes of organoiron polymers contg. azo dyes pendent to, or in their backbone which were prepd. The 1st class includes cationic organometallic polyethers, polythioethers and polynorbornenes incorporating aryl and hetaryl azo dyes. These organometallic polymers were synthesized via nucleophilic arom. substitution reactions or ring opening metathesis polymn. The resultant polymers were all brightly colored and displayed excellent soly. in polar org. solvents. Thermal anal. indicated that the polymers were thermally stable with decomplexation of the metal moiety at ∼235°. Photolytic demetalation of the polymers resulted in the decoordination of the cationic cyclopentadienyliron moieties and the formation of org. polymers. The org. polymers displayed lower glass transition temps. than their cationic organoiron analogs. The 2nd class of polymers is ferrocene based polymers with pendent cationic cyclopentadienyliron moieties. The reaction of arene complexes contg. azo dye chromophores and terminal hydroxyl groups with 1,1'-ferrocenedicarbonyl chloride gave rise to triiron complexes with a substituted ferrocene center and two terminal arene complexes contg. chloro groups. Nucleophilic arom. substitution polymn. of these triiron complexes with O- and S-contg. nucleophiles followed by photolytic demetalation gave neutral ferrocene based polymers contg. azo dyes in the backbone. Electrochem. studies of these complexes showed the redn. of the cationic Fe moieties at -1.42 V, while the neutral Fe species were oxidized at 0.89 V. UV-visible studies showed absorption at 419 nm and a bathochromic shift to 530 nm with the addn. of HCl. [on SciFinder(R)]