Synthesis and characterization of phthalocyaninatocobalt (II) covalently bound to polyorganosiloxane

Polyorganosiloxane containing phthalocyaninatocobalt(II) in the side chain (PCPMSTACo(II)Pc) (4) was synthesized from poly[(3‐carboxypropyl)methylsiloxane] (PCPMS) (1) and 2,9,16,23‐tetraaminophthalocyaninatocobalt(II) (TACo(II)Pc) (3). The wavelength of maximum absorption of TACo(II)Pc in PCPMS‐TACo(II)Pc in solution of N,N‐dimethylformamide (DMF) is shifted depending on the polymer environment. From UV/VIS spectra of PCPMS‐TACo(II)Pc, most of the phthalocyanine moieties in PCPMS‐TACo(II)Pc may be expected to exist monomeric in methanol as well as in DMF. The glass transition temperature (Tg) of PCPMS‐TACo(II)Pc is high compared with that of PCPMS and the maximum Tg is 50°C. Further, the formation of a crosslinked film is reported, and in this film most of the phthalocyanine moieties may be expected to exist dimeric as concluded from the UV/VIS spectrum. This dimer formation and intramolecular bridges between TACo(II)Pc and carboxyl groups are considered to influence Tg, because they reduce the mobility of the main chains.