Magnetic Properties of Poly[5-(4-acryloyloxyphenyl)-10,15,20-triphenylporphinatocopper(II)] and Poly[5-(4-acryloyloxyphenyl)-10,15,20-triphenylporphinatosilver(II)]

Abstract

The magnetic properties of polymers containing tetraphenylporphin-Cu(II) (TPP-Cu(II)) or tetraphenylporphin-Ag(II) (TPP-Ag(II)) in the side chains were studied by the magnetic susceptibility (XM) measurement (4-300 K) and ESR spectroscopy. The values of XM for the polymer containing TPP-Cu(II) were found to obey the Curie-Weiss law, and a magnetic moment showed the occurrence of a weak antiferromagnetic interaction between Cu(II) ions. The values of XM for the polymer containing TPP-Ag(II) did not obey any simple equation such as the Curie-Weiss law or Bleaney-Bowers equation and simulation of temperature dependence of XM showed the presence of strongly interacting sites. This strong interaction may possibly arise from a hyperexchange interaction through C=O groups situated among the Ag(II) ions. An ESR study also supported the presence of this interaction between the side groups in a polymer chain. KEY WORDS Metalloporphin Polymer I Magnetic Property I Magnetic Susceptibility I Electron Exchange I ESR I Antiferromagnetic Interaction 1

Radical Polymerization of 5-(4-Vinylphenyl)-10,15,20-triphenyl Porphyrin

“…Although the silver(II) complex of polyAOTPP showed strong antiferromagnetic interaction, the silver(II) complex of monomer (AOTPP) showed a typical paramagnetic property. 2 Polymer effect on the magnetic ordering was found in the system, but the origin of the exchange interactions among these paramagnetic side chains still remains unknown. The strong antiferromagnetic interaction of polyAOTPP-Ag 11 is likely due to a superexchange interactions through oxygen atoms of carbonyl group suggested from an IR spectrum of silver(II) complex.…”

Magnetic Properties of Polymers Containing Tetraphenyl-porphinatosilver(II) as Their Side Chains

“…Previously, 3 we used TPPAg(II) as a model compound of polyAOTPPAg(II). However, this compound is not considered suitable for the model compound of polyAOTPPAg(II), because C = 0 groups seem to play an important role for the occurrence of the antiferromagnetic interaction.…”

“…However, this compound is not considered suitable for the model compound of polyAOTPPAg(II), because C = 0 groups seem to play an important role for the occurrence of the antiferromagnetic interaction. 3 Thus, it is necessary to measure the magnetic behavior of POTPPAg(II) instead ofTPPAg(II) as a model compound. The temperature dependence of magnetic susceptibility of POTPPAg(II) is shown in Figure I.…”

“…On the other hand, a symmetrical line of an isotropic g factor was observed in the case of polyAOTPPAg(II), indicating that an exchange of electron spins through the side chains in the polymer is much larger than those in the model compounds, and consequently, that the magnetic field on any electron is apparently isotropic in polyAOTPPAg(Il). 3 The ESR spectra of poly[AOTPPAg(Il)-co-MMA] are shown in Figure 5. At first sight, the ESR spectra of poly[AOTPPAg(Il)-co-/ __ ,,,.,…”

“…Kamachi et al undertook the preparation of copolymers containing TPPAg(II) or TPPCu(II) and nitroxyl in their side chains. Before preparing the copolymer, Kamachi et al 3 synthesized poly[S-(4-acryloyloxyphenyl)-10, 15,20-triphenylporphinatosilver(II)] (polyAOTPPAg(II)) in their side chains and found that the polymer was strongly antiferromagnetic. They suggested that the origin of the strong antiferromagnetic interaction of the polymer is superexchange interactions between TPPAg(II) moieties in their side chains through the carbonyl oxygen.…”