Invited Paper

Oliva, María Moreno; Delgado, M. Carmen Ruiz; Casado, Juan; Raposo, M. Manuela M.; Fonseca, A.; Hartmann, Horst; Hernández, Vı́ctor; Navarrete, Juan T. López

doi:10.1163/157404007779994214

Cited by 8 publications

(7 citation statements)

References 18 publications

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“…Such undesirable properties include nonplanar intramonomer geometry, significant intermonomer dihedral angles, highly localized frontier orbitals, and intrusion of functional groups in the area of π−π stacking. This novel design approach is fundamentally different from previous computational studies of organic semiconductors where materials were evaluated to understand charge-transport behavior at a mechanistic level, postsynthesis. – …”

Section: Discussionsupporting

confidence: 63%

n-Channel Polymers by Design: Optimizing the Interplay of Solubilizing Substituents, Crystal Packing, and Field-Effect Transistor Characteristics in Polymeric Bithiophene-Imide Semiconductors

et al. 2008

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Electron transporting (n-channel) polymer semiconductors for field-effect transistors are rare. In this investigation, the synthesis and characterization of new electron-depleted N-alkyl-2,2'-bithiophene-3,3'-dicarboximide-based pi-conjugated homopolymers and copolymers containing the 2,2'-bithiophene unit are reported. A novel design approach is employed using computational modeling to identify favorable monomer properties such as core planarity, solubilizing substituent tailorability, and appropriate electron affinity with gratifying results. Monomeric model compounds are synthesized to confirm these properties, and a crystal structure reveals a short 3.43 A pi-pi stacking distance with favorable solubilizing substituent orientations. A family of 10 homopolymers and bithiophene copolymers is then synthesized via Yamamoto and Stille polymerizations, respectively. Two of these polymers are processable in common organic solvents: the homopolymer poly(N-(2-octyldodecyl)-2,2'-bithiophene-3,3'-dicarboximide) (P1) exhibits n-channel FET activity, and the copolymer poly(N-(2-octyldodecyl)-2,2':5',2'':5'',2'''-quaterthiophene-3,3'-dicarboximide) (P2) exhibits air-stable p-channel FET operation. After annealing, P1 films exhibit a very high degree of crystallinity and an electron mobility > 0.01 cm (2) V(-1) s(-1) with a current on-off ratio of 10 (7), which is remarkably independent of film-deposition conditions. Extraordinarily, P1 films also exhibit terracing in AFM images with a step height matching the X-ray diffraction d spacing, a rare phenomenon for polymeric organic semiconductors. Another fascinating property of these materials is the air-stable p-channel FET performance of annealed P2 films, which exhibit a hole mobility of approximately 0.01 cm(2) V(-1) s(-1) and a current on-off ratio of 10(7).

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Section: Discussionsupporting

confidence: 63%

n-Channel Polymers by Design: Optimizing the Interplay of Solubilizing Substituents, Crystal Packing, and Field-Effect Transistor Characteristics in Polymeric Bithiophene-Imide Semiconductors

et al. 2008

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“…Indeed, the 1589 cm −1 mode in ExBox 3+ is strongly reminiscent of the ring stretch in 1,4-benzoquinone near the same frequency. 10 The lack of frequency shift of the methylene−pyridinium C−N stretch and the CCH in-plane bend is also consistent with "quinoidization" upon CT, as these modes are not as involved in the conjugated system. Additionally, the CC bond frequency between the pphenylene and pyridinium rings increases by ∼30 cm −1 from 4+ to 3+, again, as expected for partial "quinoidization" of the reduced arm.…”

