Transition metal ion complexes with associates of porphyrin bound to a hydrophobic-hydrophilic copolymer

The interaction of dimeric forms of meso-tetraphenylporphine with Mn2+ as well as the interaction of associated forms of meso-tetra(p-aminophenyl)porphine bound to a hydrophobic-hydrophilic copolymer with Mn2+ and Fe3+ were studied by absorption, luminescence, Raman, and EPR spectroscopies. Both dimeric and associated forms of these porphyrins produced Mn2+ complexes. Manganese ions in these complexes undergo clusterization, which is accompanied by transformation of the six-line EPR signal of Mn2+ into a broad single-line signal. The EPR signal of Mn2+ in these clusters is characterized by a g-factor value typical of a free electron with half-width Delta H-pp = 50 mT. The interaction of the two-component complex with Fe3+ produces a donor-acceptor complex. The electronic spectrum of the donor-acceptor complex contains a broad band with a maximum at 760 nm. The molar extinction coefficient of the complex at 760 nm is 9.1.10(4) M-1.cm(-1), and the rate constant for its formation is K-dac = (3.9 +/- 0.6).10(6) M-1. The constants for Mn2+ binding to the organic compounds used in this work were also determined.