Porphyrin polymer complexes

The first example of catalysis by a polymer-metal complex was presented by Lautsch et al. u3 Metalloporphyrin was linked to a poly(phenylalanine) chain by a peptide bond. The catalytic properties of this polymer-Fe(III)porphyrin complex were compared with Fe(III)porphyrin in the oxidative reaction of phenylenedi-amine. The catalytic activity of the polymer complex was twice as large as that for the corresponding analog. 

Example of the synthesis of a positively charged cross-linked polystyrene containing covalently bound porphyrin 18 mg (0.0244 mmol) of the tetra-aminophenylporphyrin zinc(II) complex was dissolved in 50 mL DMF. 1 g of the cross-linked chloromethylated polystyrene and then after 30 min 0.5 mL of triethylamine were added. The mixture was heated while slowly stirring for 24 h at 80 °C. The isolated polymer was treated with DMF. The amount of polymer-bonded porphyrin was determined from these solutions taking the absorption at... 

A macromolecule provides a suitable fimctional group for either complexation with metal ions of metal salts or attaching metal complexes into the macromolecular matrix through a coordination bond typical examples of the former are silver-polymer complexes, while cobalt porphyrins incorporated on a polymer backbone through coordination bonding are examples of the latter. 

Figure 9-14. Oxygen and nitrogen permeability coeffieients (/ 02 and Pn2) for the cobalt porphyrin-polymer complex menftrane. The cob

Measurement of Oxygen-Binding Rate Constants for Solid State Cobalt Porphyrin-Polymer Complexes (Section 9.2.4) [27]... 

Polymer VII belongs to a group of conjugated polymers containing porphyrin or phthalocyanine complexes synthesized by Lu et al. [16]. Here, the polymer backbone consists of phenylene vinylene moieties, which facilitate hole trans-... 

Polymer RuCO-porphyrins 102 and 103 (Scheme 48) were used for the cyclopropanation reaction of styrenes but they were also tested in the epoxidation reaction. Contrary to cyclopropanation for which moderate enantioselectivities and low activities were observed, these Ru porphyrin complexes gave good ee (up to 76%) and activity (up to 89%) for AE of unfimctionalized olefines [204], Recently, Simmoneaux showed that iron catalyst 326 derived from electropolymerized tetraspirofluorenyl porphyrin (Scheme 138) led to moderate yields without chiral induction [205],... 

It should be noted that a number of SPC polymers which contain other heterocycles have been prepared, motivated by their promising optical or electrical properties. Examples include pyridine (65) [123], pyrrole (66) [124], oxadiazole (67) [125], selenophene (68) [126], benzo[2,l,3]thiadiazole (69) [127], benzo[2,l,3]selenadiazole (70) [126], perylene bisimide (71) [128], 1,4-diketo- pyrrolo[3,4-c]pyrrole-l,4-dione (72 and 73) [127,129], and triphenyleamine (74) [127] as part of the polymer backbone by SPC (Figure 19c). Specifically for metal complexation, porphyrin [130], difluoroboraindacene [131], bipyridine [132], phenanthroHne [113], terpyridine [133, 134], and the like [123] were embedded in the backbone. In this context, an interesting report was submitted by Rehahn et al., in which l,l -ferrocenyl units were incorporated into a PPP (Figure 22.20). Due to a low-energy barrier for rotation around the Cp-Fe-Cp axes (Cp = cyclopentadienyl), the obtained polymer 75 was assumed to take randomly coiled conformations [135]. 

Matsufuji, A., S. Nakazawa, and K. Yamamoto (2001). Electrocatalysis of the reduction of dioxygen by 7t-conjugated polymer complexes with dinuclear cobalt porphyrin. J. Inorg. Organomet. Polym. 11, 47-61. 

The association of porphyrin and fullerene electron acceptors in LB films can also proceed via a stepwise, noncovalent formation of the assembly, as demonstrated by Shinkai and Ikeda (Figure 13.88). The host-guest interaction of Ceo with homooxa-calix[3]arene is the noncovalent interaction that assists film formation The fullerene absorption in the host-guest complex is used to determine a surface concentration of 1.4 x 10 ° molcrn" in the Ceo layer, which is then further covered with the polymer-sustained porphyrins 165 or 166. Porphyrin surface concentrations are then controlled by UV-visible absorption and are found to be 7.6 X 10 and 5.5 x 10 for 165 and 166, respectively. Photocurrent measurements performed under irradiation at 420 nm, with a 1.36 mW cm for a coating of 165, and at 430 nm, with a 1.53mWcm for a coating of 166, in... 

Fig. 3.6 Zinc porphyrins bearing oligoaniline with a pyridine moiety at the terminal of the chain. AFM image of the self-assembled branched polymer complex...

Porphyrin-based complexes pass their redox sensitivity on to the corresponding polymers. Advanced conjugated main-chain structures with attached dendrons have been introduced [220]. Grafting of porphyrin-zinc main-chain polymers onto carbon nanotubes was reported [221]. An interesting example dealing with a nonelectrochemically switched polymer was recently given. Here, polymers with porphyrin-iron end groups could be switched between linear and cyclic polymers by a dimerization procedure (Fig. 14) [222, 223],... 

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