Section: ■ Experimental Sectionmentioning

confidence: 81%

Ultrafast Conformational Dynamics of Electron Transfer in ExBox⁴⁺⊂Perylene

et al. 2013

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Multielectron acceptors are essential components for artificial photosynthetic systems that must deliver multiple electrons to catalysts for solar fuels applications. The recently developed boxlike cyclophane incorporating two extended viologen units joined end-to-end by two p-phenylene linkers-namely, ExBox(4+)-has a potential to be integrated into light-driven systems on account of its ability to complex with π-electron-rich guests such as perylene, which has been utilized to great extent in many light-harvesting applications. Photodriven electron transfer to ExBox(4+) has not previously been investigated, however, and so its properties, following photoreduction, are largely unknown. Here, we investigate the structure and energetics of the various accessible oxidation states of ExBox(4+) using a combination of spectroscopy and computation. In particular, we examine photoinitiated electron transfer from perylene bound within ExBox(4+) (ExBox(4+)⊂perylene) using visible and near-infrared femtosecond transient absorption (fsTA) spectroscopy. The structure and conformational relaxation dynamics of ExBox(3+)⊂perylene(+) are observed with femtosecond stimulated Raman spectroscopy (FSRS). From the fsTA and FSRS spectra, we observe that the central p-phenylene spacer in one of the extended viologen units on one side of the cyclophane becomes more coplanar with its neighboring pyridinium units over the first ∼5 ps after photoreduction. When the steady-state structure of chemically generated ExBox(2+) is investigated using Raman spectroscopy, it is found to have the central p-phenylene rings in both of its extended viologen units rotated to be more coplanar with their neighboring pyridinium units, further underscoring the importance of this subunit in the stabilization of the reduced states of ExBox(4+).

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“…In general, the stronger the donor and/or acceptor group, the smaller the energy difference between ground and excited states, and the longer the wavelength of absorption. 28 At this stage, a comparison could also be made between the UV-visible study of the new 5-formyl-5'-aryl-2,2'-bithiophenes 5 with 5-formyl-5'-alkoxy-and 5-N,Ndialkylamino-2,2'-bithiophenes 8, 4a formyl-N,N-dialkylamino-terthiophenes 9 4b and 5formyl-2-arylthiophenes 10 5 , recently reported by us (Figure 1). The nature of the thiophenic bridge had a clear influence on the absorption bands of compounds 5, 8, 9 and 10.…”

Section: Uv-visible Study Of Formyl-aryl-22´bithiophenesmentioning

confidence: 99%

Synthesis of 5-aryl-5′-formyl-2,2′-bithiophenes as new precursors for nonlinear optical (NLO) materials

et al. 2009

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Invited Paper

Cited by 8 publications

References 18 publications

n-Channel Polymers by Design: Optimizing the Interplay of Solubilizing Substituents, Crystal Packing, and Field-Effect Transistor Characteristics in Polymeric Bithiophene-Imide Semiconductors

n-Channel Polymers by Design: Optimizing the Interplay of Solubilizing Substituents, Crystal Packing, and Field-Effect Transistor Characteristics in Polymeric Bithiophene-Imide Semiconductors

Ultrafast Conformational Dynamics of Electron Transfer in ExBox⁴⁺⊂Perylene

Synthesis of 5-aryl-5′-formyl-2,2′-bithiophenes as new precursors for nonlinear optical (NLO) materials

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Invited Paper

Cited by 8 publications

References 18 publications

n-Channel Polymers by Design: Optimizing the Interplay of Solubilizing Substituents, Crystal Packing, and Field-Effect Transistor Characteristics in Polymeric Bithiophene-Imide Semiconductors

n-Channel Polymers by Design: Optimizing the Interplay of Solubilizing Substituents, Crystal Packing, and Field-Effect Transistor Characteristics in Polymeric Bithiophene-Imide Semiconductors

Ultrafast Conformational Dynamics of Electron Transfer in ExBox4+⊂Perylene

Synthesis of 5-aryl-5′-formyl-2,2′-bithiophenes as new precursors for nonlinear optical (NLO) materials

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Ultrafast Conformational Dynamics of Electron Transfer in ExBox⁴⁺⊂Perylene