Synthesis of novel bithiophene derivatives with an organosilanylene bridge, and their applications to electron-transporting materials in EL devices

Ohshita, Joji; Kai, Hiroyuki; Sumida, Tomohisa; Kunai, Atsutaka; Adachi, Akira; Sakamaki, Koichi; Okita, Kohei

doi:10.1016/s0022-328x(01)01257-8

Cited by 22 publications

(17 citation statements)

References 25 publications

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“…[2,[9][10][11][12] Bearing in mind the remarkable properties of silicon-containing molecules, several works in the field of molecular magnetism have been devoted to the syntheses and characterization of model compounds based on paramagnetic centers (organic radicals or paramagnetic metal ions) linked by organosilicon units. [3,9,[13][14][15][16][17][18][19][20] The connection of spin-bearing moieties through silicon-containing units was achieved in such a way that the magnetic interaction may take place through the molecular skeleton via the set of conjugated bonds available in such systems following two different approaches involving either the use of silanylene or disilan-A C H T U N G T R E N N U N G ylene units as spin couplers. These studies revealed that 1) the silicon atom, when it is part of a single pathway spacer, can act as a magnetic coupler, 2) as in other hetero-A C H T U N G T R E N N U N G atom-containing couplers, the nature of the magnetic exchange depends on the connectivity of the paramagnetic centers, and finally 3) the strength of the magnetic interaction strongly depends on the orbital overlap between the silanylene or disilanylene coupler and the spin-bearing p systems.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Theoretical Studies of Magnetic Exchange in Silole‐Bridged Diradicals

Roques

Gerbier

Schatzschneider

et al. 2006

Chemistry A European J

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Five bis(tert-butylnitroxide) diradicals connected by a silole (7 a-d) or a thiophene (12) ring as a coupler were studied. Compound 12 crystallizes in the orthorhombic space group Pna2(1) with a = 20.752(5), b = 5.826(5), and c = 34.309(5) A. X-ray crystal structure determination, electronic spectroscopy, variable-temperature EPR spectroscopy, SQUID measurements and DFT computations (UB3LYP/6-31+G*) were used to study the molecular conformations and electronic spin coupling in this series of molecules. Whereas compounds 7 b, 7 c, and 7 d are quite stable both in solution and in the solid state, 7 a and 12 undergo a partial electronic rearrangement to both a diamagnetic quinonoidal form and a monoradical species owing to the fact that they correspond to the open form of a pi-conjugated Kekulé structure. In the solid state, magnetic measurements indicate that the diradicals are all antiferromagnetically coupled, as expected from their topology. These interactions are best reproduced by means of a "Bleaney-Bowers" model that gives values of J = -142.0 cm(-1) for 7 a, -1.8 cm(-1) for 7 b, -1.3 cm(-1) for 7 c, -4.2 cm(-1) for 7 d, and -248.0 cm(-1) for 12. The temperature dependence of the EPR half-field transition in frozen dichloromethane solutions is consistent with singlet ground states and thermally accessible triplet states for diradicals 7 b, 7 c, and 7 d with DeltaE(T-S) values of 3.48, 2.09, and 8 cm(-1), respectively. No evidence of a populated triplet state was found for diradicals 7 a and 12. Similarities between the DeltaE(T-S) and J values (DeltaE(T-S) = -2 J) clearly show the intramolecular origin of the observed antiferromagnetic interaction. Analyses of the data with a "Karplus-Conroy"-type equation enabled us to establish that the silole ring, as a whole, allows a more efficient magnetic coupling of the two nitroxide radicals attached to its 2,5-positions than the thiophene ring. This superiority probably originates from the nonaromaticity of the silole which thus permits a better magnetic interaction through it. DFT calculations also support the experimental results, indicating that the magnetic exchange pathway preferentially involves the carbon pi system of the silole.

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Section: Introductionmentioning

confidence: 99%

Experimental and Theoretical Studies of Magnetic Exchange in Silole‐Bridged Diradicals

Roques

Gerbier

Schatzschneider

et al. 2006

Chemistry A European J

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“…Like other silole-containing compounds, DTSs have low-lying LUMO and may be used as the electron-transport for electroluminescent devices [7][8][9]. They are electrochemically active and the cyclic voltammograms (CVs) revealed an irreversible anodic peak.…”

Section: Introductionmentioning

confidence: 99%

Anodic polymerization of dithienosilole and electroluminescent properties of the resulting polymer

Ohshita

Hamamoto

Kimura

et al. 2005

Journal of Organometallic Chemistry

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“…Two thiophene rings combined with a C–C single bond are almost coplanar with twisting angles of 6.40 and 16.37° (Figure b). Ohshita reported that the reaction of 1,1,2,2-tetrachloro-1,2-dialkyldisilane with 3,3′-dilithiobithiophene derivatives produced similar bicyclic disilanes with the Me or i -Bu substituents at the Si atom and that the trans isomer is formed preferentially . The reaction mixture from eq does not contain any trans isomer 2′ .…”

Section: Resultsmentioning

confidence: 58%

“…The absorption and emission bands of 2 (λ max = 336 nm, λ em = 418 nm) are similar to those of DTSH 2 (λ max = 337 nm, λ em = 411 nm) except for a shoulder peak at 360 nm. The reported dimer, dDTSMe, also exhibited a shoulder at 376 nm . They may be assigned to a vibrational structure, although support by theoretical calculations has not been obtained at present.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of 4,4-Dihydrodithienosilole and Its Unexpected Cyclodimerization Catalyzed by Ni and Pt Complexes

et al. 2017

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4,4-Dihydrodithienosilole (DTSH 2 ) was isolated from a mixture of 3,3′-dibromobithiophene, n-BuLi, and H 2 SiCl 2 and was fully characterized. The reaction of DTSH 2 with a Pt(0) complex, prepared in situ from [Pt(PCy 3 ) 2 ] and DPPE (1,2bis(diphenylphosphino)ethane), produced a bis(silyl)platinum complex [Pt(DTSH) 2 (dppe)] (1) with two hydrodithienosilole ligands. DTSH 2 undergoes cyclodimerization accompanied by skeletal rearrangement to afford a cis-fused bicyclic compound (2) upon heating the solution in the presence of a catalytic amount of 1 or [Ni(PPh 3 ) 4 ]. The product has a Si−Si bond that bridges two Si atoms, separated by 2.309(1) Å. Bicyclic disilane 2 forms the Pt complex (3) with two Si ligands and retaining the 10-membered macrocycle ligand via the Si−Si bond cleavage.

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Synthesis of novel bithiophene derivatives with an organosilanylene bridge, and their applications to electron-transporting materials in EL devices

Cited by 22 publications

References 25 publications

Experimental and Theoretical Studies of Magnetic Exchange in Silole‐Bridged Diradicals

Experimental and Theoretical Studies of Magnetic Exchange in Silole‐Bridged Diradicals

Anodic polymerization of dithienosilole and electroluminescent properties of the resulting polymer

Synthesis of 4,4-Dihydrodithienosilole and Its Unexpected Cyclodimerization Catalyzed by Ni and Pt Complexes

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