An Improved Model for One-Dimensional Polaronic Ferromagnetism: Electrochemically Doped Poly(m-phenylenefuchsone)

Anderson, Kraig K.; Dougherty, Dennis A.

doi:10.1002/(sici)1521-4095(199806)10:9<688::aid-adma688>3.0.co;2-m

Cited by 43 publications

(20 citation statements)

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“…Because exchange interactions between electron spin through the -conjugated system can be made relatively strong, compared to the through-space interactions in molecular solids of organic radicals, this macromolecular approach has a potential for obtaining interesting magnetic properties at relatively high temperatures, even room temperature (7 ). Although significant progress has been made in the preparation of -conjugated oligomers and polymers with large values of spin quantum number S, organic polymer magnets have remained elusive (8)(9)(10)(11)(12)(13)(14)(15). We report the observation of magnetic properties comparable to that of insulating spin glasses and blocked superparamagnets in an organic -conjugated polymer.…”

Section: Magnetic Ordering In Anmentioning

confidence: 99%

Magnetic Ordering in an Organic Polymer

Rajca

Wongsriratanakul

Rajca

2001

Science

398

283

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We describe preparation and magnetic properties of an organic π-conjugated polymer with very large magnetic moment and magnetic order at low temperatures. The polymer is designed with a large density of cross-links and alternating connectivity of radical modules with unequal spin quantum numbers ( S ), macrocyclic S = 2 and, cross-linking S = ½ modules, which permits large net S values for either ferromagnetic or antiferromagnetic exchange couplings between the modules. In the highly cross-linked polymer, an effective magnetic moment corresponding to an average S of about 5000 and slow reorientation of the magnetization by a small magnetic field (less than or equal to 1 oersted) below a temperature of about 10 kelvin are found. Qualitatively, this magnetic behavior is comparable to that of insulating spin glasses and blocked superparamagnets.

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Section: Magnetic Ordering In Anmentioning

confidence: 99%

Magnetic Ordering in an Organic Polymer

Rajca

Wongsriratanakul

Rajca

2001

Science

398

283

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“…The corresponding 2,5‐dibromopyrrole derivative together with 2,5‐didodecylbenzene bisboronic acid furnishes polymer 68 ,84 whose thermal treatment gives the polyarylene copolymer 69 with one or three pyrrolic units per repeat unit, which is otherwise not accessible. Polymer 70 46, 47 is a novel rigid‐rod type polyimide; polymer 71 85 can be used for retro Diels–Alder chemistry to access, for example, unusual poly(arylene ethinylene)s; and the reduction of polymer 72 86 yields the radical anion 73 , which was investigated as a model for one‐dimensional polaronic ferromagnetism.…”

Section: Spcmentioning

confidence: 99%

The tenth anniversary of Suzuki polycondensation (SPC)

Schlüter

2001

J. Polym. Sci. A Polym. Chem.

314

208

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This article describes the successful transfer of the Suzuki cross-coupling (SCC) reaction to polymer synthesis, one of the major developments within the last decade of polymer synthesis. The polymers prepared by Suzuki polycondensation (SPC) and its Ni-catalyzed reductive counterpart are soluble and processable poly(arylene)s that, because of their rigid and conjugated backbones, are of interest for the materials sciences. Achievable molar masses easily compete with those of traditional polyesters and polyamides. This article also provides insight into some synthetic problems associated with the transfer of SCC from low molar mass organic chemistry to high molar mass polymer chemistry by addressing issues such as monomer purity, stoichiometric balance, achievable molar masses, and defects in the polymer structure. Although the emphasis of this article is synthetic and structural issues, some potential applications of the polyarylenes obtained are briefly mentioned. Together with the enormous developments in the areas of metallocene, ring-opening metathesis, and acyclic diene metathesis polymerization, the success of SPC impressingly underlines the increasing importance of transition-metal-catalyzed CC-bondforming reactions in polymer synthesis.

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“…Numerous “quasi‐linear” and branched polymers, designed to possess large values of S , by using alternating connectivity between fCU's and radical sites have been reported. However, only relatively low values of spin, S ≤5, were found 11–13. A large body of experimental knowledge on S =1 organic diradicals (including ambient stable diradicals), with Δ E ST >0.6 kcal mol −1 ≈ RT at room temperature, does not directly translate into magnetic material.…”

Section: Connectivity Of the π Systemmentioning

confidence: 99%

“…As polymer 12 is obtained from a polyether with M w =30 kDa, an average value of S =50–60 would be expected if all unpaired electron spin are ferromagnetically coupled and no chemical defects are present. Nevertheless, the value of S ≈18 exceeds the best values of S ≈5 obtained in other high‐spin organic polymers 6, 11–13…”

Section: Polymers With Ferromagnetic–ferrimagnetic Coupling Schemementioning

confidence: 99%