Preparation and reactivity of pendent- --CO2RhIII(phthalocyanine) bound to a poly(acrylate) backbone. Effects of the hypercoiled backbone on the association, photochemical, and thermal redox reactions of the pendent macrocycle

作者：Thomas S; Ruiz G; Ferraudi G^*

来源：Macromolecules, 2006, 39(19): 6615-6621.

DOI：10.1021/ma061264u

Poly(acrylate) was derivatized with Rh-III(pc) (pc = phthalocyanine) and the morphology of the strands was established by AFM microscopy. The strands of the polymer, poly- RhIII(pc), were seen as the strings of spherules expected for an hypercoiled poly(acrylate) backbone. Phthalocyanine pendants in a polymer, poly-Rh-III(pc), having a 1:8 stoichiometric relationship of ---Rh-III(pc) to ---CH2CH(CO2-) exhibited chemical properties different from those communicated for Rh-III(pc- tetrasulfonate)(3-) in aqueous medium or XRhIII(pc), X = Cl, Br, I, in nonaqueous media. Reactions of poly- RhIII(pc) with reducing radicals like a eaq, (CH3)(2)C center dot OH, NiL+ (L = [14]aneN(4), Me-6[14]aneN(4)), or oxidants, i. e., N-3(.), Cl-2(.-), Br-2(.-), or NiL3+ were investigated with the pulse radiolysis technique. The phthalocyanine radicals formed in these redox reactions were characterized by means of the transient UV- vis spectrum, and the kinetics of the formation and decay of the radicals were followed at various wavelengths. The photophysical and photochemical processes of poly- RhIII(pc) were studied by laser flash photolysis. The lifetime of the excited state, t = 133 ns, correlates well with the slow component of the decay of the luminescence detected in the NIR region. This transient has been assigned to a ligand field, LF, excited- state not observed in previous works when XRhIII(pc) complexes were irradiated in homogeneous solution. The thermal and photochemical properties of poly- Rh-III(pc) are discussed on the basis of environmental conditions affecting the pendent macrocycles in the strand of polymer.

• 出版日期2006-9-19