A Benzene‐1,3,5‐Triaminyl Radical Fused with Zn<sup>II</sup>‐Porphyrins: Remarkable Stability and a High‐Spin Quartet Ground State

Shimizu, Daiki; Osuka, Atsuhiro

doi:10.1002/anie.201801080

Cited by 50 publications

(30 citation statements)

References 43 publications

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“…12 m decreased its χT values upon warming, clearly indicating its triplet ground state and reflecting the meta connectivity of the two formal cation radical centers. The estimated exchange interaction ( J 1 / k B =+27 K) was smaller than that for a multiporphyrin‐based triaminyl triradical ( J 1 / k B =+125 K) and trimethylenemethane diradical ( J 1 / k B > +715 K), consistent with the smaller spin density at the aminium cation radical center (see Figure S9‐2).

true H = - 2 J_{1} s_{a} s_{b} + μ_{B} \sum_{i = a, b} s_{i} g_{i} H_{normale normalx}

true χ T = f_{1} \frac{{2 N}_{A} g^{2} {μ_{B}}^{2}}{k_{B} [3 + e x p (- 2 J_{1} / k_{B} T ()])} \frac{T}{T - θ}

true χ T = f_{1} \frac{{2 N}_{A} g^{2} {μ_{B}}^{2}}{k_{B} [3 + e x p (- 2 J_{1} / k_{B} T ()])} + f_{2} \frac{N_{A} g^{2} {μ_{B}}^{2}}{2 k_{B}}

…”

Section: Figurementioning

confidence: 75%

meta‐ and para‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals

Kato

Osuka

2019

Angew Chem Int Ed

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meta-and para-Phenylenediamine-fused nickel(II) porphyrin dimers were synthesized by S N Ar reaction of meso,b,b-trichloro nickel(II) porphyrin with meta-and paraphenylenediamines and subsequent Pd-catalyzed intramolecular CÀHa rylation. Their tetrachlorinated dication diradicals are very stable,allowing SQUIDmagnetometry and revealing clear open-shell characters for both meta and para isomers with ferro-and anti-ferromagnetic interactions,r espectively. The nitrogen analogue of Thielesh ydrocarbon usually displays predominant closed-shell nature but its hidden diradical characters increase either in at wisted conformation or upon insertion of an additional phenylene spacer.T he observed distinct diradical nature of the para-congener indicates that diradical properties can be enhanced also by efficient spin delocalization.

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true H = - 2 J_{1} s_{a} s_{b} + μ_{B} \sum_{i = a, b} s_{i} g_{i} H_{normale normalx}

true χ T = f_{1} \frac{{2 N}_{A} g^{2} {μ_{B}}^{2}}{k_{B} [3 + e x p (- 2 J_{1} / k_{B} T ()])} \frac{T}{T - θ}

true χ T = f_{1} \frac{{2 N}_{A} g^{2} {μ_{B}}^{2}}{k_{B} [3 + e x p (- 2 J_{1} / k_{B} T ()])} + f_{2} \frac{N_{A} g^{2} {μ_{B}}^{2}}{2 k_{B}}

…”

Section: Figurementioning

confidence: 75%

meta‐ and para‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals

Kato

Osuka

2019

Angew Chem Int Ed

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show abstract

true H = - 2 J_{1} s_{a} s_{b} + μ_{B} \sum_{i = a, b} s_{i} g_{i} H_{normale normalx}

true χ T = f_{1} \frac{{2 N}_{A} g^{2} {μ_{B}}^{2}}{k_{B} [3 + e x p (- 2 J_{1} / k_{B} T ()])} \frac{T}{T - θ}

true χ T = f_{1} \frac{{2 N}_{A} g^{2} {μ_{B}}^{2}}{k_{B} [3 + e x p (- 2 J_{1} / k_{B} T ()])} + f_{2} \frac{N_{A} g^{2} {μ_{B}}^{2}}{2 k_{B}}

…”

Section: Figurementioning

confidence: 75%

meta‐ and para‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals

Kato

Osuka

2019

Angewandte Chemie

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meta‐ and para‐Phenylenediamine‐fused nickel(II) porphyrin dimers were synthesized by SNAr reaction of meso,β,β‐trichloro nickel(II) porphyrin with meta‐ and para‐phenylenediamines and subsequent Pd‐catalyzed intramolecular C−H arylation. Their tetrachlorinated dication diradicals are very stable, allowing SQUID magnetometry and revealing clear open‐shell characters for both meta and para isomers with ferro‐ and anti‐ferromagnetic interactions, respectively. The nitrogen analogue of Thiele's hydrocarbon usually displays predominant closed‐shell nature but its hidden diradical characters increase either in a twisted conformation or upon insertion of an additional phenylene spacer. The observed distinct diradical nature of the para‐congener indicates that diradical properties can be enhanced also by efficient spin delocalization.

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“…Moreover, carbon magnets have been widely studied by both experimental and theoretical techniques [6,7]. Finally, a combination of organic and inorganic materials has been reported to show remarkable stability and a high-spin quartet ground state [8].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Carbon Showing Weak Antiferromagnetic Behavior at a Low Temperature

Otaki¹,

Hirokawa²,

Goto³

2019

Condensed Matter

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In this short communication, we report a new carbon material prepared from meta-linked polyaniline that exhibits weak antiferromagnetic interactions at low temperature. The synthesis of poly(meta-aniline), abbreviated as m-PANI, was conducted using the Ullmann reaction with the aid of Cu+ as a catalyst in the presence of K2CO3. After the generation of radical cations by vapor-phase doping with iodine, carbonization was performed to prepare carbon polyaniline (C-PANI), which comprises condensed benzene rings. Analysis with a superconducting quantum interference device revealed that the resultant carbon exhibits antiferromagnetism at low temperatures. The discovery of this weak antiferromagnetic carbon may contribute to the development of carbon magnets.

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A Benzene‐1,3,5‐Triaminyl Radical Fused with Zn^II‐Porphyrins: Remarkable Stability and a High‐Spin Quartet Ground State

Cited by 50 publications

References 43 publications

meta‐ and para‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals

meta‐ and para‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals

meta‐ and para‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals

Synthesis of Carbon Showing Weak Antiferromagnetic Behavior at a Low Temperature

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A Benzene‐1,3,5‐Triaminyl Radical Fused with ZnII‐Porphyrins: Remarkable Stability and a High‐Spin Quartet Ground State

Cited by 50 publications

References 43 publications

meta‐ and para‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals

meta‐ and para‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals

meta‐ and para‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals

Synthesis of Carbon Showing Weak Antiferromagnetic Behavior at a Low Temperature

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A Benzene‐1,3,5‐Triaminyl Radical Fused with Zn^II‐Porphyrins: Remarkable Stability and a High‐Spin Quartet Ground State